Abstract
At present. the research on rapid tooling by the selective laser sintering (SLS) method is mainly focused on the production of parts with high accuracy and definition. Very little effort has been devoted to the microstructural evolution and mechanical properties of this material. This paper gives detailed information about microstructural development and mechanical behaviour of Rapidsteel material after subsequent heat treatment cycles for binder removal, partial sintering. and liquid chase infiltration. The microstructure of SLS samples heated to 1120 C for 3 h in 30H(2)-70N(2) atmosphere at 2 K min(-1) consisted of a Mixture of austenite, M23C6, and Cr2N phases, Subsequent infiltration of the above sample with bronze at 1050 C for 2 h in 30H(2)-70N(2) atmosphere at 2 K min(-1) produced similar phases together with an additional chi(Cu-Sn) phase. The mechanical tensile fracture strength of the partially sintered part increased ten times after infiltration with bronze. However, the fracture behaviour is found to be different between the samples subjected to various heat treatment cycles, The sample heated after the first cycle showed fracture along the necks between stainless steel particles, whereas the infiltrated sample showed fracture along the bronze infiltrant.
Original language | English |
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Pages (from-to) | 251-254 |
Number of pages | 4 |
Journal | Powder Metallurgy |
Volume | 45(3) |
Publication status | Published - 1 Oct 2002 |