Oxide reinforced Ni base composite prepared by spark plasma sintering

Guoliang Zhu,Sheng Jiang,Anping Dong,Wei Wang,Wenheng Wu,Yilong Pu,Shiqi Zhao,Liang Zhang,Rui Wang,Katsuyuki Kida

doi:10.1051/matecconf/201713003008

Abstract

Y 2 O 3 is a favourable reinforcement for the oxide dispersion strengthened superalloy due to its good high temperature stability, excellent strength and large elastic modulus. In this work, Y 2 O 3 is introduced into the K4169 superalloy aiming to improve its high temperature properties. The high quality Y 2 O 3 and K4169 powder mixture can be obtained with the addition of the process control agent of stearic acid after high energy ball milling, and the Y 2 O 3 /K4I69 composite with uniformly dispersed reinforcement of nanoscale Y 2 O 3 particles are finally synthesized with the ball-milled powders by using spark plasma sintering.

Highlights

Different from the technical route of the optimization of composition and microstructure, the oxide dispersion strengthening (ODS) is an effective method to improve the high temperature performances of materials [1]
The Y3Al5O12, YAlO3 and Y4Al2O9 phases are formed in the MA6000 alloy due to the reactions between Y2O3 and Al during the mechanical alloying [4]. the addition of Hf in PM1000 ODS superalloy leads to the formation of Y2Hf2O7 which has better interface characteristics with the matrix compared to Y2O3 [5]
No obviously scattered Y2O3 particles are found in the ball-milled powders, indicating that the nanoscale Y2O3 powder and microscale K4169 powders are homogeneously mixed after high energy ball milling (HEBM)

Summary

Introduction

Different from the technical route of the optimization of composition and microstructure, the oxide dispersion strengthening (ODS) is an effective method to improve the high temperature performances of materials [1]. The synthesis of ODS superalloys has attracted wide attention. Yttria (Y2O3) is a common reinforcement for ODS superalloy due to its high thermal stability, favourable strength and elastic moudulus [2]. Benjamin [3] has prepared the Y2O3 reinforced superalloy by using mechanical alloying in 1970s. A few ODS superalloys have been invented, including MA754 and PM3000, in which the concentration of Y2O3 is 0.6wt.% and 0.9wt.% Y2O3 respectively. The superalloys strengthened by Y2O3 have been widely applied in aero engines. Y2O3 can react with the elements in matrix or other added elements to form new reinforcing phases, resulting in better strengthening effect. The addition of Hf in PM1000 ODS superalloy leads to the formation of Y2Hf2O7 which has better interface characteristics with the matrix compared to Y2O3 [5] The Y3Al5O12, YAlO3 and Y4Al2O9 phases are formed in the MA6000 alloy due to the reactions between Y2O3 and Al during the mechanical alloying [4]. the addition of Hf in PM1000 ODS superalloy leads to the formation of Y2Hf2O7 which has better interface characteristics with the matrix compared to Y2O3 [5]

Methods

Results

Conclusion