铝合金点焊电极的延寿技术研究
|
摘要
铝合金的电阻点焊是汽车车身自动化生产中最重要的焊接工艺方法,但是铝合金电阻点焊中存在的一个主要问题就是电极过快烧损,引起电极的频繁更换,影响生产效率。因此研究铝合金点焊电极的延寿技术至关重要。
本文通过对铝合金点焊电极烧损失效机理的研究发现,点焊时电极与铝合金工件接触面间的不均匀点接触造成通电瞬间局部小爆炸而使电极端面局部区域产生塑性变形,这种局部的塑性变形反过来又加剧了电极与工件接触面间的不均匀点接触,由不均匀点接触引起的局部小爆炸和铜铝合金化交互作用,使电极失效速度加快。因此,铝合金点焊电极延寿技术研究的基本原则,就是要减轻电极与铝合金工件接触面间的铜铝合金化以及减少不均匀点接触造成的局部小爆炸。本文从电极表面和铝合金工件表面两种角度出发,寻找制备涂层材料,以延长电极的使用寿命。
从电极表面考虑,我们探索性地利用点焊时产生的电阻热和加压作用,成功地在锆铬青铜电极表面原位合成了Cu-Ti-B复合电极涂层。通过对复合涂层组织、成分的分析,我们发现其中含有条状以及粒状的TiBB具有很好的热强性,点焊时可以增强涂层基体的强度,减少电极端面局部小爆炸引起的塑性变形。故用Cu-Ti-B复合涂层电极点焊铝合金是可以延长电极使用寿命的,以后还要做进一步的研究。
从铝合金工件表面考虑,在铝合金表面涂敷矿物油和B的混合物,点焊时一方面可以机械地隔离铜电极中的铜与铝的接触,降低电极与铝合金工件接触面间的温度,从而减轻铜铝合金化,另一方面还可以减少不均匀点接触造成的局部小爆炸。因而铝合金表面涂敷矿物油和BBC的混合物时,电极烧损程度较轻,电极使用寿命得到了延长。
Resistance spot welding of aluminum alloy is the most important welding technique in the automatic production of car body. However, there is a problem that the ignition loss of the electrode is too fast, which leads to frequent replacement, so production efficiency is reduced and the cost increases. Consequently, the technique of prolonging the electrode life of aluminum alloy spot welding is of reality significance.
The research of the mechanism for the ignition loss of the electrode in spot welding of aluminum alloy shows that, plastic deformation is generated in part of the electrode surface by blasting right after the electrification, which is caused by the non-uniform point contact between electrodes and aluminum alloy work-pieces. The plastic deformation accelerates the non-uniform point contact. Blasting caused by the non-uniform point contact in part of the electrode surface leads to the ignition loss, which interacts with Cu-Al synthesis, makes the electrode worse. Hence, the life prolonging technique is to restrain Cu-Al synthesis at the interfaces of electrodes and aluminum alloy work-pieces and reduce blasting caused by the non-uniform point contact. From the point of the electrode surface and the aluminum alloy work piece surface, coating materials are sought and prepared to prolong the electrode life. For the electrode,compound electrode coating of Cu-Ti-B is successfully synthesized in situ at the Zr-Cr-Cu electrode surface by resistance heat and pressure while spot welding. Structure and component analysis show that it contains TiB
strips and grainy with good heat resistance which can intensify the strength of coating base and reduce the plastic deformation generated in part of the electrode surface by blasting right after the electrification. So it is feasible to prolong the electrode life of aluminum alloy spot welding by the Cu-Ti-B compound coating of the electrode. Further research will be grasped.
For the aluminum alloy,coating mixture of mineral oil and B_4C on the work-piece can reduce the contact of Cu and Al, and the temperature at the interfaces of electrodes and aluminum alloy work-pieces, which restrain Cu-Al synthesis on one hand. On the other hand mineral oil and B_4BC can reduce the non-uniform point contact and relieve blasting in part of the electrode surface. Hence, the spot welding result of aluminum alloy with the coating mixture of mineral oil and BBC is better, and the electrode life of aluminum alloy spot welding is prolonged.
