On the Benefits of High Pressure Heat Treatment Additively Manufactured CoCr

Laser Powder Bed Fusion (LPBF) processes are becoming more viable in place of traditional castings. To compete, novel material grades are being considered with additive manufacturing (AM). In maximizing performance through AM, novel approach to heat treatment and Hot Isostatic Pressing (HIP) processing needs to be considered. It has been accepted that combining key heat treatment processes with (HIP) by utilizing fast cooling rates can benefit static properties as well as improve turn-around time for HIP processing. Argon pressures up to 207 MPa with cooling rates above 170 C° per minute are now available in production sized HIP systems to design ideal HIP cycles for high pressure heat treatment. Additive manufacturing with high pressure heat treatment is in need of further investigation for establishing new qualification standards.

This study investigates designed High-Pressure Heat Treatment cycles to consider mechanical performance on LPBF CoCr. The combined cycles investigate possible alternatives to historically accepted two step HIP then heat treat processing by combining densification with solution treatment into one step. Tensile, fatigue, and toughness performance are explored to seek optimal properties and with reduced variability.