摘要
随着高速铁路技术的发展，铝合金在高速动车组列车制造中得到了越来越多的应用。作为轨道车辆生产制造的核心技术，铝合金的焊接技术直接影响车辆的质量、生产成本和行车安全。然而，使用传统的熔化焊方法焊接铝合金存在的主要焊接性问题为：焊缝中的气孔、焊接热裂纹、接头变形及软化等。这些焊接性问题与铝合金的物理性质等因素有关，很难得到根本的解决，这一定程度上制约了铝合金在高速列车制造中的更广泛的应用。搅拌摩擦焊（FSW）是一种新型的固相连接技术，被认为是解决铝合金焊接性问题最为有效的方法之一。因此，开展高速列车用6005A-T6铝合金FSW接头的组织与性能研究，具有重要的理论意义和实用价值。
本文首先系统、深入地研究了6005A-T6铝合金FSW接头的组织与性能特点。研究结果表明，6005A-T6铝合金FSW接头可分为焊核区（NZ）、热机械影响区（TMAZ）、热影响区（HAZ）和母材（BM）。BM组织呈纤维状，晶粒内部分布着大量细小的针状β''相，β''与-Al基本呈共格关系，在BM晶界上连续地分布着单质Si相和Q相，沿晶界存在较宽的沉淀无析出带（PFZ）。NZ在FSW过程中经历了动态再结晶，同时还有沉淀相的溶解。TMAZ的突出特点为沿一定方向弯曲变形的晶粒，基体中存在着高密度的位错。在NZ和TMAZ的晶界上仅存在极少量的单质Si相。HAZ的微观组织是不均匀的，靠近TMAZ的HAZ（记为HAZ1）中为较均匀的近等轴晶粒，而靠近BM的HAZ（记为HAZ2）晶粒仍具有纤维状特点。HAZ晶粒内部的主要沉淀相为棒/板状β'相、板状Q'相和针状β''相，β'相和Q'相与-Al基体呈半共格关系。随着距焊缝中心距离减小，HAZ中β''相减少而β'相和Q'相增多且明显粗化。HAZ晶界上非连续地分布着单质Si和Q相，晶界两侧的PFZ宽度有所减小。6005A-T6铝合金FSW接头的显微硬度分布呈W型。BM具有最高的硬度值，NZ的硬度较TMAZ更高，硬度最小值位于HAZ1内，随着距焊缝中心距离的增加，HAZ硬度显著升高。显微硬度的变化主要与晶内沉淀相的种类、尺寸和密度有关。拉伸性能测试结果表明，FSW接头的抗拉强度可达到母材强度的70%以上，延伸率可达母材的75%以上。FSW接头具有较母材更高的抗晶间腐蚀性能。母材晶界大量的第二相（单质Si相和Q相）与两侧的PFZ易形成原电池，导致其抗晶间腐蚀性能明显降低。NZ晶界上的第二相明显减少，因此显著提高了其抗晶间腐蚀性能。
较系统地研究了焊接参数（焊接速度、旋转速度、下压量）和焊后时效处理对6005A-T6铝合金FSW接头微观组织及力学性能的影响规律。焊接速度的增大、搅拌头旋转速度的减小或下压量的降低，将导致焊接热输入减小，NZ和HAZ1晶粒细化，HAZ1沉淀相（β'相和Q'相）有细化的趋势，NZ硬度略有升高；反之则焊接热输入增大，NZ和HAZ1晶粒粗化，HAZ1沉淀相（β'相和Q'相）有粗化的趋势，NZ硬度略有降低。不适当的焊接参数导致产生孔洞、飞边等焊接缺陷，明显影响接头的拉伸性能及焊接质量。焊后自然时效处理对接头组织及硬度具有一定的影响。随着时效时间的延长，NZ和TMAZ发生自然时效现象，由过饱和固溶体→团簇→GP区，宏观表现为硬度的逐渐提高，而HAZ的组织和硬度在自然时效过程中无明显变化。焊后人工时效处理可使基体中固溶的溶质原子以沉淀相的方式析出，因此有利于提高接头的整体硬度水平和抗拉强度。优化焊接参数是提高接头力学性能的有效途径。采用二次回归正交试验方法优化的6005A-T6铝合金FSW参数为：焊接速度370mm/min，搅拌头旋转速度为1381r/min，下压量为0.11mm，FSW接头的抗拉强度计算值为222.4MPa，FSW接头抗拉强度的试验值为212.7MPa，计算值与试验值的误差为4.36%。
依据粘着摩擦机制，建立了FSW过程的产热方程，计算表明，在FSW过程中对产热的贡献依次为轴肩凹端面（83.9%）、搅拌针侧面（11.0%）、轴肩外侧面（2.7%）、搅拌针底端面（2.4%）。因此，在温度场的有限元模拟计算时考虑轴肩外侧面的产热作用是必要的。在此基础上，通过ANSYS有限元模拟软件对FSW热过程进行了数值模拟分析。数值模拟得到的FSW接头不同位置的热循环曲线与实测结果基本吻合，并且能够较好的反映出焊接参数对接头温度场的影响规律。
根据6005A-T6铝合金FSW接头沉淀相形貌的研究结果，将沉淀相形貌假定为更接近于实际情况的圆柱形，以析出热力学、生长动力学和强化理论为基础，建立了6005A铝合金组织演变模型和强化模型，从而实现了6005A-T6铝合金FSW接头组织的定量描述及接头显微硬度分布的预测，预测结果与试验结果基本一致。
With the rapid development of high-speed railway technology, aluminum alloys havegained wide application in manufacturing of high-speed trains. As the key technology for thehigh-speed train manufacturing, the welding of aluminum alloys strongly influences on thequality and cost of trains and traffic safety. However, the conventional fusion welding foraluminum alloys often brings some defects such as porosities, hot cracks, distortion andsoftening. It is very difficult to solve these weldability problems because they are relatedwith physical properties of aluminum alloys. These problems limit more widespreadapplications of aluminium alloys in manufacturing of high-speed trains. As a solid-statejoining technique, friction stir welding (FSW) was considered to be the more desired methodfor joining aluminium alloys. Therefore, it has great theoretical significance and practicalvalues to carry out the study on microstructures and properties of friction stir welding jointsof6005A-T6aluminum alloy used in high-speed trains.