本文通过对铝合金点焊电极烧损失效机理的研究发现,点焊时电极与铝合金工件接触面间的不均匀点接触造成通电瞬间局部小爆炸而使电极端面局部区域产生塑性变形,这种局部的塑性变形反过来又加剧了电极与工件接触面间的不均匀点接触,由不均匀点接触引起的局部小爆炸和铜铝合金化交互作用,使电极失效速度加快。因此,铝合金点焊电极延寿技术研究的基本原则,就是要减轻电极与铝合金工件接触面间的铜铝合金化以及减少不均匀点接触造成的局部小爆炸。本文从电极表面和铝合金工件表面两种角度出发,寻找制备涂层材料,以延长电极的使用寿命。
从电极表面考虑,我们探索性地利用点焊时产生的电阻热和加压作用,成功地在锆铬青铜电极表面原位合成了Cu-Ti-B复合电极涂层。通过对复合涂层组织、成分的分析,我们发现其中含有条状以及粒状的TiBB具有很好的热强性,点焊时可以增强涂层基体的强度,减少电极端面局部小爆炸引起的塑性变形。故用Cu-Ti-B复合涂层电极点焊铝合金是可以延长电极使用寿命的,以后还要做进一步的研究。
从铝合金工件表面考虑,在铝合金表面涂敷矿物油和B的混合物,点焊时一方面可以机械地隔离铜电极中的铜与铝的接触,降低电极与铝合金工件接触面间的温度,从而减轻铜铝合金化,另一方面还可以减少不均匀点接触造成的局部小爆炸。因而铝合金表面涂敷矿物油和BBC的混合物时,电极烧损程度较轻,电极使用寿命得到了延长。
Resistance spot welding of aluminum alloy is the most important welding technique in the automatic production of car body. However, there is a problem that the ignition loss of the electrode is too fast, which leads to frequent replacement, so production efficiency is reduced and the cost increases. Consequently, the technique of prolonging the electrode life of aluminum alloy spot welding is of reality significance.
The research of the mechanism for the ignition loss of the electrode in spot welding of aluminum alloy shows that, plastic deformation is generated in part of the electrode surface by blasting right after the electrification, which is caused by the non-uniform point contact between electrodes and aluminum alloy work-pieces. The plastic deformation accelerates the non-uniform point contact. Blasting caused by the non-uniform point contact in part of the electrode surface leads to the ignition loss, which interacts with Cu-Al synthesis, makes the electrode worse. Hence, the life prolonging technique is to restrain Cu-Al synthesis at the interfaces of electrodes and aluminum alloy work-pieces and reduce blasting caused by the non-uniform point contact. From the point of the electrode surface and the aluminum alloy work piece surface, coating materials are sought and prepared to prolong the electrode life. For the electrode,compound electrode coating of Cu-Ti-B is successfully synthesized in situ at the Zr-Cr-Cu electrode surface by resistance heat and pressure while spot welding. Structure and component analysis show that it contains TiB
strips and grainy with good heat resistance which can intensify the strength of coating base and reduce the plastic deformation generated in part of the electrode surface by blasting right after the electrification. So it is feasible to prolong the electrode life of aluminum alloy spot welding by the Cu-Ti-B compound coating of the electrode. Further research will be grasped.
For the aluminum alloy,coating mixture of mineral oil and B_4C on the work-piece can reduce the contact of Cu and Al, and the temperature at the interfaces of electrodes and aluminum alloy work-pieces, which restrain Cu-Al synthesis on one hand. On the other hand mineral oil and B_4BC can reduce the non-uniform point contact and relieve blasting in part of the electrode surface. Hence, the spot welding result of aluminum alloy with the coating mixture of mineral oil and BBC is better, and the electrode life of aluminum alloy spot welding is prolonged.
