Mechanical and thermal expansion behavior of laser deposited metal matrix composites of Invar and TiC

For laser assisted shape deposition manufacturing, residual stresses caused by the temperature gradient and material property mismatches result in part inaccuracy, warpage, or even delamination. The use of low coefficient of thermal expansion (CTE) materials such as Invar promises to reduce deformations caused by internal stresses. Thus, to obtain high quality of prototypes for molding and tooling, there is a need for a material with a low coefficient of thermal expansion, high yield strength, good toughness, and high wear resistance. This investigation concentrates on the development of laser-deposited composites of Invar and TiC. The experimental results show that the new materials yield exceptionally Low CTE, high hardness and yield strength, and reasonable ductility. The class of materials studied in this work promises to reduce deformation caused by residual stresses and improves mechanical properties significantly. (C) 2000 Elsevier Science S.A. All rights reserved.