Firstly, the characteristics of microstructures and properties of6005A-T6aluminumalloy FSW joints were studied systematacially. The results showed the FSW joint of6005A-T6aluminum alloy was composed of nugget zone (NZ), thermo-mechanicallyaffected zone (TMAZ), heat-affected zone (HAZ) and base metal (BM). The BM exhibitedfibrous microstructure, and a large number of fine needle-shaped β'' precipitates, which arebasically coherent with-Al matrix, were observed within BM grains. Elemental Si and Qprecipitates continuously distributed at grain boundaries of the BM. Additionally, wideprecipitate-free zones (PFZ) were also found along grain boundaries of the BM. NZunderwent dynamic recrystallization and precipitates dissolution during FSW. TMAZ ischaracterized by elongated grains with a high density of dislocations. A few elemental Si wasfound at grain boundaries of NZ and TMAZ. The microstructure of HAZ was non-uniform.HAZ close to the TMAZ (named HAZ1) exhibited equiaxed grains, while HAZ close to the BM (named HAZ2) had fibrous grain morphology similar to BM. The predominantprecipitates in HAZ were rod/lath-shaped β', lath-shaped Q' and needle-shaped β'' phases.With the distance decreasing away the weld center, the density of β'' phases within HAZdecreased while β' and Q' phases within HAZ increased and coarsed. It should be noted thatβ' and Q' phases are semi-coherent with-Al matrix. Elemental Si and Q precipitatesdiscontinuously distributed at grain boundaries of HAZ. In addition, the PFZ width of HAZwas smaller than that of BM. The hardness distribution of FSW joint approximates to theW-type. BM has the highest hardness value, and NZ has higher hardness than TMAZ. Theminimum hardness is located at the HAZ1. The hardness of HAZ increased with increasingthe distance away the weld center. The hardness changes are associated with theintragranular precipitate evolution, i.e. the kind, size and density of the intragranularprecipitates. The results of tensile tests showed that the tensile strength and elongation ofFSW joints are higher than70%and75%of those of BM, respectively. Moreover, FSW jointexhibited stronger intergranular corrosion (IGC) resistance than BM. The presence ofcontinuous cathodic precipitates (Si and Q phases) at grain boundaries and the PFZ alonggrain boundaries of the BM resulted in the severe IGC susceptibility. The significantelimination of IGC in NZ is related to the low volume fraction of intergranular precipitates.
Secondly, effects of welding parameters (welding speed, rotational speed and plungedepth) and postweld treatments on microstructures and mechanical properties of FSW jointsof6005A-T6aluminum alloy were studied. The results indicated that the increasing ofwelding speed, decreasing of rotational speed or decreasing of plunge depth resulted in thedecreasing of heat input, grain refining for NZ and HAZ1, precipitates (β' and Q') refining forHAZ1and slight increasing in hardness of NZ. Inadequate welding parameters should causedefect formation in the joint such as holes and flash, which deteriorate the tensile properties.Postweld natural aging (PWNA) treatment affected microstructures and hardness distributionof FSW joints. The microstructure evolution in NZ and TMAZ during PWNA wassupersaturated solid solution (SSS)→clusters→GP zones. As a result, the hardness increasedwith increasing PWNA time. However, the microstructure and hardness of HAZ wereunaffected by PWNA. Postweld artificial aging (PWAA) led the solution atoms to form β'' precipitates which are benefit for increasing the hardness level and tensile strength of joints.Furthermore, the welding parameters were optimized by means of quadratic regressionorthogonal combination test, and the optimal parameters for6005A-T6aluminum alloy FSWare the welding speed of370mm/min, rotational speed of1381r/min, and plunge depth of0.11mm. The calculated tensile strength of FSW joint for the optimal parameters was222.4MPa and the experimental one was212.7MPa, the error between the calculated value andexperimental result being4.36%.
Furthermore, an analytical model for the heat generation in FSW was established, basedon the hypothesis of sticking condition between tool and workpiece. Results showed that thecontributions for heat generation of shoulder concave, pin side, shoulder side and pin tip are83.9%,11.0%,2.7%and2.4%, respectively. This implies that it is neccesary to consider theeffect of shoulder side on heat generation in condition of numerical modelling for FSWthermal process. Hence, the temperature fields of joint during FSW were analyzed by meansof numerical simulation with the ANSYS software. Results showed excellent concordance inthermal cycles of different locations between simulated ones and experimentalmeasurements. The effects of welding parameters on the temperature distribution could beclarified by the thermal model.
Finally, based on the microstructural investigation for6005A aluminum alloy joints,considering cylinder-shaped morphology for precipitates is closer to the real situation. Then,mirostructural evolution model and hardening model of6005A aluminium alloy wereestablished, based on the precipitation thermodynamics, growth kinetics and hardeningtheory. The quantitative description of the microstructural evolution during FSW and theprediction of mechanical properties for the FSW joints were realized by means of themirostructural evolution model and hardening model combined with the thermal model. Thecalculated results of hardness distribution of FSW joints showed concordance withexperimental measurements.
引文
[1] Williams J C, Starke Jr E A. Progress in structural materials for aerospace systems[J].Acta Materialia,2003,51(19):5775-5799.
[2] Nakai M, Eto T. New aspect of development of high strength aluminum alloys foraerospace applications[J]. Materials Science and Engineering: A,2000,285(1):62-68.
[3] Heinz A, Haszler A, Keidel C, et al. Recent development in aluminium alloys foraerospace applications[J]. Materials Science and Engineering: A,2000,280(1):102-107.
[4] Miller W S, Zhuang L, Bottema J, et al. Recent development in aluminium alloys for theautomotive industry[J]. Materials Science and Engineering: A,2000,280(1):37-49.
[5] http://news.cnal.com/industry/2011/05-26/1306391820228032.shtml
[6]王炎金,丁国华,王俊玖.铝合金车体制造技术在中国的发展现状和展望[J].焊接,2005(10):5-7.
[7]王炎金.铝合金车体焊接工艺[M].北京：机械工业出版社,2010.
[8]周振丰.焊接冶金学（金属焊接性）[M].北京：机械工业出版社，1996.
[9]斯重遥,周振丰,钱百年.焊接手册：材料的焊接[M].北京：机械工业出版社，1992.
[10] Thomas W M. Friction stir butt welding[P]. International Patent Application No.PCT/GB92/0220,1991.
[11] Knipstr m K E, Pekkari B. Friction stir welding process goes commercial[J]. WeldingJournal,1997,76(9):55-57.
[12]马宗义.搅拌摩擦焊接与加工技术研究进展[J].科学观察,2009,4(5):53-54.
[13] Mishra R S, Ma Z Y. Friction stir welding and processing[J]. Materials Science andEngineering R,2005,50(1):1-78.
[14] Nandan R, DebRoy T, Bhadeshia H. Recent advances in friction-stir welding–process,weldment structure and properties[J]. Progress in Materials Science,2008,53(6):980-1023.