引文
[1]曲晓峰.轻质材料在汽车上的应用[J].中国机电行业,2002,7:37~38.
[2]管学理.汽车节能(节油)技术发展动态[J].水利电力科技,1995,22(2): 40~45
[3]A S Warren Banbury.The Future of Applying Aluminum Alloy to Automobile[J].ALUMINIUM,2003,Vol.6711:1078~1080.
[4]陈仕奇.铜基粉末及材料研究新进展[J].粉末冶金工业,2002,5:32~33.
[5]马苗生,黄福样.铜基引线框架材料的研究与发展[J].功能材料,2002,6:1~4.
[6]温宏权,毛协民,戚飞鹏.高强度高导电性铜合金研究现状及展望[J].功能材料,1995,12:553~556.
[7]郑强,陈康华等.浅谈铝合金的焊接[J].铝加工,2003,152:49~50.
[8]刘德宝,崔春翔.高强度高导电铜基复合材料制备技术回顾与展望[J].天津理 工学院学报,2002,10:25~29.
[9]中国机械工程学会焊接学会.焊接手册(第 1 卷)-焊接方法及设备[M].北京:机械工业出版社,1992.
[10]中国机械工程学会焊接学会.焊接手册(第 2 卷)-材料的焊接[M].北京:机械工业出版社,1992.
[11](美)L F 蒙多尔福(著),王祝堂等(译).铝合金的组织与性能[M].北京:冶金工业出版社,1988.
[12]R H Thorton,A R Krause,et al..The aluminum spot welding[J].Welding Journal,1996,75(3):101~108.
[13]Ulrich Dilthey,et al..Metallographic investigations into wear processes of electrodes during the resistance spot welding of aluminum[J].Welding & Cutting,1998,1:34~40.
[14]中国机械工程学会焊接学会电阻焊(Ш)委员会.电阻焊理论与实践[M].北京:机械工业出版社,1994.
[15]Waller,D N.Head movement as a means of resistance spot welding quality control[J].Metal construction,1964,11(3):118~122.
[16]Johnson K L,Needham.J C.New design of resistance spot welding machine for quality control[J].Welding Journal,1972,51(3):122~131.
[17]Greitmann M J,et al..Quality assurance by process analysis in the resistance spot welding of aluminum[J].Welding and Cutting,1996,48(1):E2~E4.
[18]李桂中等.低碳钢点焊动态过程的模拟化控制[J].焊接学报,1995,16(2):75~81.
[19]赵熹华等.汽车点焊工艺选择及接头质量预测人工智能化研究[J].汽车技术,1998,8:26~29.
[20]K Matsuyama.Recent developments and trends in quality control technology for resistance welding[J].Welding International,1996,10(9):743~747.
[21]S Bhattacharya,D R Andrews.Significance of Dynamic Resistance Curves in Theory and Practice of Spot Welding[J].Welding and Metal Fabrication,1987,42(2):296~299.
[22]程方杰.铝合金点焊中的接触电阻与电极烧损问题的研究[D].天津:天津大学,2001.
[23]R F Ashton,D D Rager.An arc-cleaning approach for resistance welding aluminum[J].Welding Journal,1976,55(9):750~757.
[24]Juarez Islas Ja,et al..J Mater[J].Sci Lett,1992,11(6):1104.
[25]Bebkj,et al..J Appl[J].Phys,1978.49:6031.
[26]Verhoeben J D,et al..J Mater[J].Sci.,1989,24:1748.
[27]曾松岩等.一种新型的制备金属基复合材料的方法[J].宇航材料工艺,1995,25(5):27.
[28]蒋建清等.自生复合材料及其进展[J].材料科学与工程,1993,11(1):38.
[29]徐梅,董仕杰等.点焊电极失效的研究进展[J].热加工工艺,2003,2:47~49.
[30]傅正义,王为民,王浩等.TiBB2B-xAl复合材料的结构形成分析[J].金属学报,1994,30(8):B373~378.
