摘要
目的细化Cu Cr50合金的Cr相组织,提高组织均匀性。方法采用Nd：YAG脉冲激光器对Cu Cr50合金进行表面处理,并对激光处理后合金的显微组织（表面组织和截面组织）、导电性能、显微硬度、耐磨性等进行测试与分析。结果工艺优化后得到的实验参数为：激光功率500 W,峰值5.0 k W,扫描速度4 mm/s,激光频率6 Hz,激光脉宽5 ms,离焦量为＋4 mm。在优化的工艺条件下,Cu Cr50合金经激光表面处理后,形成了致密的重熔层,Cr相的晶粒得到明显细化,合金的组织均匀性提高,表面孔洞减少。合金重熔层中的相组成未发生变化,合金的导电性略微降低,但仍保持了Cu Cr50合金优良的导电性能。重熔层显微硬度（425-540HV）明显提高,最高硬度为540HV,是基体显微硬度（约240HV）的2.25倍。重熔层的摩擦系数（0.3）远低于原始Cu Cr50合金（0.45）,重熔层的损失质量（0.15 mg）远小于原始Cu Cr50合金的损失质量（0.6 mg）,合金的耐磨性有明显的提高。结论 Cu Cr50合金在优化的工艺参数条件下进行激光表面处理,能够细化Cr相组织和提高整个合金的组织均匀性,提高合金的显微硬度与耐磨性能。
Objective To refine the Cr phase structure of CuCr50 and improve the uniformity of the microstructure. Me- thods CuCrS0 alloys were treated by Nd：YAG pulsed laser, and the microstructure （surface microstructure and cross-section mi- crostructure）, phase, electrical conductivity, microhardness and wear resistance of the alloy were investigated and analyzed after the laser treatment. Results Experimental parameters of process optimization were： laser power 500 W, peak 5.0 kW, scanning speed 4 mm/s, laser frequency 6 Hz, laser pulsed width 5 ms, defocus amount ＋4 mm. Under the optimized process conditions, dense remelting layer was formed, the size of Cr particles was significantly reduced, the structural homogeneity was improved, the hole was reduced after treatment; The phase composition of the remelting layer were not changed, the electrical conductivity was slightly decreased, but the remelting layer still maintained an excellent conductive performance; Microhardness of the re- melting layer （ 425-540HV ） was obviously improved, the maximum reached 540HV, which was 2,25 times of the substrate （ about 240HV ） . The friction coefficient of the remelting layer （0.3） was much lower than the original CuCrS0 alloys （0.45）, the weight lost of remelting layer （0.15 mg） was much lower than the original CuCrS0 alloys （0.6 mg）, and the wear resistance of the alloy had an obvious improvement. Conclusion CuCr50 alloy could be refined, the microhardness and wear resistance could be improved by laser surface treatment under the condition of optimized process parameters.
出处
《表面技术》
EI
CAS
CSCD
北大核心
2016年第5期169-174,共6页
Surface Technology
基金
国家自然科学基金(51101177)
重庆市自然科学基金(cstc201250035)
重庆市科委攻关项目(cstc2014yykf B60004)
重庆市巴南区科技项目(2015TJ08)
重庆市模具技术重点实验室开放基金(2015TD19)~~
关键词
CuCr50合金
激光
组织
导电性
显微硬度
耐磨性
CuCr50 alloy
laser
microstructure
electrical conductivity
microhardness
wear resistance
作者简介
刘杰（1989-），男，硕士研究生，主要从事材料表面工程研究。
通讯作者：周志明（1976-），男，博士，教授，主要从事材料精密成形及材料表面工程方面的研究。
