Y改性Cr-Al渗层的组织及抗热冲击性能  

Microstructure and Thermal Shock Resistance of Y Modified Cr-Al Coating

作　　者：田兴达 梁国栋 王存喜 刘树静 李涌泉 TIAN Xingda;LIANG Guodong;WANG Cunxi;LIU Shujing;LI Yongquan(School of Material Science&Engineering,North Minzu University,Yinchuan 750021,China;College of Mechatronic Engineering,North Minzu University,Yinchuan 750021,China)

机构地区：[1]北方民族大学材料科学与工程学院,宁夏银川750021 [2]北方民族大学机电工程学院,宁夏银川750021

出　　处：《热加工工艺》2024年第10期64-67,共4页Hot Working Technology

基　　金：国家自然科学基金项目(51961003,52161009);宁夏自然科学基金项目(2020AAC02025);服务宁夏九大产业研究项目(FWNX42)。

摘　　要：采用粉末包埋渗法在DZ125镍基合金表面制备了Cr-Al-Y渗层。借助扫描电镜、能谱仪及X射线衍射仪,对Cr-Al-Y渗层组织结构及相组成进行了分析表征,对比研究了DZ125镍基合金基体及Cr-Al-Y渗层的抗热冲击性能。结果表明:经1050℃保温4 h所制备的Cr-Al-Y渗层均匀、致密、连续,厚度约为120μm,具有明显的沉积-扩散分布特征,渗层由外向内依次为Ni_(3)Cr_(2)、Ni_(3)Al浅表层,富含Ni_(3)Al的Ni_(3)Cr_(2)外层、Ni_(3)Cr_(2)中间层和Ni_(3)Cr_(2)、Ni_(3)Al内层。1000℃热冲击实验显示,DZ125基体热冲击31次后出现点状剥落,热冲击114次后目视可见裂纹,热冲击145次后表面出现块状剥落。Cr-Al-Y渗层热冲击142次后在渗层边缘出现细小裂纹,热冲击181次后出现可视细小裂纹,但渗层未出现剥落现象。这表明Cr-Al-Y渗层与基体合金之间不但具有良好的膜基结合力,还能在一定程度上提升DZ125基体合金的抗热冲击性能。Cr-Al-Y coating was prepared on the surface of DZ125 nickel base alloy by pack cementation process.The microstructure and phase composition were analyzed and characterized by scanning electron microscope,energy dispersive spectrometer and X-ray diffraction.The thermal shock resistance of DZ125 nickel base alloy and Cr-Al-Y coatings were compared.The results show that Cr-Al-Y coating prepared by holding at 1050℃for 4 h is 120μm thick and has a uniform,dense and continuous microstructure,and has a multi-layered structure with a superficial layer composed of Ni_(3)Cr_(2)and Ni_(3)Al,an outer layer composed of Ni_(3)Al-rich Ni_(3)Cr_(2),a middle layer composed of Ni_(3)Cr_(2)and an inner layer composed of Ni_(3)Cr_(2)and Ni_(3)Al.DZ125 matrix under the thermal shock tested at 1000℃shows that the spot spalling occurs after 31 times,visible cracks occur after 114 times,and massive spalling appears on the surface after 145 times.However,small cracks appear at the edge of the Cr-Al-Y coating after 142 times of thermal shock,and visible small cracks appear after 181 times of thermal shock,but the coating does not peel off,which indicate that the Cr-Al-Y coating has good film base bonding ability with DZ125 alloy,which can improve the thermal impact resistance of DZ125 alloy to a certain extent.

关 键 词：DZ125合金 Cr-Al-Y渗层 显微组织 热冲击 

分 类 号：TG174.44[金属学及工艺—金属表面处理]