Product Code: JLA_1_2_27

Authors:
J. Mazumder
S. Sircar
C. Ribaudo
A. Kar
Laser‐Aided Materials Processing Laboratory, Department of Mechanical and Industrial Engineering, University of Illinois at Urbana‐Champaign, 1206 West Green Street, Urbana, Illinois 61801, U.S.A.

Synthesis of nonequilibrium phases provides an opportunity to engineer new materials with novel properties. The technique of laser surface modification (LSM) provides a unique means of synthesizing novel non‐equilibrium materials by taking advantage of the inherent rapid heating and cooling rate of the process. LSM can be used to obtain specific surface properties significantly different from bulk properties. Also, by depositing multiple layers by LSM, nonequilibrium materials with specific properties can also be synthesized in near net shape. This approach is now pursued for various applications, including aerospace engine and structural components for high temperature service and wear and corrosion resistant components for chemical and engineering industries. This paper describes a synthesis of Ni‐Al‐Cr‐Hf alloys with extended solid solution of Hf by laser cladding techniques. A 10 kW CW CO₂ laser with mixed powder feed was used for the cladding process. Microstructural studies reveal the formation of dendrites with about 11–14 wt % Hf along with eutectic structure in the interdendritic zones. Isothermal oxidation tests revealed improved oxidation resistance at 1200°C compared to conventional nickel superalloys. A mathematical model is also reported for the prediction of the effect of laser process parameters on non‐equilibrium phase diagram.