Jake Benzing1, Nik Hrabe1, Timothy Quinn1, Ryan White1, Ross Rentz1, Magnus Ahlfors2. 1. National Institute of Standards and Technology, Applied Chemicals and Materials Division, 325 Broadway, MS-647, Boulder, CO 80305, USA. 2. Quintus Technologies, 8270 Green Meadows Dr. N, Lewis Center, OH 43035, USA.
Abstract
Hot isostatic pressing (HIP) treatments are traditionally used to seal internal porosity, because defects exist in as-built Ti-6Al-4V parts produced by electron-beam melting powder-bed fusion. Standard HIP treatment of Ti-6Al-4V parts results in decreased strength due to coarsening of the microstructure. We present a new HIP strategy with the following steps: hold above the β-transus, rapid quenching, and tempering. This new HIP treatment seals internal porosity, causes a columnar-to-equiaxed transition in morphology of prior-β grains, changes the α lath aspect ratio, removes microstructural heterogeneities and matches the yield and ultimate tensile strength of the as-built condition.
Hot isostan class="Chemical">tic pressing (HIP) treatments are traditionally used to seal internal porosity, because defects exist in as-built Ti-6Al-4V parts produced by electron-beam melting powder-bed fusion. Standard HIP treatment of Ti-6Al-4V parts results in decreased strength due to coarsening of the microstructure. We present a new HIP strategy with the following steps: hold above the β-transus, rapid quenching, and tempering. This new HIP treatment seals internal porosity, causes a columnar-to-equiaxed transition in morphology of prior-β grains, changes the α lath aspect ratio, removes microstructural heterogeneities and matches the yield and ultimate tensile strength of the as-built condition.
Entities:
Keywords:
Additive manufacturing; Hot isostatic pressing; Microstructure; Recrystallization; Ti-6Al-4V
Authors: Miguel Lopez; Christina Pickett; Edel Arrieta; Lawrence E Murr; Ryan B Wicker; Magnus Ahlfors; Donald Godfrey; Francisco Medina Journal: Materials (Basel) Date: 2020-06-07 Impact factor: 3.623