Laser metal deposition shaping (LMDS) is a state-of-the-art technology that combines rapid prototypingand laser processing. There are many factors affecting the quality, precision, microstructure and per-formance of the LMDS-deposited parts. Among these factors, substrate preheating is a significant onebecause it can change the heat history of the LMDS process. Preheating is generally adopted to reduce theresidual stresses and the risk of thermal distortion and cracking. However, it changes the heat transferconditions and affects the final microstructure and properties. In this work a numerical simulation modelwas established to analyze the heat transfer characteristics between deposited material and substrate,the influence rules of substrate preheating on the thermal behavior during LMDS, and the distributioncharacters of temperature and stress field. And then, the experimental methods were used to evaluatethe effects of substrate preheating on the surface quality, microstructure, composition, hardness distri-bution, and mechanical properties of as-built thin-wall parts. The experimental results primarily agreewith the theoretical analysis and numerical model, which indicates that in terms of the varied thermo-mechanical coupled field, the investigated microstructure and properties of formed components dependconsiderably on the initial temperature of the substrate, so the LMDS process can be effectively adjustedand controlled by means of substrate preheating. 2014 Elsevier B.V. All rights reserved