摘要
为了提高铝合金材料的表面性能,使其具有较高的硬度和耐磨性,利用激光熔覆技术在6063铝合金表面制备了添加稀土氧化物CeO2的Ni60合金熔覆层。分析了激光熔覆CeO2+Ni60熔覆层的宏观形貌、显微组织及硬度,研究了其摩擦磨损性能,并与未添加稀土的Ni60合金熔覆层和铝合金基体进行了对比研究。结果表明,加入2%CeO2可降低Ni60熔覆层表面起伏,获得较好的熔覆层宏观形貌,同时有效地减少Ni60熔覆层中的裂纹、孔洞和夹杂物,促进晶粒细化,提高熔覆层的组织均匀性;添加2%CeO2的Ni60熔覆层比未加稀土的Ni60熔覆层组织更加均匀,晶粒较细小,气孔等组织缺陷更少,熔覆质量较好;在相同深度位置的显微硬度,2%CeO2+Ni60熔覆层明显高于Ni60熔覆层,2%CeO2+Ni60熔覆层最高硬度可达HV0.051180,是6063铝合金基体平均硬度的8.4倍;在相同磨粒磨损条件下,2%CeO2+Ni60熔覆层试样的耐磨性是铝合金基体的7.1倍,是Ni60熔覆层试样的1.6倍;激光熔覆Ni60可以显著降低铝合金表面摩擦系数,而添加稀土元素Ce能提高Ni60熔覆层的摩擦系数稳定性,从而改善耐磨性能。
To improve the surface properties of aluminum alloys,such as higher hardness and wear resistance,a rare earth CeO2＋Ni60 alloy cladding layer bonded to substrate was prepared on the surface of aluminum alloy by laser cladding. The macroscopic morphology,microstructure,and microhardness of laser cladding rare earth 2% CeO2＋ Ni60 alloy coatings on Al alloys were investigated,and its friction and wear behavior were also studied. A comparative study on Ni60 alloy cladding layer and aluminum alloy was made as well. The results showed that the Ni60 cladding layer added 2% CeO2 could reduce surface relief,and get a better macro-morphology cladding layer; the cracks,holes and entrapment in the coatings reduced; the grains became small,the microstructure uniformity was improved,and the hardness and wear resistance of the coatings increased. The microhardness of 2% CeO2＋ Ni60 cladding layer wassignificantly higher than that of Ni60 cladding layer in the same depth of position,and the highest microhardness of 2% CeO2＋ Ni60 cladding layer was up to HV0. 051180,which was 8. 4 times the average microhardness of 6063 Al matrix. Under the same abrasive wear conditions,the wear resistance of 2% CeO2＋ Ni60 cladding layer was 7. 1 times that of untreated aluminum alloy,and 1. 6 times that of Ni60 cladding layer; Ni60 cladding layer could significantly reduce the friction coefficient of aluminum alloy,and the rare-earth CeO2＋ Ni60 cladding layer could improve the stability of friction coefficient and thus improve wear resistance.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2014年第5期800-806,共7页
Chinese Journal of Rare Metals
基金
国家自然科学基金青年基金项目(51201043)
国家自然科学基金项目(51264007)
广西自然科学基金重点项目(2010GXNSFD013008)
广西科学研究与技术开发科技攻关计划项目(桂科攻12118020-2-2-1)
广西信息材料重点实验室项目(桂科能1210908-07-Z)资助
关键词
激光熔覆
稀土
铝合金
摩擦磨损
laser cladding
rare earth
aluminum alloy
friction and wear behaviors
