Effect of microstructure on the electrochemical dissolution behaviour of Hastelloy® X superalloy processed by selective laser melting and heat treatments

Yingyue Yin; Jianhua Zhang; Shengzhao Yang; Tong Liu; Quanquan Han; Zhenhua Zhang; Huanqing Yang

Materials & Design (Aug 2021)

Effect of microstructure on the electrochemical dissolution behaviour of Hastelloy® X superalloy processed by selective laser melting and heat treatments

Yingyue Yin,
Jianhua Zhang,
Shengzhao Yang,
Tong Liu,
Quanquan Han,
Zhenhua Zhang,
Huanqing Yang

Affiliations

Yingyue Yin: Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education of China, School of Mechanical Engineering, Shandong University, Jinan 250061, China; National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China
Jianhua Zhang: Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education of China, School of Mechanical Engineering, Shandong University, Jinan 250061, China; National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China; Corresponding authors at: Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education of China, School of Mechanical Engineering, Shandong University, Jinan 250061, China.
Shengzhao Yang: Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education of China, School of Mechanical Engineering, Shandong University, Jinan 250061, China; National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China
Tong Liu: Anhui Key Laboratory of High-performance Non-ferrous Metal Materials, Additive Manufacturing Institute, Anhui Polytechnic University, Wuhu 241005, China
Quanquan Han: Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education of China, School of Mechanical Engineering, Shandong University, Jinan 250061, China; National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China; Corresponding authors at: Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education of China, School of Mechanical Engineering, Shandong University, Jinan 250061, China.
Zhenhua Zhang: Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Ministry of Education of China, School of Mechanical Engineering, Shandong University, Jinan 250061, China; National Demonstration Center for Experimental Mechanical Engineering Education, School of Mechanical Engineering, Shandong University, Jinan 250061, China
Huanqing Yang: Additive Manufacturing Technology Innovation Center for Aerospace Special Components of National Science and Technology Industry, Xian 710100, China

Journal volume & issue: Vol. 206
p. 109828

Abstract

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As a proven and highly efficient processing technique, electrochemical machining (ECM) is used for machining difficult-to-cut Ni-based superalloys (such as Hastelloy® X [HX] fabricated via selective laser melting [SLM]) with complex shapes. However, the metallic surface is susceptible to passive film formation to reduce the dissolution rate of HX under low current density conditions during the ECM process. This study focused on optimising microstructures for SLM-fabricated HX via heat treatment to enhance its electrochemical dissolution behaviour. The rates of electrochemical dissolution with different heat treatments increased in the following order: as-received < solution treatment (ST) < ageing treatment (AT) < solution and ageing treatment (ST + AT) in a 10 wt% NaNO3 solution at 35 °C. These results are attributed to 1) a large number of two representative precipitates (Fe2Mo and M23C6) in the grain or on the grain boundary (GB), 2) the decreased low-angle GB density (1.71%) and 3) few compact products on the surface of the samples with ST + AT. The parameter I, which is related to surface product composition, was quantitatively characterised based on the electrochemical dissolution rate of the samples. The enhanced mechanism of electrochemical dissolution is proposed to offer new insights into Ni-based superalloys in ECM applications.

Published in Materials & Design

ISSN: 0264-1275 (Print); 1873-4197 (Online)
Publisher: Elsevier
Country of publisher: United Kingdom
LCC subjects: Technology: Electrical engineering. Electronics. Nuclear engineering: Materials of engineering and construction. Mechanics of materials
Website: https://www.journals.elsevier.com/materials-and-design

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