Effect of Hot Isostatic Pressing Process Parameters on Properties and Fracture Behavior of Tungsten Alloy Powders and Sintered Bars

Abstract

In order to investigate the effect of hot isostatic pressing (HIP) process parameters on the properties and fracture behavior of tungsten alloy, HIP experiments with different process parameters were carried out, and the relative density, Rockwell hardness, tensile properties, and tensile fracture behavior were analyzed. The results show that after HIP, the tungsten alloy samples obtained further densification, higher relative density and hardness, and lower dispersity. At 1300 °C and 140 MPa, the sintered bar achieved excellent mechanical properties: yield strength increased by 16.5%, tensile strength increased by 16.1%, and fracture strength increased by 85.3%. Comparing the two processes, the mechanical properties of tungsten alloy powders formed directly via HIP were not as good as those of the sintered bars. In addition, after HIP, the fracture mode of the tungsten alloy sintered bar samples was mainly ductile tear, and that of the tungsten alloy powder samples was mainly a full brittle fracture.

Research Status of Manufacturing Technology of Tungsten Alloy Wire

“…Materials Relative Densities Molding [27] W 94.8% Hot isostatic pressing [32] 90W-Ni-Fe-Cu Above 98.5% Hot isostatic pressing [33] W/CuY 98.1% W/CuCrZr 98.8% Hot isostatic pressing [34] W 97.2% Spark plasma sintering [34] W 91.7% Hot isostatic pressing) [35] 93W-Ni-Fe 98.8% Table 3 shows the relative densities of the samples obtained by different manufacturing methods. In summary, hot isostatic pressing technology can significantly improve the densification of tungsten alloys and improve their properties, but how to accurately determine the process parameters such as temperature and pressure is a key issue in the process of hot isostatic pressing.…”

“…Molding [27] W 94.8% Hot isostatic pressing [32] 90W-Ni-Fe-Cu Above 98.5% Hot isostatic pressing [33] W/CuY 98.1% W/CuCrZr 98.8% Hot isostatic pressing [34] W 97.2% Spark plasma sintering [34] W 91.7% Hot isostatic pressing) [35] 93W-Ni-Fe 98.8%…”

“…After hot isostatic pressing at 1650 °C for 2 h, the relative density reached a maximum of 97.2%, while the maximum bending strength increased to 761 MPa. Hu Biao and Cai Gaoshen [35] used the hot isostatic pressing process for 93 W-Ni-Fe sintered rods and powders, respectively, and obtained a relative density of 98.8% for the sintered rods and 92.7% for the powders when the temperature was increased by 100 °C, with relative densities increasing by 0.86% and 2.3%, respectively. It was also found that increasing both temperature and pressure increased the relative density of the tungsten alloy, with tem- Wang Jianning et al [32] prepared four kinds of 90W-Ni-Fe-Cu alloys with different Cu additions by hot isostatic pressing.…”

Compactability Regularities Observed during Cold Uniaxial Pressing of Layered Powder Green Samples Based on Ti-Al-Nb-Mo-B and Ti-B

“…Powder metallurgy methods serve as the primary technologies for manufacturing composite materials. These methods encompass various techniques, including selective laser sintering [31][32][33][34][35], hot isostatic pressing [36][37][38], spark plasma sintering [39][40][41][42], selfpropagating high-temperature synthesis (SHS) [43][44][45][46], and several other methods [47][48][49][50], wherein pressed powder green samples serve as precursors. The quality of the green sample, which encompasses factors like uniform density along its height and radius, relative density across the entire batch, and technological strength, significantly influences the physical, mechanical, and operational properties of the resulting products.…”