Laser micro sintering - a quality leap through improvement of powder packing

Abstract

Laser micro sintering, a modification of selective laser sintering for freeform fabrication of micro-parts, was continuously upgraded since its first application. Poor density of the powder layers has been a persisting problem that had to be dealt with from the beginning. One solution was the application of high intensity q-switched laser pulses. Compaction of the material and improvement of the sinter resolution was achieved. But with these pulse-regimes only limited density of the sintered body has been achievable. Recently special efforts have been made to get rid of or at least reduce these drawbacks by markedly higher compaction of the respective powder layers. There is clear evidence that with sufficiently compacted powder layers even laser micro sintering with continuous radiation should be feasible. Till recently laser sintering of metal had been applied mainly to produce monolithic components. With the upgraded technique direct generation of micro devices with freely movable subassemblies can be possible.