摘要
采用 SEM、TEM和 EDAX等方法研究了熔覆工艺对 Ni6 0 A激光熔覆层微观组织的影响。熔覆层由胞枝状 γ- Ni基固溶体、树枝状 M7C3 、颗粒状 Cr B、Ni+ M2 3 C6及 Ni+ Ni3 B共晶组织组成 ,结合区由具有定向快速凝固组织特征的胞状共晶组织组成 ,结合区底部的熔合带是由 γ- (Fe,Ni)固溶体形成的平面晶。相同工艺参数的搭接熔覆使涂层的稀释度增大 ,在保证涂层与基体形成良好冶金结合的前提下 ,适当增大扫描速度或降低功率密度有利于涂层组织的细化 。
By means of SEM,TEM and EDAX,the effect of cladding technology on the microstructure of the laser clad Ni60A coating is studied.The coating consists of cellular-dendritic γ-Ni based solid solution,dendritic M 7C 3,granular particle CrB,Ni+M 23 C 6 and Ni+Ni 3B eutectic structures.Bonding zone is composed of cellular eutectic structures with directional fast solidified structure features. Bonding belt of the botton of the bonding zone is composed of plane crystal formed by γ-(Fe,Ni) solid solution.The lapped cladding of the same parameters makes the dilution of the coating increase.In the guarantee of the forming of the metallurgical combination between coating and substrate,increasing scanning speed or decreasing power density properly will profit the refinement of the coating structure and decrease the dilution of the coating by substrate.
出处
《应用激光》
CSCD
北大核心
2001年第6期381-384,共4页
Applied Laser