[15] Threadgill P L, Leonard A J, Shercliff H R, et al. Friction stir welding of aluminiumalloys[J]. International Materials Reviews,2009,54(2):49-93.
[16] GB/T16474-1996.变形铝及铝合金牌号表示方法.
[17] Gupta A K, Lloyd D J, Court S A. Precipitation hardening in Al–Mg–Si alloys with andwithout excess Si[J]. Materials Science and Engineering: A,2001,316(1):11-17.
[18] Edwards G A, Stiller K, Dunlop G L, et al. The precipitation sequence in Al–Mg–Sialloys[J]. Acta Materialia,1998,46(11):3893-3904.
[19] Murayama M, Hono K, Miao W F, et al. The effect of Cu additions on the precipitationkinetics in an Al-Mg-Si alloy with excess Si[J]. Metallurgical and materials transactionsA,2001,32(2):239-246.
[20]张建新,高爱华,陈昊.合金元素对Al–Mg–Si系铝合金组织及性能的影响[J].铸造技术,2007,28(3):373-375.
[21]李绍禄,潘青林,尹志民,等.微量Mn对Al–Mg–Si合金微观组织与拉伸性能的影响[J].中国有色金属学报,2002,12(5):972-976.
[22]刘宏,赵刚,刘春明,等. Mn对Al-Mg-Si-Cu铝合金车身板组织和性能的影响[J].东北大学学报(自然科学版),2005,26(4):245-248.
[23]何立子. Al–Mg–Si系合金组织性能[D].沈阳：东北大学，2001.
[24] Chakrabarti D J, Laughlin D E. Phase relations and precipitation in Al–Mg–Si alloyswith Cu additions[J]. Progress in Materials Science,2004,49(3):389-410.
[25] Marioara C D, Andersen S J, Stene T N, et al. The effect of Cu on precipitation inAl–Mg–Si alloys[J]. Philosophical magazine,2007,87(23):3385-3413.
[26] Marioara C D, Andersen S J, Zandbergen H W, et al. The influence of alloy compositionon precipitates of the Al-Mg-Si system[J]. Metallurgical and Materials Transactions A,2005,36(3):691-702.
[27] Svenningsen G, Lein J E, Bj rgum A, et al. Effect of low copper content and heattreatment on intergranular corrosion of model AlMgSi alloys[J]. Corrosion science,2006,48(1):226-242.
[28] Svenningsen G. Intergranular corrosion of AA6000-series aluminium alloys[D].Trondheim: Norwegian University of Science and Technology,2005.
[29] Zhan H, Mol J M C, Hannour F, et al. The influence of copper content on intergranularcorrosion of model AlMgSi (Cu) alloys[J]. Materials and corrosion,2008,59(8):670-675.
[30] Zandbergen HW, Andersen SJ, Jansen J. Structure determination of Mg5Si6particles inAl by dynamic electron diffraction studies. Science1997;277:1221-5.
[31] Murayama M, Hono K. Pre-precipitate clusters and precipitation processes in Al–Mg–Sialloys[J]. Acta materialia,1999,47(5):1537-1548.
[32] Miao W F, Laughlin D E. Precipitation hardening in aluminum alloy6022[J]. ScriptaMaterialia,1999,40(7):873-878.
[33] Donnadieu P, Carsughi F, Redjaimia A, et al. Nanoscale Hardening Precipitiation inAlMgSi Alloys: A Transmission Electron Microscopy and Small-Angle NeutronScattering Study[J]. Journal of applied crystallography,1998,31(2):212-222.
[34]桑益. Al–Mg–Si合金的多级时效硬化特性和析出行为[D].长沙：湖南大学，2012.
[35] Chen J H, Costan E, Van Huis M A. Atomic Pillar–based nanoprecipitates strengthenAlMgSi alloys. Science,2006,312:416-419.
[36] Andersen S J, Zandbergen H W, Jansen J, et al. The crystal structure of the β″phase inAl–Mg–Si alloys[J]. Acta Materialia,1998,46(9):3283-3298.
[37] Vissers R, Van Huis M A, Jansen J, et al. The crystal structure of the β′phase inAl–Mg–Si alloys[J]. Acta Materialia,2007,55(11):3815-3823.
[38] Tors ter M, Lefebvre W, Marioara C D, et al. Study of intergrown L and Q′precipitatesin Al–Mg–Si–Cu alloys[J]. Scripta Materialia,2011,64(9):817-820.
[39] Jacobs M H. The structure of the metastable precipitates formed during ageing of anAl-Mg-Si alloy[J]. Philosophical Magazine,1972,26(1):1-13.
[40]赵乃勤.合金固态相变[M].长沙：中南大学出版社,2008.
[41]胡赓祥，蔡珣.材料科学基础[M].上海：上海交通大学出版社,2000.
[42] Poole W J, Wang X, Lloyd D J, et al. The shearable-non-shearable transition inAl–Mg–Si–Cu precipitation hardening alloys: implications on the distribution of slip,work hardening and fracture[J]. Philosophical Magazine,2005,85(26-27):3113-3135.
[43]王国庆，赵衍华.铝合金的搅拌摩擦焊接[M].北京：中国宇航出版社,2010.
[44] Bobby Kannan M, Dietzel W, Zeng R, et al. A study on the SCC susceptibility offriction stir welded AZ31Mg sheet[J]. Materials Science and Engineering: A,2007,460:243-250.
[45] Woo W, Choo H, Prime M B, et al. Microstructure, texture and residual stress in afriction-stir-processed AZ31B magnesium alloy[J]. Acta materialia,2008,56(8):1701-1711.
[46] Commin L, Dumont M, Masse J E, et al. Friction stir welding of AZ31magnesiumalloy rolled sheets: Influence of processing parameters[J]. Acta Materialia,2009,57(2):326-334.
[47] Afrin N, Chen D L, Cao X, et al. Microstructure and tensile properties of friction stirwelded AZ31B magnesium alloy[J]. Materials Science and Engineering: A,2008,472(1):179-186.
[48] Suhuddin U, Mironov S, Sato Y S, et al. Grain structure evolution during friction-stirwelding of AZ31magnesium alloy[J]. Acta Materialia,2009,57(18):5406-5418.
[49] Lee W B, Yeon Y M, Jung S B. Joint properties of friction stir welded AZ31B–H24magnesium alloy[J]. Materials Science and Technology,2003,19(6):785-790.
[50] Pareek M, Polar A, Rumiche F, et al. Metallurgical evaluation of AZ31B-H24magnesium alloy friction stir welds[J]. Journal of materials engineering andperformance,2007,16(5):655-662.
