Microstructure and mechanical properties of laser powder bed fusion Ti-6Al-4V after HIP treatments with varied temperatures and cooling rates

This study examined non-standard Hot Isostatic Pressing (HIP) cycles for PBF-L Ti-6Al-4V, analyzing microstructure and tensile properties. Faster cooling rates (100 °C/min, 2000 °C/min) at 920 °C promoted a bi-lamellar α structure, with 2000 °C/min enhancing strength. Lower HIP temperatures (800 °C, 200 MPa) minimized coarsening, improving strength, while slow cooling (12 °C/min) led to the highest strength by limiting orthorhombic martensite formation. At 1050 °C, HIP reduced crystallographic texture and resulted in equiaxed prior-β grains, improving isotropy, but the 2000 °C/min cooling rate did not prevent grain boundary α formation, which lowered strength and elongation. Principal Component Analysis (PCA) was used to analyze the dataset.