Mechanical Properties and Residual Stress Analysis of ODS Ni Superalloy Fabricated by Laser Powder Bed Fusion Process

抄録

Oxide Dispersion Strengthened (ODS) superalloys are high-temperature alloys with enhanced mechanical properties at elevated temperatures. This is achieved by precipitating thermally stable fine oxides (such as Y₂O₃, ThO₂) or carbides within the metal matrix¹⁾. These alloys are primarily used in the field of superalloys and recently, the principle has been applied to various metals, including aluminum and copper alloys.

The ODS superalloys are generally manufactured by methods such as Hot Isostatic Pressing (HIP) and Spark Plasma Sintering (SPS) after mechanical alloy. These alloys have high strength, making it difficult to process complex shapes, and research on AM technology is being conducted as an alternative manufacturing method. In this study, the experiment was conducted with a Laser Powder bed fusion process using metal powder materials.

In this research, the ODS Ni-superalloy powder similar to the composition of MA6000 was manufactured using a gas atomization process. A specimen of the produced ODS Ni-superalloy powder was prepared by an L-PBF process. We measured changes in densification behavior of specimens according to L-PBF process parameters and conducted residual stress measurements in order to identify issues arising during the processing steps. Additionally, we analyzed the powder and PBFed specimens of ODS Ni-Super alloy using optical microscopy, scanning electron microscopy, XRD, and LPS analysis.