[51] Zhou L, Liu H J, Liu P, et al. The stir zone microstructure and its formation mechanismin Ti–6Al–4V friction stir welds[J]. Scripta Materialia,2009,61(6):596-599.
[52] Zhang Y, Sato Y S, Kokawa H, et al. Microstructural characteristics and mechanicalproperties of Ti–6Al–4V friction stir welds[J]. Materials Science and Engineering: A,2008,485(1):448-455.
[53] Ramulu M, Edwards P D, Sanders D G, et al. Tensile properties of friction stir weldedand friction stir welded-superplastically formed Ti–6Al–4V butt joints[J]. Materials&Design,2010,31(6):3056-3061.
[54] Cho H H, Han H N, Hong S T, et al. Microstructural analysis of friction stir weldedferritic stainless steel[J]. Materials Science and Engineering: A,2011,528(6):2889-2894.
[55] Saeid T, Abdollah-Zadeh A, Assadi H, et al. Effect of friction stir welding speed on themicrostructure and mechanical properties of a duplex stainless steel[J]. MaterialsScience and Engineering: A,2008,496(1):262-268.
[56] Sato Y S, Nelson T W, Sterling C J. Recrystallization in type304L stainless steel duringfriction stirring[J]. Acta materialia,2005,53(3):637-645.
[57] Xue P, Xie G M, Xiao B L, et al. Effect of heat input conditions on microstructure andmechanical properties of friction-stir-welded pure copper[J]. Metallurgical andMaterials Transactions A,2010,41(8).
[58] Xie G M, Ma Z Y, Geng L. Development of a fine-grained microstructure and theproperties of a nugget zone in friction stir welded pure copper[J]. Scripta Materialia,2007,57(2):73-76.
[59] Shen J J, Liu H J, Cui F. Effect of welding speed on microstructure and mechanicalproperties of friction stir welded copper[J]. Materials&Design,2010,31(8):3937-3942.
[60] Lee W B, Jung S B. The joint properties of copper by friction stir welding[J]. MaterialsLetters,2004,58(6):1041-1046.
[61] Firouzdor V, Kou S. Formation of liquid and intermetallics in Al-to-Mg friction stirwelding[J]. Metallurgical and Materials Transactions A,2010,41(12):3238-3251.
[62] Abdollah-Zadeh A, Saeid T, Sazgari B. Microstructural and mechanical properties offriction stir welded aluminum/copper lap joints[J]. Journal of Alloys and Compounds,2008,460(1):535-538.
[63] Tanaka T, Morishige T, Hirata T. Comprehensive analysis of joint strength for dissimilarfriction stir welds of mild steel to aluminum alloys[J]. Scripta Materialia,2009,61(7):756-759.
[64] Amancio-Filho S T, Sheikhi S, Dos Santos J F, et al. Preliminary study on themicrostructure and mechanical properties of dissimilar friction stir welds in aircraftaluminium alloys2024-T351and6056-T4[J]. Journal of Materials ProcessingTechnology,2008,206(1):132-142.
[65] Kostka A, Coelho R S, Dos Santos J, et al. Microstructure of friction stir welding ofaluminium alloy to magnesium alloy[J]. Scripta Materialia,2009,60(11):953-956.
[66] Colligan K. Material flow behaviour during friction welding of aluminum[J]. WeldingJournal,1999,75(7):229s-237s.
[67] Reynolds A P. Visualisation of material flow in autogenous friction stir welds[J].Science and technology of welding&joining,2000,5(2):120-124.
[68] Seidel T U, Reynolds A P. Visualization of the material flow in AA2195friction-stirwelds using a marker insert technique[J]. Metallurgical and materials Transactions A,2001,32(11):2879-2884.
[69] Schmidt H N B, Dickerson T L, Hattel J H. Material flow in butt friction stir welds inAA2024-T3[J]. Acta Materialia,2006,54(4):1199-1209.
[70] London B, Mahoney M, Bingel W, et al. Material flow in friction stir weldingmonitored with Al–SiC and Al–W composite markers[J]. Friction Stir Welding andProcessing II. The Minerals, Metals and Materials Society (TMS),2003:3-12.
[71]栾国红.搅拌摩擦焊流变特性研究[J].航空制造技术,2003,11:22-25.
[72]张华.镁合金搅拌摩擦焊接工艺及其接头成形机理研究[D].哈尔滨：哈尔滨工业大学,2005.
[73]王希靖,韩晓辉,李常锋,等.厚铝合金板搅拌摩擦焊塑性金属不同深度的水平流动状况[J].中国有色金属学报,2005,15(2):198-204.
[74]张忠科.搅拌摩擦焊接过程的多场检测及耦合关键问题研究[D].兰州：兰州理工大学,2010.
[75]赵衍华.2014-T6铝合金搅拌摩擦焊接工艺及塑性体流动研究[D].哈尔滨：哈尔滨工业大学,2006.
[76] Murr L E, Li Y, Flores R D, et al. Intercalation vortices and related microstructuralfeatures in the friction-stir welding of dissimilar metals[J]. Material ResearchInnovations,1998,2(3):150-163.
[77] Li Y, Murr L E, McClure J C. Solid-state flow visualization in the friction-stir weldingof2024Al to6061Al[J]. Scripta materialia,1999,40(9):1041-1046.
[78] Shinoda T. Effect of Tool Angle on Metal Flow Phenomenon in Friction Stir Welds[C]//3rd International Friction Stir Welding Symposium, Japan,2001.
[79] Kumar K, Kailas S V. The role of friction stir welding tool on material flow and weldformation[J]. Materials Science and Engineering: A,2008,485(1):367-374.
[80] Arbegast W J. A flow-partitioned deformation zone model for defect formation duringfriction stir welding[J]. Scripta Materialia,2008,58(5):372-376.
[81] Arbegast W J. Modeling friction stir joining as a metalworking process[C]//HotDeformation of Aluminum Alloys III, TMS Annual Meeting, San Diego, CA.2003:313-327.
[82] Chen Z W, Pasang T, Qi Y. Shear flow and formation of Nugget zone during friction stirwelding of aluminium alloy5083-O[J]. Materials Science and Engineering: A,2008,474(1):312-316.
[83] Chen Z W, Cui S. On the forming mechanism of banded structures in aluminium alloyfriction stir welds[J]. Scripta Materialia,2008,58(5):417-420.
[84] Guerra M, Schmidt C, McClure J C, et al. Flow patterns during friction stir welding[J].Materials characterization,2002,49(2):95-101.
