摘要
为解决激光熔覆工艺制备Ni/Ni3Al基双性能材料过程中产生的裂纹问题并使之保持良好的力学性能,采用优化工艺参数获得了冶金质量良好的双性能样品。研究发现,对制备过程中裂纹产生的原因与机理进行分析,通过改变激光参数能够有效降低涂层的开裂倾向。采用扫描电子显微镜(SEM)和X射线衍射(XRD)等检测手段对单层和多层涂层进行微观组织形貌、成分分析,物相表征,结果发现单层熔覆样品由于Ni基合金的稀释作用在涂层中形成了少量Al8Cr5和Al4Cr Ni15相,而进行多层熔覆后,涂层样品物相为单一的Ni3Al相,单一的物相组成可保持Ni3Al基材料优异的性能,更能充分体现双性能材料的特点。对激光熔覆制备双性能原始样品和经过870℃时效处理之后的试样分别进行硬度测试,结果表明,制备得到的双性能样品在较高温度下依然能够保持较高的硬度值。
Ni/Ni3 Al double performance coatings with good metallurgical quality are obtained through optimizing the process parameters and using multi-laser cladding. Double performance materials crack-sensitivity can be reduced effectively by changing the laser processing parameters. The generation and mechanism of cracks in the laser processing are investigated. The microstructure, composition and phase constitution of the coatings are characterized using scaming electron microscope（SEM）, X-ray diffrcaction（XRD）, respectively. The results reveal that small amount phases of Al8Cr5 and Al4Cr Ni15 are precipitated in the single clad coating due to the dilution of Nibased alloy. Additionally, a single Ni3 Al phase is produced in the coating by means of multilayer cladding, which can keep good properties of Ni3Al-based materials and perform the characteristics of double-properties materials more sufficiently. The micro-hardness testing of the coatings show that the double-properties material is able to maintain high hardness even under higher temperature.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2015年第3期191-197,共7页
Chinese Journal of Lasers
基金
国家973计划(2011CB606365-3)
国家自然科学基金(50971004)
研究生创新平台建设(101000543214524)
关键词
激光熔覆
双性能材料
裂纹敏感性
显微硬度
时效处理
double performance materials
laser cladding
crack-sensitivity
micro-hardness
aging treatment
