摘要
利用金相显微镜、扫描电镜和X射线衍射仪等测试手段,研究了经激光重熔前后的镍基合金热喷焊层的组织结构和抗高温氧化性能。试验结果表明,镍基合金热喷焊层组织比较粗大、不均匀,有疏松、气孔、夹杂等缺陷;经激光重熔处理后,其组织得到很大改善,主要由均匀、细小的树枝晶及枝晶间层片状共晶和化合物硬质相组成,气孔、夹杂等缺陷基本消除。镍基合金热喷焊层经激光重熔前后的氧化动力学曲线在600℃时均符合对数关系,而在800℃时则符合抛物线关系。经激光重熔处理的热喷焊层高温抗氧化性能得到了较大幅度的提高。
The microstructure and high temperature oxidation behavior of hot spray welded Ni-based alloy coating before and after being laser remelted were investigated by means of OM,SEM and XRD.The results show that hot spray welded Ni-based alloy coating offer coarser and inhomogeneous structure with looseness,bleb and inclusion;after being laser remelted,however,its microstructure was improved greatly,and consists mainly of homogeneous and fine dendrite and lameller eutectic structure and hard compounds between the dendrites,the bleb and inclusions have been eliminated from the coating.The oxidation kinetic curves of hot spray welded Ni-based alloy coating before and after laser remelting all follow logarithmic law at 600 ℃ and parabolic law at 800 ℃.The laser remelting can considerably improve on high temperature oxidation resistance of the hot spray welded Ni-based alloy coating.
出处
《热处理》
CAS
2012年第2期46-51,共6页
Heat Treatment
关键词
激光重熔
热喷焊层
组织
高温抗氧化性
laser remelting
hot spray welded coating
microstructure
high temperature oxidation resistance
