| Abstract Scope |
As additive manufacturing (AM) continues to find applications in aerospace, power generation, oil/gas, and medical markets, there is a desire to identify AM parameter sets for crack-prone alloys. These materials are difficult to weld because they are susceptible to hot cracking, strain-age cracking and thermal stresses. In laser powder bed fusion (LPBF) processes, conventional energy density equations consider process parameters but ignore machine and material properties. Carpenter Technology has developed a new approach that integrates process, machine and materials parameters, and leads to the suppression of porosity and cracking. Usage of this approach aides in the development of parameter sets for existing alloys and accelerates the design of new alloys specifically tailored to LPBF AM. Examples of crack-free AM Hastelloy® and Custom 465® are reviewed. Microstructures in as-built and as-aged conditions along with performance of a high-γ’ Ni-base and a Co-Ni superalloy specifically optimized for AM are also discussed. |