热处理制度对汽车用TC6钛合金组织及性能的影响

Effect of heat treatment on microstructure and properties of TC6 titanium alloy

采用四种不同热处理制度对汽车用TC6钛合金棒材进行了等温退火试验,并进行了试样显微组织、耐磨损性能和耐腐蚀性能测试与分析。结果表明,采用“870℃保温1.5 h,炉冷至600℃保温2 h,空冷”热处理制度(1^(#)试样)时,合金的耐磨损和耐腐蚀性能最差;采用“900℃保温1.5 h,炉冷至600℃保温2 h,空冷”热处理制度(2^(#)试样)时,合金的耐磨损和耐腐蚀性能最佳;采用“920℃保温1.5 h,炉冷至600℃保温2 h,空冷”(3^(#)试样)和“900℃保温1.5 h,炉冷至620℃保温2 h,空冷”(4^(#)试样)时,合金试样的腐蚀电位和耐腐蚀性能介于上述二者之间。与1^(#)试样相比,2^(#)试样的磨损体积减小8×10^(−3)mm ^(3)、腐蚀电位正移53 mV。

TC6 titanium alloy bars were annealed by four different heat treatment processes.The microstructure,wear resistance and corrosion resistance of the samples were tested and analyzed.The results show that under the heat treatment at 870℃for 1.5 h,furnace cooling to 600℃and insulation for 2 h followed by air cooling,the wear resistance and corrosion resistance of the alloy(sample 1^(#))are the worst.The sample under the heat treatment at 900℃for 1.5 h,furnace cooling to 600℃and insulation for 2 h followed by air cooling shows the best wear resistance and corrosion resistance(sample 2^(#)).The corrosion potential and corrosion resistance of the samples respectively under the heat treatment processes of 920℃for 1.5 h furnace cooling to 600℃and insulation for 2 h air cooling(sample 3^(#)),and 900℃for 1.5 h furnace cooling to 620℃and insulation for 2 h air cooling(sample 4^(#)),are between those of the sample 1^(#)and sample 2^(#).Compared with sample 1^(#),the wear volume of sample 2^(#) decreases by 8×10^(−3 )mm ^(3),and the corrosion potential shifts by+53 mV.