[85] Bendzsak G J, North T H, Smith C B. An experimentally validated3D model forfriction stir welding[C]//The2nd International Symposium on Friction Stir Welding.2000:1-12.
[86] Nandan R, Roy G G, Lienert T J, et al. Three-dimensional heat and material flow duringfriction stir welding of mild steel[J]. Acta Materialia,2007,55(3):883-895.
[87]周明智,雷党刚,梁宁,等.搅拌摩擦焊三维粘塑性热力耦合有限元数值模拟[J].焊接学报,2010(2):5-9.
[88] Colegrove P A, Shercliff H R.3-Dimensional CFD modelling of flow round a threadedfriction stir welding tool profile[J]. Journal of Materials Processing Technology,2005,169(2):320-327.
[89]张昭.搅拌摩擦焊接过程中材料行为及力学响应的数值模拟[D].大连：大连理工大学,2006.
[90] Zhang H W, Zhang Z, Chen J T.3D modeling of material flow in friction stir weldingunder different process parameters[J]. Journal of Materials Processing Technology,2007,183(1):62-70.
[91] Xu S, Deng X, Reynolds A P, et al. Finite element simulation of material flow in frictionstir welding[J]. Science and Technology of Welding&Joining,2001,6(3):191-193.
[92] Schmidt H, Hattel J. Modelling heat flow around tool probe in friction stir welding[J].Science and Technology of Welding&Joining,2005,10(2):176-186.
[93]赵衍华,林三宝,贺紫秋,等.三维搅拌摩擦焊接过程数值模拟[J].焊接学报,2006,27(6):75-78.
[94]韩晓辉.铝合金搅拌摩擦焊三维流场研究[D].兰州：兰州理工大学,2005.
[95] Nandan R, Roy G G, DebRoy T. Numerical simulation of three-dimensional heattransfer and plastic flow during friction stir welding[J]. Metallurgical and MaterialsTransactions A,2006,37(4):1247-1259.
[96] Tang W, Guo X, McClure J C, et al. Heat input and temperature distribution in frictionstir welding[J]. Journal of Materials Processing and Manufacturing Science,1998,7:163-172.
[97] Hwang Y M, Kang Z W, Chiou Y C, et al. Experimental study on temperaturedistributions within the workpiece during friction stir welding of aluminum alloys[J].International Journal of Machine Tools and Manufacture,2008,48(7):778-787.
[98] Fujii H, Cui L, Maeda M, et al. Effect of tool shape on mechanical properties andmicrostructure of friction stir welded aluminum alloys[J]. Materials Science andEngineering: A,2006,419(1):25-31.
[99] Reynolds A P, Tang W, Khandkar Z, et al. Relationships between weld parameters,hardness distribution and temperature history in alloy7050friction stir welds[J].Science and Technology of Welding&Joining,2005,10(2):190-199.
[100] Ouyang J, Yarrapareddy E, Kovacevic R. Microstructural evolution in the friction stirwelded6061aluminum alloy (T6-temper condition) to copper[J]. Journal of MaterialsProcessing Technology,2006,172(1):110-122.
[101] Maeda M, Liu H, Fujii H, et al. Temperature Field in the Vicinity of FSW-Tool DuringFriction Stir Welding of Aluminium Alloys[J]. Welding in the World,2005,49(3-4):69-75.
[102] Colegrove P A, Shercliff H R. Experimental and numerical analysis of aluminiumalloy7075-T7351friction stir welds[J]. Science and Technology of Welding&Joining,2003,8(5):360-368.
[103] Xu W, Liu J, Luan G, et al. Temperature evolution, microstructure and mechanicalproperties of friction stir welded thick2219-O aluminum alloy joints[J]. Materials&Design,2009,30(6):1886-1893.
[104] Simar A, Pardoen T, De Meester B. Effect of rotational material flow on temperaturedistribution in friction stir welds[J]. Science and Technology of Welding&Joining,2007,12(4):324-333.
[105] Sato Y S, Urata M, Kokawa H. Parameters controlling microstructure and hardnessduring friction-stir welding of precipitation-hardenable aluminum alloy6063[J].Metallurgical and Materials Transactions A,2002,33(3):625-635.
[106] Dong P, Li H, Sun D, et al. Effects of welding speed on the microstructure andhardness in friction stir welding joints of6005A-T6aluminum alloy[J]. Materials&Design,2013,45:524-531.
[107] Hashimoto T, Jyogan S, Nakata K, et al. FSW joints of high strength aluminumalloy[C]//Proceedings of the First International Symposium on Friction Stir Welding,Paper.1999(S9-P3).
[108] Arbegast W J, Hartley P J. Friction stir weld technology development at LockheedMartin Michoud Space System--an overview[J]. ASM International, Trends inWelding Research(USA),1999:541-546.
[109] Frigaard, Grong, Midling O T. A process model for friction stir welding of agehardening aluminum alloys[J]. Metallurgical and materials transactions A,2001,32(5):1189-1200.
[110] Chao Y J, Qi X, Tang W. Heat transfer in friction stir welding—experimental andnumerical studies[J]. Journal of manufacturing science and engineering,2003,125(1):138-145.
[111] Song M, Kovacevic R. Thermal modeling of friction stir welding in a movingcoordinate system and its validation[J]. International Journal of Machine Tools andManufacture,2003,43(6):605-615.
[112]张华.镁合金搅拌摩擦焊接工艺及其接头成形机理研究[J].哈尔滨：哈尔滨工业大学,2005.
[113] Schmidt H, Hattel J, Wert J. An analytical model for the heat generation in friction stirwelding[J]. Modelling and Simulation in Materials Science and Engineering,2004,12(1):143.
[114] Simar A, Lecomte-Beckers J, Pardoen T, et al. Effect of boundary conditions and heatsource distribution on temperature distribution in friction stir welding[J]. Science andTechnology of Welding&Joining,2006,11(2):170-177.
[115] Simar A, Bréchet Y, De Meester B, et al. Sequential modeling of local precipitation,strength and strain hardening in friction stir welds of an aluminum alloy6005A-T6[J].Acta Materialia,2007,55(18):6133-6143.
[116] Di S, Yang X, Luan G, et al. Comparative study on fatigue properties betweenAA2024-T4friction stir welds and base materials[J]. Materials Science andEngineering: A,2006,435:389-395.
[117] Lemmen H J K, Alderliesten R C, Benedictus R. Evaluating the fatigue initiationlocation in friction stir welded AA2024-T3joints[J]. International Journal of Fatigue,2011,33(3):466-476.
