Dmls – Development History and State of the Art

This paper summarizes the state of the art of direct metal laser-sintering (DMLS) in 2004, put into perspective by a review of its history from its roots in the 1970s, and discusses the trends going into the future. Since the 1970s, DMLS has evolved from an idea to a powerful commercial technology. The "family tree" of DMLS is explained with reference to related methods such as laser-cladding, indirect metal laser-sintering and plastic laser-sintering. Key aspects of the various machine concepts are reviewed, for example regarding laser sources (CO2, YAG, fibre lasers etc.) and powder layer generation methods (fluidized beds, blades, brushes, milling-based systems etc.), and also materials developments and process strategies. Some examples are given of performance improvements over the years. Finally, the application trends are briefly reviewed including rapid tooling, series production tooling, rapid metal prototyping and production of end-use parts.