Portevin-Le Châtelier Effect in a Powder Metallurgy Co-Ni-Based Superalloy

Chao Li; Jianwei Teng; Biaobiao Yang; Xianjue Ye; Lan Huang; Yong Liu; Yunping Li

doi:10.3390/ma15082796

Portevin-Le Châtelier Effect in a Powder Metallurgy Co-Ni-Based Superalloy

Materials (Basel). 2022 Apr 11;15(8):2796. doi: 10.3390/ma15082796.

Authors

Chao Li¹, Jianwei Teng¹, Biaobiao Yang^{1

2

3}, Xianjue Ye¹, Lan Huang¹, Yong Liu¹, Yunping Li¹

Affiliations

¹ State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China.
² IMDEA Materials Institute, C/Eric Kandel 2, Getafe, 28906 Madrid, Spain.
³ Department of Materials Science, Polytechnic University of Madrid/Universidad Politécnica de Madrid, E.T.S. de Ingenieros de Caminos, 28040 Madrid, Spain.

Abstract

The Portevin-Le Châtelier (PLC) effect in a powder metallurgy (PM) Co-Ni-based superalloy was systematically investigated via the tensile tests at temperatures ranging from 200 to 600 °C and strain rates at 1.0 × 10^-4 to 1.0 × 10^-2. Both normal and inverse PLC effects were observed in the PLC regime, and the former appeared in the A and B types at a low temperature, whilst the latter appeared in the C type at an elevated temperature. Both positive and negative strain rate sensitivities (SRS) were shown in PLC regime, and SRS should be derived from same types of serrations. Based on the calculated activation energy, the substitutional atom Mo is considered to take primary responsibility for the PLC effect in present alloy.

Keywords: Co-Ni-based superalloy; Portevin-Le Châtelier (PLC) effect; dynamic strain aging; strain rate sensitivity.