[118] Srinivasan P B, Arora K S, Dietzel W, et al. Characterisation of microstructure,mechanical properties and corrosion behaviour of an AA2219friction stir weldment[J].Journal of alloys and compounds,2010,492(1):631-637.
[119] Bussu G, Irving P E. The role of residual stress and heat affected zone properties onfatigue crack propagation in friction stir welded2024-T351aluminium joints[J].International Journal of Fatigue,2003,25(1):77-88.
[120] Liu H J, Zhang H J, Huang Y X, et al. Mechanical properties of underwater friction stirwelded2219aluminum alloy[J]. Transactions of Nonferrous Metals Society of China,2010,20(8):1387-1391.
[121] Liu H J, Zhang H J, Yu L. Effect of welding speed on microstructures and mechanicalproperties of underwater friction stir welded2219aluminum alloy[J]. Materials&Design,2011,32(3):1548-1553.
[122] Ayd n H, Bayram A, Durgun. The effect of post-weld heat treatment on themechanical properties of2024-T4friction stir-welded joints[J]. Materials&Design,2010,31(5):2568-2577.
[123] Genevois C, Deschamps A, Vacher P. Comparative study on local and globalmechanical properties of2024T351,2024T6and5251O friction stir welds[J].Materials Science and Engineering: A,2006,415(1):162-170.
[124] Liu H J, Fujii H, Maeda M, et al. Tensile properties and fracture locations offriction-stir-welded joints of2017-T351aluminum alloy[J]. Journal of MaterialsProcessing Technology,2003,142(3):692-696.
[125] Biallas G, Braun R, Donne C D, et al. Mechanical properties and corrosion behavior offriction stir welded2024-T3[C].1st international symposium on friction stir welding,Thousand Oaks, CA.1999.
[126] Steuwer A, Dumont M, Altenkirch J, et al. A combined approach to microstructuremapping of an Al–Li AA2199friction stir weld[J]. Acta Materialia,2011,59(8):3002-3011.
[127] Srinivasan P B, Arora K S, Dietzel W, et al. Characterisation of microstructure,mechanical properties and corrosion behaviour of an AA2219friction stir weldment[J].Journal of alloys and compounds,2010,492(1):631-637.
[128] Genevois C, Deschamps A, Denquin A, et al. Quantitative investigation ofprecipitation and mechanical behaviour for AA2024friction stir welds[J]. ActaMaterialia,2005,53(8):2447-2458.
[129] Shukla A K, Baeslack III W A. Study of process/structure/property relationships infriction stir welded thin sheet Al–Cu–Li alloy[J]. Science and Technology of Welding&Joining,2009,14(4):376-387.
[130] Fonda R W, Bingert J F. Microstructural evolution in the heat-affected zone of afriction stir weld[J]. Metallurgical and materials transactions A,2004,35(5):1487-1499.
[131] Hirata T, Oguri T, Hagino H, et al. Influence of friction stir welding parameters ongrain size and formability in5083aluminum alloy[J]. Materials Science andEngineering: A,2007,456(1):344-349.
[132] Zhou C, Yang X, Luan G. Fatigue properties of friction stir welds in Al5083alloy[J].Scripta materialia,2005,53(10):1187-1191.
[133] Zucchi F, Trabanelli G, Grassi V. Pitting and stress corrosion cracking resistance offriction stir welded AA5083[J]. Materials and Corrosion,2001,52(11):853-859.
[134] Sato Y S, Park S H C, Kokawa H. Microstructural factors governing hardness infriction-stir welds of solid-solution-hardened Al alloys[J]. Metallurgical and MaterialsTransactions A,2001,32(12):3033-3042.
[135] Cui G R, Ma Z Y, Li S X. The origin of non-uniform microstructure and its effects onthe mechanical properties of a friction stir processed Al–Mg alloy[J]. Acta Materialia,2009,57(19):5718-5729.
[136] Rodrigues D M, Leitao C, Louro R, et al. High speed friction stir welding ofaluminium alloys[J]. Science and Technology of Welding&Joining,2010,15(8):676-681.
[137] Peel M, Steuwer A, Preuss M, et al. Microstructure, mechanical properties and residualstresses as a function of welding speed in aluminium AA5083friction stir welds[J].Acta Materialia,2003,51(16):4791-4801.
[138] Elangovan K, Balasubramanian V, Babu S. Predicting tensile strength of friction stirwelded AA6061aluminium alloy joints by a mathematical model[J]. Materials&Design,2009,30(1):188-193.
[139] Rajakumar S, Muralidharan C, Balasubramanian V. Establishing empiricalrelationships to predict grain size and tensile strength of friction stir welded AA6061-T6aluminium alloy joints[J]. Transactions of Nonferrous Metals Society ofChina,2010,20(10):1863-1872.
[140] Lakshminarayanan A K, Balasubramanian V, Elangovan K. Effect of weldingprocesses on tensile properties of AA6061aluminium alloy joints[J]. The InternationalJournal of Advanced Manufacturing Technology,2009,40(3-4):286-296.
[141] Lim S, Kim S, Lee C G, et al. Tensile behavior of friction-stri-welded Al6061-T651[J].Metallurgical and Materials Transactions A,2004,35(9):2829-2835.
[142] Cavaliere P, Campanile G, Panella F, et al. Effect of welding parameters on mechanicaland microstructural properties of AA6056joints produced by friction stir welding[J].Journal of Materials Processing Technology,2006,180(1):263-270.
[143] Ren S R, Ma Z Y, Chen L Q. Effect of welding parameters on tensile properties andfracture behavior of friction stir welded Al–Mg–Si alloy[J]. Scripta Materialia,2007,56(1):69-72.
[144] Jung S P, Park T W, Kim Y G. Fatigue strength optimisation of friction stir weldedA6005-T5alloy sheets[J]. Science and Technology of Welding&Joining,2010,15(6):473-478.
[145] Feng A H, Chen D L, Ma Z Y. Microstructure and low-cycle fatigue of afriction-stir-welded6061aluminum alloy[J]. Metallurgical and Materials TransactionsA,2010,41(10):2626-2641.
[146] Moreira P, De Figueiredo M A V, De Castro P. Fatigue behaviour of FSW and MIGweldments for two aluminium alloys[J]. Theoretical and applied fracture mechanics,2007,48(2):169-177.
[147] Ericsson M, Sandstr m R. Influence of welding speed on the fatigue of friction stirwelds, and comparison with MIG and TIG[J]. International Journal of Fatigue,2003,25(12):1379-1387.
[148] Sato Y S, Kokawa H, Enomoto M, et al. Microstructural evolution of6063aluminumduring friction-stir welding[J]. Metallurgical and Materials Transactions A,1999,30(9):2429-2437.
