Microstructure and mechanical properties of K438 alloy processed by selective laser melting and subsequent heat treatment
Artikel i vetenskaplig tidskrift, 2022

In this work, K438 nickel-based high-temperature alloy was successfully prepared and heat-treated by selected laser melting (SLM). A comparative study of the microstructure and mechanical properties of different samples was carried out to reveal the influence of SLM process parameters and heat treatment. The layer-by-layer fabrication in SLM created a special sunflower-shaped dendrites and the extremely fast cooling rate resulted in a large number of low angle grain boundaries (LAGBs) and inhomogeneous γ’ phases being found in the samples. After heat treatment, the orbital structure within the tissue disappeared and the coarse square γ’ phase (0.4 to 0.8 μm) melted and precipitated fine rounded secondary γ’ phases (0.05 μm). During recrystallisation, the LAGBs to high angle grain boundaries (HAGBs) transition occurs and many fine grain clusters appear at the grain boundaries, resulting in subcrystalline nucleation based on subcrystals and an increase in UTS.

Mechanical properties

Selective laser melting (SLM)

Heat treatment

Additive manufacturing

K438 nickel-based superalloy

Författare

Hua Yan

Shanghai University of Engineering Science

Hohai University

Jiangsu Shenyuan Group

Guangyu Zhu

Shanghai University of Engineering Science

Haichuan Shi

Shanghai University of Engineering Science

Peilei Zhang

Shanghai University of Engineering Science

Haichao Li

Shanghai University of Engineering Science

Qinghua Lu

Shanghai University of Engineering Science

Zhiyuan Li

Chalmers, Mekanik och maritima vetenskaper, Marin teknik

Materials Characterization

1044-5803 (ISSN)

Vol. 191 112116

Ämneskategorier

Keramteknik

Livsmedelsteknik

Metallurgi och metalliska material

Styrkeområden

Materialvetenskap

DOI

10.1016/j.matchar.2022.112116

Mer information

Senast uppdaterat

2022-07-26