Vacuum sintering of water-atomised HSS powders with MoS2 additions

Molybdenum disulphide (MoS2) is a well-known and widely used solid lubrican t. As such, it might also be a useful addition in the production of composi te self-lubricating high-speed steel parts which are used in different anti -wear applications. MoS2 might also have a favourable influence on the synt hesis of sintered HSS. In view of this, the compressibility and the sintera bility of M3/2 and M35 types of HSS powder mixtures with MoS2 additions wer e investigated. In this paper, the influence of MoS2 on the densification d uring vacuum sintering of selected HSSs is presented. It has been establish ed that the densification of HSS-MoS2 powder mixture proceeds by a combinat ion of a reactive and super-solidus liquid-phase sintering process. The add ed MoS2 reacts with the steel matrix, enhancing densification. Complex sulp hides (Cr, V, Fe)S are formed, whilst the Mo enriches the steel matrix and forms complex carbides with other alloying elements. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.