METAL 2007 22. – 24. 5. 2007 Hradec nad Moravicí 1 MICROSTRUCTURE AND MECHANICAL PROPERTIES OF SPRAY DEPOSITED Ni-BASED SUPERALLOYS MI Guofa 1 , WANG Hongwei 2 , TIAN Shifan 3 , LI Zhou 3 (1. School of Materials Science and Engineering, Henan Polytechnic University, Jiaozuo, 454001, China; 2. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China; 3. Institute of Aeronautical Materials, Beijing 100095, China) Abstract: Three kinds of superalloys are prepared by spray deposited process. The analysis results of microstructures and mechanical properties indicate that the spray deposited preforms have higher integral densification and the oxygen content in each kind of superalloy is very lower. The microstructures are consisted of fine no dendritic equi-axed grain. The spray deposited superalloys has good ductility. The forging experiment illustrates that even though the once deformation of spray deposited GH742 alloy more than 60%, the crack can not be found. Also, the mechanical properties of spray deposited superalloys are increased significantly. Keywords: spray deposition, Ni-based superalloys, microstructure, mechanical properties 1 Introduction With the rapid development of space navigation, the demands of mechanical properties of high temperature structure materials for dynamical devices of aviation and spaceflight became more and more higher [1-4] . Conventional production process for high temperature structure materials applied as high temperature structure parts is casting-forging process. Even through vacuum arc melting or electroslag re-melting, the ingots still have coarsen grain, serious segregation and inhomogenous microstructure and mechanical properties that make the thermally process form become more difficult and the application of some alloys was restricted. The spray deposition process is an advanced process that forms the ingots nearing practical part shape by rapid solidification. Spray deposition can overcome the inherent defects of traditional forming process and the ingots formed by spray deposition have new microstructure and special mechanical properties [5-8] . In this paper three kinds of superalloy ingots were produced using spray deposition process and the microstructure and mechanical properties were analyzed and tested respectively. 2 Experimental procedures 2.1 Compositions and melting of master alloy Table 1 show the chemical compositions used as experimental alloys. The master alloys were prepared by using double vacuum induction melting.
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METAL 2007 22. – 24. 5. 2007 Hradec nad Moravicí
1
MICROSTRUCTURE AND MECHANICAL PROPERTIES OF SPRAY
DEPOSITED Ni-BASED SUPERALLOYS
MI Guofa1, WANG Hongwei
2, TIAN Shifan
3, LI Zhou
3
(1. School of Materials Science and Engineering, Henan Polytechnic University, Jiaozuo,
454001, China;
2. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin
150001, China;
3. Institute of Aeronautical Materials, Beijing 100095, China)
Abstract: Three kinds of superalloys are prepared by spray deposited process. The analysis
results of microstructures and mechanical properties indicate that the spray deposited
preforms have higher integral densification and the oxygen content in each kind of superalloy
is very lower. The microstructures are consisted of fine no dendritic equi-axed grain. The
spray deposited superalloys has good ductility. The forging experiment illustrates that even
though the once deformation of spray deposited GH742 alloy more than 60%, the crack can
not be found. Also, the mechanical properties of spray deposited superalloys are increased