[31]傅正义,袁润章,Munir Z A.TiBB2B-xA1 复合体系的SHS合成过程研究[J].金属学报,1993,29(7):B330~334.
[32]赵金龙,董国峰,高钦.(A1B2BOB3B+TiBB2B)/A1 复合陶瓷与A1 连接的研究[J].大连理工大学学报,1997,37(6):742~744.
[33]Monty Squire.TiBB2B ceramic:New wear-resistant coating[J].Advanced Materials & Processes,1990,137(4):117.
[34]陈敬超,孙家林,孙可伟.40Cr 钢表面改性覆层的磨料磨损研究[J].理化检验——物理分册,1998,34(7):3~5.
[35]Wang Xibao,Liang Yong,Yang Songlan.Formation of TiBB2B whiskers in laser clad Fe-Ti-B coatings[J].Surface and Coatings Technology,2001,137:209~216.
[36]杨松岚,王福会,冯钟潮等.激光熔覆 Fe-Ti-B 复相涂层的组织研究[J].金属热处理,1999,7(3):20~23.
[37]孙荣禄,杨德庄,董尚利等.钛合金表面 NiCrBSi 激光熔覆层的组织与耐磨性研究[J].应用激光,2000,20(5):261~263(260).
[38]孙荣禄,郭立新,董尚利等.钛合金表面激光熔覆 NiCrBSiC 合金涂层的微观组织[J].佳木斯大学学报(自然科学版),2000,18(3):214~218.
[39]孙荣禄,杨德庄,郭立新等.激光工艺参数对钛合金表面 NiCrBSi 合金熔覆层组织及硬度的影响[J].光学技术,2001,27(1):3436(38).
[40]佐佐木雄贞,遠藤纮,本田忠史等.复合型制振钢板の特性と利用技术[J].铁と钢,1978,64(8):124~133.
[41]Smid I,Kny E.Evaluation of binder phases for hard metal systems based on TiBB2B [J].Inter.J.Refractory and Hard Mater,1988,7(3):135~138.
[42]徐梅,董仕杰等.点焊电极失效的研究进展[J],热加工工艺,2003,2:47~49.
[43]程方杰,廉金瑞等.铝合金电阻点焊电极烧损机理研究[J].兵器材料科学与工程,2003,2:26~28.
[44]杨继尚,廉金瑞,李宝清.铝合金滞留点焊时电极的不对称烧损研究[J].焊接技术,2000,29(5):32~33.
[45]吴志生,单平,胡绳荪等.铝合金点焊过程的铜铝合金化研究[J].中国机械工程,2003,14(16):1433~1434.
[46]沃丁柱,李顺林,王兴业等.复合材料大全[M].北京:化学工业出版社,2000,8:128~129.
[47]耶菲莫夫 А И,别洛鲁科娃 Д П,瓦西里科娃И В等.无机化合物性质手册[M].西安:陕西科学技术出版社,1987,200.
[48]Wang Xibao.The metallurgical behavior of BB4BC in the iron-based surfacing alloy during PTA powder surfacing[J].Applied Surface Science,2005,252:2021~2028.
[49]Wang Xibao.The composite Fe-Ti-B-C coating by PTA process[J].Surface and coatings technology.2005,vol.192(2-3):257~262.
[50]王惜宝.Fe-Ti-B激光熔敷层中TiBB2B晶须的原位合成[J].金属学报,2003,39(2):193~198.
[51]刘尧铭.点焊电极材料及结构设计[J].机械工程学报,2000,11(2):25~26.
[52]李存剑.新型电阻焊电极[J].焊接,2003,6(2):45~48.
[53]黄勇,樊丁,樊清华.铝合金点焊的试验研究[J].焊接,2004,10(3):52~54.
[54]程方杰,单平,廉金瑞等.铝合金连续点焊时电极烧损与焊点表面质量的变化规律[J].天津大学学报,2003,36(6):28~32.
