Research progress in laser solid forming of high-performance metallic components at the state key laboratory of solidification processing of China

Direct fabrication of metallic components using laser solid forming (LSF) has been shown to be a viable and promising manufacturing technology. In the present article, the mechanical properties and microstructure characteristics of LSF metallic parts are reviewed, and the main progress on the research and application of LSF in the State Key Laboratory of Solidification Processing of Northwestern Polytechnical University of China are reviewed. It is found that the LSF metallic parts, especially LSF titanium alloy parts, present outstanding mechanical properties usually in the class of those of wrought parts. LSF parts generally exhibit typical columnar dendrites/grains epitaxially growing through several deposition layers with the growth direction along laser deposition direction, which leads to a larger grain size in LSF parts. However, the microstructure features inside the grain are usually finer compared with a forging part due to the rapid solidification and cooling during LSF, and even composition distribution without macrosegregation is obtained. These microstructural characteristics are responsible for the excellent mechanical properties. In recent years, direct fabrication, hybrid manufacturing, and high-performance repairing, which are based on the LSF route, have been applied widely in aviation, aerospace, and the medical field.