[149] Sato Y S, Kokawa H, Enomoto M, et al. Precipitation sequence in friction stir weld of6063aluminum during aging[J]. Metallurgical and Materials Transactions A,1999,30(12):3125-3130.
[150] Sato Y S, Kokawa H, Ikeda K, et al. Microtexture in the friction-stir weld of analuminum alloy[J]. Metallurgical and Materials Transactions A,2001,32(4):941-948.
[151] Sato Y S, Kokawa H. Distribution of tensile property and microstructure in friction stirweld of6063aluminum [J]. Metallurgical and Materials Transactions A,2001,32(12):3023-3031.
[152] Olea C A W, Roldo L, Dos Santos J F, et al. A sub-structural analysis of friction stirwelded joints in an AA6056Al-alloy in T4and T6temper conditions[J]. MaterialsScience and Engineering: A,2007,454:52-62.
[153] Gallais C, Denquin A, Bréchet Y, et al. Precipitation microstructures in an AA6056aluminium alloy after friction stir welding: characterisation and modelling[J].Materials Science and Engineering: A,2008,496(1):77-89.
[154] Heinz B, Skrotzki B. Characterization of a friction-stir-welded aluminum alloy6013[J].Metallurgical and Materials Transactions B,2002,33(3):489-498.
[155] Lee W B, Yeon Y M, Jung S B. Evaluation of the microstructure and mechanicalproperties of friction stir welded6005aluminum alloy[J]. Materials Science andTechnology,2003,19(11):1513-1518.
[156] Simar A, Brechet Y, De Meester B, et al. Microstructure, local and global mechanicalproperties of friction stir welds in aluminium alloy6005A-T6[J]. Materials Scienceand Engineering: A,2008,486(1):85-95.
[157] Sauvage X, DédéA, Munoz A C, et al. Precipitate stability and recrystallisation in theweld nuggets of friction stir welded Al–Mg–Si and Al–Mg–Sc alloys[J]. MaterialsScience and Engineering: A,2008,491(1):364-371.
[158] Cerri E, Leo P, Wang X, et al. Mechanical properties and microstructural evolution offriction-stir-welded thin sheet aluminum alloys[J]. Metallurgical and MaterialsTransactions A,2011,42(5):1283-1295.
[159] Cabibbo M, McQueen H J, Evangelista E, et al. Microstructure and mechanicalproperty studies of AA6056friction stir welded plate[J]. Materials Science andEngineering: A,2007,460:86-94.
[160] Hamilton C, Dymek S, Blicharski M, et al. Microstructural and flow characteristics offriction stir welded aluminium6061-T6extrusions[J]. Science and Technology ofWelding&Joining,2007,12(8):732-737.
[161] Liu F C, Ma Z Y. Influence of tool dimension and welding parameters onmicrostructure and mechanical properties of friction-stir-welded6061-T651aluminumalloy[J]. Metallurgical and Materials Transactions A,2008,39(10):2378-2388.
[162] Woo W, Choo H, Brown D W, et al. Influence of the Tool Pin and Shoulder onMicrostructure and Natural Aging Kinetics in a Friction-Stir-Processed6061–T6Aluminum Alloy[J]. Metallurgical and Materials Transactions A,2007,38(1):69-76.
[163] Singh R K R, Sharma C, Dwivedi D K, et al. The microstructure and mechanicalproperties of friction stir welded Al–Zn–Mg alloy in as welded and heat treatedconditions[J]. Materials&Design,2011,32(2):682-687.
[164] Yeni C, Sayer S, Pakdil M. Comparison of mechanical and microstructural behavior ofTIG, MIG and friction stir welded7075aluminum alloy[J]. Kovove Mater,2009,47:341-347.
[165] Ceschini L, Boromei I, Minak G, et al. Effect of friction stir welding on microstructure,tensile and fatigue properties of the AA7005/10vol.%Al2O3pcomposite[J].Composites science and technology,2007,67(3):605-615.
[166] Sharma C, Dwivedi D K, Kumar P. Effect of welding parameters on microstructureand mechanical properties of friction stir welded joints of AA7039aluminum alloy[J].Materials&Design,2012,36:379-390.
[167] Jata K V, Sankaran K K, Ruschau J J. Friction-stir welding effects on microstructureand fatigue of aluminum alloy7050-T7451[J]. Metallurgical and MaterialsTransactions A,2000,31(9):2181-2192.
[168] Ericsson M, Sandstr m R. Influence of welding speed on the fatigue of friction stirwelds, and comparison with MIG and TIG[J]. International Journal of Fatigue,2003,25(12):1379-1387.
[169] Dudzik K. Stress corrosion cracking of7020aluminium alloy jointed by differentwelding methods[J]. Journal of KONES,2010,17:143-147.
[170] Lumsden J B, Mahoney M W, Rhodes C G, et al. Corrosion behavior offriction-stir-welded AA7050-T7651[J]. Corrosion,2003,59(3):212-219.
[171] Paglia C S, Buchheit R G. The time–temperature–corrosion susceptibility in a7050-T7451friction stir weld[J]. Materials Science and Engineering: A,2008,492(1):250-254.
[172] Sharma C, Dwivedi D K, Kumar P. Effect of post weld heat treatments onmicrostructure and mechanical properties of friction stir welded joints of Al–Zn–Mgalloy AA7039[J]. Materials&Design,2013,43:134-143.
[173] Fuller C B, Mahoney M W, Calabrese M, et al. Evolution of microstructure andmechanical properties in naturally aged7050and7075Al friction stir welds[J].Materials Science and Engineering: A,2010,527(9):2233-2240.
[174] Su J Q, Nelson T W, Mishra R, et al. Microstructural investigation of friction stirwelded7050-T651aluminium[J]. Acta Materialia,2003,51(3):713-729.
[175] Dumont M, Steuwer A, Deschamps A, et al. Microstructure mapping in friction stirwelds of7449aluminium alloy using SAXS[J]. Acta materialia,2006,54(18):4793-4801.
[176]刘杰,杨景宏,韩凤武,等.厚板铝合金搅拌摩擦焊匙孔补焊接头组织与性能[J].材料工程,2012(7):29-33.
[177]王国庆,赵刚,郝云飞,等.2219铝合金搅拌摩擦焊缝匙孔形缺陷修补技术[J].宇航材料工艺,2012,42(3):24-28.
[178]黄永宪,韩冰,吕世雄,等.基于固态连接原理的填充式搅拌摩擦焊匙孔修复技术[J].焊接学报,2012,33(3):5-8.
