Effect of the Prior Particle Boundary on the Microstructure and Mechanical Properties of Hot-Isostatic-Pressed IN718 Alloy

Abstract

The effects of particle surface contamination and of the prior particle boundary on the microstructure and mechanical properties of hot-isostatic-pressed IN718 alloy were investigated in this study. A thermal-plasma-droplet-re ning technique was conducted to reduce the surface contamination; i.e., oxygen and carbon contents in the gas-atomized IN718 powder. The tensile ductility of hot-isostatic-pressed materials was comparable to those of conventionally wrought materials at room temperature and at 650 C. At 650 C, the hot-isostatic-pressed and heat-treated specimens exhibited worse ductility than the conventionally wrought specimen because of the increased number of brittle precipitates, such as oxides, oxy-carbides and δ phases in the heat-treated specimens. The process of crack nucleation and propagation along the prior particle boundary will take place more easily at high temperatures.

Effect of HIP post-treatment on the HIPed Ti6Al4V powder compacts

“…As a consequence, the number of high-angle grains decreases after HIPPT, while the variation in the numbers of low-angle grains can be ignored. Equiaxed grains can be found both before and after HIPPT, which is consistent with the microstructure above and the reference [19]. The grains in both types of powder compacts are randomly orientated (see Figure 7(c,d)).…”

Effect of the particle size distribution on physical properties, composition, and quality of gas atomized Astroloy powders for HIP application

“…Furthermore, the Al atomic radius is slightly shorter than Titanium one; thus, its diffusivity will be facilitated. Similar theories were also proposed by Kuo and Kakehi [21], who worked with a different nickel-based superalloy containing Cr Ti and Al as in the current work.…”