Effect of hot isostatic pressing treatment on porosity reduction and mechanical properties enhancement of 316L stainless steel fabricated by binder jetting

In this work, a hot isostatic pressing (HIP) treatment was used to reduce the pores and improve the mechanical properties of binder jetting (BJ) fabricated 316L stainless steel. The relative density of the HIP treated samples sintered under vacuum, nitrogen, and argon atmospheres increased from 89.20 similar to 90.76% to 94.02 similar to 98.35%. The mean diameter of the internal closed pores decreased from 11.83 similar to 14.70 mu m to 0.94 similar to 1.53 mu m, and the internal porosity reduced from 5.47 similar to 8.67% to 0.14 similar to 0.35%. A remarkable enhancement of mechanical properties was achieved with the tensile strength by similar to 15% and the elongation by similar to 100% due to the reduction of porosity. The mechanical properties of the BJ 316L sintered under nitrogen and treated with HIP were even better than those of the direct powder HIP components due to the interstitial solution strengthening. These findings will be a valuable reference for optimising the HIP parameters to produce metal BJ components with superior mechanical properties.

Automated summary

In this study, the hot isostatic pressing (HIP) treatment effectively reduced the porosity and improved the mechanical properties of binder jetting (BJ) fabricated 316L stainless steel. The HIP treatment increased the relative density and decreased the mean diameter of internal closed pores and internal porosity. The mechanical properties, including tensile strength and elongation, were significantly enhanced due to the reduction of porosity. The mechanical properties of BJ 316L sintered under nitrogen and treated with HIP were even superior to those of the direct powder HIP components.