[179]李博,沈以赴,胡伟叶.伸缩式搅拌头厚铝板搅拌摩擦焊缺陷及其补焊工艺[J].中国有色金属学报,2012,22(1):62-71.
[180] Vedani M, Angella G, Bassani P, et al. DSC analysis of strengthening precipitates inultrafine Al–Mg–Si alloys[J]. Journal of Thermal Analysis and Calorimetry,2007,87(1):277-284.
[181] Birol Y. DSC analysis of the precipitation reaction in AA6005alloy[J]. Journal ofthermal analysis and calorimetry,2008,93(3):977-981.
[182] Zuo J M, Mabon J C. Web-based electron microscopy application software:Web-EMAPS[J]. Microscopy and Microanalysis,2004,10(S02):1000-1001.
[183] http://www.gatan.com/
[184] Dutta I, Allen S M. A calorimetric study of precipitation in commercial aluminiumalloy6061[J]. Journal of Materials Science Letters,1991,10(6):323-326.
[185] Yang W, Wang M, Sheng X, et al. Precipitate characteristics and selected areadiffraction patterns of the β′and Q′precipitates in Al–Mg–Si–Cu alloys[J].Philosophical Magazine Letters,2011,91(2):150-160.
[193] Sato Y S, Urata M, Kokawa H, et al. Retention of fine grained microstructure of equalchannel angular pressed aluminum alloy1050by friction stir welding[J]. ScriptaMaterialia,2001,45(1):109-114.
[195] Rhodes C G, Mahoney M W, Bingel W H, et al. Fine-grain evolution in friction-stirprocessed7050aluminum[J]. Scripta Materialia,2003,48(10):1451-1455.
[196] Arora A, Zhang Z, De A, et al. Strains and strain rates during friction stir welding[J].Scripta Materialia,2009,61(9):863-866.
[197] Hassan Kh A A, Wynne B P, Prangnell P B. Microstructure, residual stress distributionand mechanical properties of friction-stir AA6061aluminium alloyweldments[C]//Proceedings of the National Seminar on Non-Destructive Evaluation.2006:1-19.
[198] Militzer M, Sun W P, Jonas J J. Modelling the effect of deformation-induced vacancieson segregation and precipitation[J]. Acta metallurgica et materialia,1994,42(1):133-141.
[199] Chen Y C, Bakavos D, Gholinia A, et al. HAZ development and accelerated post-weldnatural ageing in ultrasonic spot welding aluminium6111-T4automotive sheet[J].Acta Materialia,2012,60(6):2816-2828.
[200] zbilen S, Flower H M. Zirconium-vacancy binding and its influence on S′precipitation in an Al–Cu–Mg alloy[J]. Acta Metallurgica,1989,37(11):2993-3000.
[201] Perry A J. Solute-vacancy interaction energies and the effect of0.009at.%Mg on theageing kinetics of an Al-4.01at.%Zn alloy[J]. Acta Metallurgica,1966,14(10):1143-1156.
[202] Raman K S, Das E S D, Vasu K I. Clustering and solute-vacancy binding energies inAl-4.4%Zn alloy with0.01%ternary additions[J]. Journal of Materials Science,1971,6(11):1367-1378.
[203] Perry A J. Copper clustering and vacancy loss during the quenching ofaluminium-copper alloys[J]. Acta Metallurgica,1966,14(3):305-312.
[204] Khandkar M Z H, Khan J A, Reynolds A P. Prediction of temperature distribution andthermal history during friction stir welding: input torque based model[J]. Science andTechnology of Welding&Joining,2003,8(3):165-174.
[205]田容章,王祝堂.铝合金及其加工手册[M].长沙：中南大学出版社，2000.
[206] Shercliff H R, Ashby M F. A process model for age hardening of aluminium alloys [J].Acta Metallurgica et Materialia,1990,38(10):1789-1812.
[207] Myhr O R, Grong. Process modelling applied to6082-T6aluminium weldments [J].Acta Metallurgica et Materialia,1991,39(11):2693-2708.
[208] Shercliff H R, Russell M J, Taylor A, et al. Microstructural modelling in friction stirwelding of2000series aluminium alloys[J]. Mecanique&Industries,2005,6(01):25-35.
[209] Robson J D, Kamp N, Sullivan A. Microstructural modelling for friction stir weldingof aluminium alloys[J]. Materials and manufacturing processes,2007,22(4):450-456.
[210] Myhr O R, Grong. Modelling of non-isothermal transformations in alloys containinga particle distribution[J]. Acta Materialia,2000,48(7):1605-1615.
[211] Wagner R, Kampmann R. Materials science and technology–a comprehensivetreatment [M]. Weinhem: Wiley-VCH,1991.
[212] Hersent E, Driver J H, Piot D, et al. Integrated modelling of precipitation duringfriction stir welding of2024-T3aluminium alloy[J]. Materials Science and Technology,2010,26(11):1345-1352.
[213] Simar A, Bréchet Y, De Meester B, et al. Integrated modeling of friction stir welding of6xxx series Al alloys: Process, microstructure and properties[J]. Progress in MaterialsScience,2012,57(1):95-183.
[214] Gallais C, Denquin A, Bréchet Y, et al. Precipitation microstructures in an AA6056aluminium alloy after friction stir welding: characterisation and modelling[J].Materials Science and Engineering: A,2008,496(1):77-89.
[215] Kamp N, Sullivan A, Robson J D. Modelling of friction stir welding of7xxxaluminium alloys[J]. Materials Science and Engineering: A,2007,466(1):246-255.
[216]冯端.金属物理学：相变.第二卷[M].北京：科学出版社,1990.
[217] Samaras S N. Modelling of microstructure evolution during precipitation processes: apopulation balance approach of the KWN model[J]. Modelling and Simulation inMaterials Science and Engineering,2006,14(8):1271-1292.
[218] Callais C. Modelling the relationship between process parameters, microstructuralevolutions and mechanical behaviour in a friction stir weld6xxx aluminiumalloy[C]//Proceedings of5th International FSW symposium, Metz, France,2004.
[219] Esmaeili S, Lloyd D J, Poole W J. A yield strength model for the Al-Mg-Si-Cu alloyAA6111[J]. Acta Materialia,2003,51(8):2243-2257.
[220] Bardel D, Perez M, Nelias D, et al. Coupled precipitation and yield strength modellingfor non-isothermal treatments of a6061aluminium alloy[J]. Acta Materialia,2014,62:129-140.
[221] Grong, Shercliff H R. Microstructural modelling in metals processing[J]. Progress inMaterials Science,2002,47(2):163-282.