TiB_2-TiC复相涂层点焊电极焊接镀锌钢板失效过程分析  

Failure analysis of electrodes coated with TiB_2-TiC composite during spot-welding of galvanized steel plates

作　　者：刘琪[1] 罗平[1] 董仕节[1] 杨李安卓 孙世烜[2] 郑重[1] 

机构地区：[1]湖北工业大学湖北省绿色轻工材料重点实验室,湖北武汉430068 [2]首都航天机械公司,北京100076

出　　处：《材料热处理学报》2015年第8期198-202,共5页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51375150;51205114)

摘　　要：为了提高点焊电极焊接镀锌钢板时的使用寿命,复相结构的Ti B2-Ti C涂层电极在点焊镀锌钢板过程中被采用。文中采用SEM、XRD分析手段分析了Ti B2-Ti C复相涂层电极点焊镀锌钢板时的失效过程。分析结果说明,由于受机械力和焊接热等诸多因素的影响,使原本完整的Ti B2-Ti C复相涂层产生裂纹。裂纹扩展交织成网状,增加了Ti B2-Ti C复相涂层电极与钢板镀层之间的合金化程度。由于局部区域合金化的影响,使得涂层成片脱落,导致了更深程度的合金化,促使Ti B2-Ti C复相涂层电极失效。Ti B2-Ti C复相涂层电极失效,是合金化与塑性变形共同的结果。A TiB2-TiC composite coating on electrodes was investigated for improving the lifespan of the electrodes used for spot welding of galvanized steel plates. The failure process of the coated electrodes was analyzed by means of scanning electron microscopy, energy- dispersive X-ray spectrometer analysis, and X-ray diffraction. The results show that under the effects of mechanical force and heating, a network of cracks occurs in the coating, which facilitates the alloying between copper from the electrode and the zinc coating of the galvanized steel plates. This local alloying causes the coating to peel off in pieces, further exposing the electrode to alloying until its eventual failure. The failure of TiB2-TIC composite-coated electrodes is thereby the result of both alloying and plastic deformation.

关 键 词：涂层电极 碳化钛-硼化钛 电阻点焊 失效分析 

分 类 号：TG174.45[金属学及工艺—金属表面处理]