Effect of oxygen content and heat treatment on carbide precipitation behavior in PM Ni-base superalloys  

作　　者：Heng-san Liu Lin Zhang Xin-bo He Xuan-hui Qu Hong-min Zhu Guo-qing Zhang 

机构地区：[1]State Key Laboratory for Advanced Metals and Materials, Beijing Key Laboratory for Powder Metallurgy and Particulate Materials, University of Science and Tech-nology Beijing, Beijing 100083, China [2]School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China [3]National Key Lab of High Temperature Structural Materials, Beijing Institute of Aeronautical Materials, Beijing 100095, China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2012年第9期827-835,共9页矿物冶金与材料学报（英文版）

基　　金：supported by the Science and Technology Planning Foundation of Beijing (No.D09080300510901);the National Natural Science Foundation of China (No.51104007)

摘　　要：The influence of oxygen content and heat treatment on the evolution of carbides in a powder metallurgy （PM） Ni-base superalloy was characterized. The results reveal that oxygen content has little influence on the precipitation of carbides inside the particles. However, under the consolidated state, stable Ti oxides on the particle surface act as nuclei for the precipitation of prior particle boundaries （PPB）. Also, oxygen can diffuse internally along grain boundaries under compressive stress, which favors the precipitation of carbides inside the particles. Therefore, a higher amount of carbides will appear with more oxygen content in the case of consolidated alloys. It is also observed that PPB can be disrupted into discontinuous particles at 1200℃, but this carbide network is hard to be eliminated completely. The combined MC-M23C6 morphology approves the nucleation and growth mechanism of carbide evolution.The influence of oxygen content and heat treatment on the evolution of carbides in a powder metallurgy （PM） Ni-base superalloy was characterized. The results reveal that oxygen content has little influence on the precipitation of carbides inside the particles. However, under the consolidated state, stable Ti oxides on the particle surface act as nuclei for the precipitation of prior particle boundaries （PPB）. Also, oxygen can diffuse internally along grain boundaries under compressive stress, which favors the precipitation of carbides inside the particles. Therefore, a higher amount of carbides will appear with more oxygen content in the case of consolidated alloys. It is also observed that PPB can be disrupted into discontinuous particles at 1200℃, but this carbide network is hard to be eliminated completely. The combined MC-M23C6 morphology approves the nucleation and growth mechanism of carbide evolution.

关 键 词：powder metallurgy nickel alloys SUPERALLOYS OXYGEN heat treatment carbides PRECIPITATION 

分 类 号：TG146.15[一般工业技术—材料科学与工程] TG142.31[金属学及工艺—金属材料]