铬(Cr)添加量对真空粉末熔覆镍铬-碳化铬(NiCr-Cr_3C_2)复合涂层微观组织的影响  

Influence of Cr-Addition on Microstructures of Vacuum PowderBrazed NiCr-Cr_3C_2 Composite Coatings

作　　者：王德[1] 谢玉江[1,2] 王明生[2] 张友亮[1] 郭炜[1] 付远[1] 

机构地区：[1]江西省科学院应用物理研究所,南昌330029 [2]中国科学院金属研究所,沈阳110016

出　　处：《真空科学与技术学报》2016年第8期866-872,共7页Chinese Journal of Vacuum Science and Technology

基　　金：江西省科学院省院协同创新项目(2014-YYB-16);江西省科学院科研专项资金(2014-XTPH1-16)

摘　　要：采用高温真空粉末熔覆工艺在镍基高温合金表面制备了Cr改善的Ni Cr-Cr_3C_2复合涂层,涂层与基体形成冶金结合。通过添加不同含量(0%,10%,20%,30%(质量分数))的Cr粉末,研究了Cr含量对涂层微观组织,相组成及界面扩散的影响。结果表明,Cr的添加促进了涂层中硅(Si)元素的消耗并形成Cr3Si,同时抑制了界面处脆性相Ni3Si的产生。随着Cr添加量的增多,二次反应区厚度及界面处的Ni3Si含量均相应减少。The Ni Cr-Cr_3C_2 composite coatings,synthesized by high temperature vacuum powder brazing on substrate of Ni-based super-alloy（ K438） with brazing-flux of Ni Cr19Si10（ BNi-5）,were modified by adding Crpowder. The influence of the added Cr-content on the microstructures,phase-structures and mechanical properties of the coatings were investigated with X-ray diffraction,scanning electron microscopy,energy dispersive spectroscopy,and transmission electron microscopy. The results show that the addition of Cr-powder significantly improved the microstructures,phase-structures and interfacial adhesion of the coatings. To be specific,as the added Cr-content increased from 0. 0wt. % to 30. 0wt. %,the secondary reaction zone（ SRZ） thickness decreased; the thickness of the interfacial diffusion zone（ IDZ） increased but abruptly decreased at 30 wt. % Cr; the content of Cr_3 Si increased,accompanied by a considerable reduction of the brittle-phase Ni3 Si at the interface,possibly because the added Cr consumed most Si of the flux in formation of Cr_3 Si.

关 键 词：真空粉末熔覆 复合涂层 高温合金 微观组织 

分 类 号：TF124[冶金工程—粉末冶金] TG454[冶金工程—冶金物理化学]