[55]曾鸿志.铝合金点焊电极寿命的研究[D].天津:天津大学,2001.
[2]管学理.汽车节能(节油)技术发展动态[J].水利电力科技,1995,22(2): 40~45
[3]A S Warren Banbury.The Future of Applying Aluminum Alloy to Automobile[J].ALUMINIUM,2003,Vol.6711:1078~1080.
[4]陈仕奇.铜基粉末及材料研究新进展[J].粉末冶金工业,2002,5:32~33.
[5]马苗生,黄福样.铜基引线框架材料的研究与发展[J].功能材料,2002,6:1~4.
[6]温宏权,毛协民,戚飞鹏.高强度高导电性铜合金研究现状及展望[J].功能材料,1995,12:553~556.
[7]郑强,陈康华等.浅谈铝合金的焊接[J].铝加工,2003,152:49~50.
[8]刘德宝,崔春翔.高强度高导电铜基复合材料制备技术回顾与展望[J].天津理 工学院学报,2002,10:25~29.
[9]中国机械工程学会焊接学会.焊接手册(第 1 卷)-焊接方法及设备[M].北京:机械工业出版社,1992.
[10]中国机械工程学会焊接学会.焊接手册(第 2 卷)-材料的焊接[M].北京:机械工业出版社,1992.
[11](美)L F 蒙多尔福(著),王祝堂等(译).铝合金的组织与性能[M].北京:冶金工业出版社,1988.
[12]R H Thorton,A R Krause,et al..The aluminum spot welding[J].Welding Journal,1996,75(3):101~108.
[13]Ulrich Dilthey,et al..Metallographic investigations into wear processes of electrodes during the resistance spot welding of aluminum[J].Welding & Cutting,1998,1:34~40.
[14]中国机械工程学会焊接学会电阻焊(Ш)委员会.电阻焊理论与实践[M].北京:机械工业出版社,1994.
[15]Waller,D N.Head movement as a means of resistance spot welding quality control[J].Metal construction,1964,11(3):118~122.
[16]Johnson K L,Needham.J C.New design of resistance spot welding machine for quality control[J].Welding Journal,1972,51(3):122~131.
[17]Greitmann M J,et al..Quality assurance by process analysis in the resistance spot welding of aluminum[J].Welding and Cutting,1996,48(1):E2~E4.
[18]李桂中等.低碳钢点焊动态过程的模拟化控制[J].焊接学报,1995,16(2):75~81.
[19]赵熹华等.汽车点焊工艺选择及接头质量预测人工智能化研究[J].汽车技术,1998,8:26~29.
[20]K Matsuyama.Recent developments and trends in quality control technology for resistance welding[J].Welding International,1996,10(9):743~747.
[21]S Bhattacharya,D R Andrews.Significance of Dynamic Resistance Curves in Theory and Practice of Spot Welding[J].Welding and Metal Fabrication,1987,42(2):296~299.
[22]程方杰.铝合金点焊中的接触电阻与电极烧损问题的研究[D].天津:天津大学,2001.
[23]R F Ashton,D D Rager.An arc-cleaning approach for resistance welding aluminum[J].Welding Journal,1976,55(9):750~757.
[24]Juarez Islas Ja,et al..J Mater[J].Sci Lett,1992,11(6):1104.
[25]Bebkj,et al..J Appl[J].Phys,1978.49:6031.
[26]Verhoeben J D,et al..J Mater[J].Sci.,1989,24:1748.
[27]曾松岩等.一种新型的制备金属基复合材料的方法[J].宇航材料工艺,1995,25(5):27.
[28]蒋建清等.自生复合材料及其进展[J].材料科学与工程,1993,11(1):38.
[29]徐梅,董仕杰等.点焊电极失效的研究进展[J].热加工工艺,2003,2:47~49.
[30]傅正义,王为民,王浩等.TiBB2B-xAl复合材料的结构形成分析[J].金属学报,1994,30(8):B373~378.
