Hot isostatic pressing (HIP) is often used as a post process for powder bed fusion (PBF) Ti-6Al-4V to eliminate internal defects such as lack-of-fusion and gas porosity and achieve 100% density and improved material properties. Even though HIPing is used, the PBF printing process is typically optimized for achieving maximum density in the as-printed condition. This presentation will go through a new approach where the PBF printing process can be performed significantly faster if a higher amount of porosity in the as-printed condition is allowed. The higher amount of porosity in the as-printed condition is eliminated by the HIP process to 100% density. The printing process speed is increased by increasing the scan speed of the beam and/or increasing the hatch spacing. A study has been made showing that it is possible to print faster with more porosity, HIP the material to 100% and get as good material properties for L-PBF Ti-6AL-4V. Density measurements, micrographs, mechanical testing results and calculations and measurement of time savings in the pointing process will be presented. Up to 50% of laser time in the printing process can be reduced by this approach but there is a limit of how much porosity that can be allowed in the as-printed condition to still get good material properties after HIP.
- Have a better understanding on how HIP can eliminate internal defects in PBF material
- Have a better understanding on how faster printing parameters is related to more porosity in the material in the as-built condition
- Increase the build rate of their PBF process with maintained material quality and performance with some process optimization