Direct metal laser sintering of very fine metal powders

Abstract

Direct Metal Laser Sintering (DMLS) is a net shape fabrication technology that has been developed especially to fulfill the requirements of rapid tooling. The most important factors for successful rapid tooling are: 1) accuracy, 2) surface quality, 3) material properties and 4) speed. Surface quality has been the major concern for development work because rapid tooling applications require very smooth surfaces and finishing work is often needed. The quality of all surfaces can be greatly improved by reducing layer thickness and adjusting optimal scanning parameters in the DMLS process. Simultaneously stair-stepping effect can be minimized and almost faded out. Straightforward progress to smaller layer thickness has required material development work of finer metal powders and intensive research work for optimal laser processing. Simultaneously part building strategies have become more intelligent. It has been proved in practical cases that even 20 µm thin layers can be used for building steel parts with superior surface quality.This paper describes some of the key features for Direct Metal Laser Sintering of very fine metal powders. Latest results and experiences of research and development team at Rapid Product Innovations (formerly Electrolux Rapid Development) are discussed.Direct Metal Laser Sintering (DMLS) is a net shape fabrication technology that has been developed especially to fulfill the requirements of rapid tooling. The most important factors for successful rapid tooling are: 1) accuracy, 2) surface quality, 3) material properties and 4) speed. Surface quality has been the major concern for development work because rapid tooling applications require very smooth surfaces and finishing work is often needed. The quality of all surfaces can be greatly improved by reducing layer thickness and adjusting optimal scanning parameters in the DMLS process. Simultaneously stair-stepping effect can be minimized and almost faded out. Straightforward progress to smaller layer thickness has required material development work of finer metal powders and intensive research work for optimal laser processing. Simultaneously part building strategies have become more intelligent. It has been proved in practical cases that even 20 µm thin layers can be used for building steel parts with s...