[31]傅正义,袁润章,Munir Z A.TiBB2B-xA1 复合体系的SHS合成过程研究[J].金属学报,1993,29(7):B330~334.
[32]赵金龙,董国峰,高钦.(A1B2BOB3B+TiBB2B)/A1 复合陶瓷与A1 连接的研究[J].大连理工大学学报,1997,37(6):742~744.
[33]Monty Squire.TiBB2B ceramic:New wear-resistant coating[J].Advanced Materials & Processes,1990,137(4):117.
[34]陈敬超,孙家林,孙可伟.40Cr 钢表面改性覆层的磨料磨损研究[J].理化检验——物理分册,1998,34(7):3~5.
[35]Wang Xibao,Liang Yong,Yang Songlan.Formation of TiBB2B whiskers in laser clad Fe-Ti-B coatings[J].Surface and Coatings Technology,2001,137:209~216.
[36]杨松岚,王福会,冯钟潮等.激光熔覆 Fe-Ti-B 复相涂层的组织研究[J].金属热处理,1999,7(3):20~23.
[37]孙荣禄,杨德庄,董尚利等.钛合金表面 NiCrBSi 激光熔覆层的组织与耐磨性研究[J].应用激光,2000,20(5):261~263(260).
[38]孙荣禄,郭立新,董尚利等.钛合金表面激光熔覆 NiCrBSiC 合金涂层的微观组织[J].佳木斯大学学报(自然科学版),2000,18(3):214~218.
[39]孙荣禄,杨德庄,郭立新等.激光工艺参数对钛合金表面 NiCrBSi 合金熔覆层组织及硬度的影响[J].光学技术,2001,27(1):3436(38).
[40]佐佐木雄贞,遠藤纮,本田忠史等.复合型制振钢板の特性と利用技术[J].铁と钢,1978,64(8):124~133.
[41]Smid I,Kny E.Evaluation of binder phases for hard metal systems based on TiBB2B [J].Inter.J.Refractory and Hard Mater,1988,7(3):135~138.
[42]徐梅,董仕杰等.点焊电极失效的研究进展[J],热加工工艺,2003,2:47~49.
[43]程方杰,廉金瑞等.铝合金电阻点焊电极烧损机理研究[J].兵器材料科学与工程,2003,2:26~28.
[44]杨继尚,廉金瑞,李宝清.铝合金滞留点焊时电极的不对称烧损研究[J].焊接技术,2000,29(5):32~33.
[45]吴志生,单平,胡绳荪等.铝合金点焊过程的铜铝合金化研究[J].中国机械工程,2003,14(16):1433~1434.
[46]沃丁柱,李顺林,王兴业等.复合材料大全[M].北京:化学工业出版社,2000,8:128~129.
[47]耶菲莫夫 А И,别洛鲁科娃 Д П,瓦西里科娃И В等.无机化合物性质手册[M].西安:陕西科学技术出版社,1987,200.
[48]Wang Xibao.The metallurgical behavior of BB4BC in the iron-based surfacing alloy during PTA powder surfacing[J].Applied Surface Science,2005,252:2021~2028.
[49]Wang Xibao.The composite Fe-Ti-B-C coating by PTA process[J].Surface and coatings technology.2005,vol.192(2-3):257~262.
[50]王惜宝.Fe-Ti-B激光熔敷层中TiBB2B晶须的原位合成[J].金属学报,2003,39(2):193~198.
[51]刘尧铭.点焊电极材料及结构设计[J].机械工程学报,2000,11(2):25~26.
[52]李存剑.新型电阻焊电极[J].焊接,2003,6(2):45~48.
[53]黄勇,樊丁,樊清华.铝合金点焊的试验研究[J].焊接,2004,10(3):52~54.
[54]程方杰,单平,廉金瑞等.铝合金连续点焊时电极烧损与焊点表面质量的变化规律[J].天津大学学报,2003,36(6):28~32.
[55]曾鸿志.铝合金点焊电极寿命的研究[D].天津:天津大学,2001.