Deformation enhanced liquid phase sintering (DELPS): A study on the use of partial adiabatic melting during powder consolidation
2002 (English)In: Journal of Materials Processing Technology, ISSN 0924-0136, E-ISSN 1873-4774, Vol. 127, no 2, p. 159-164Article in journal (Refereed) Published
Abstract [en]
The presence of a liquid phase enhances the pore closure of a porous body, which is used in liquid phase sintering (LPS). During LPS, a substantial grain growth may occur by coalescence or Ostwald ripening, thus a short time in the liquid state is advantageous. Furthermore, it has been shown that during the initial stage of LPS, agglomerates are disintegrated and a significant reduction of grain size occurs. Heavy deformation causes an adiabatic temperature increase, which may result in a partial melting of the powder. Short-time duration deformation-assisted LPS, so called deformation enhanced LPS (DELPS), may thus be a suitable route for the fabrication of difficult-to-form materials. The present study is a feasibility test of DELPS. Three different types of materials were tested. The first type was an Al-Si with the possibility to form a large fraction of liquid phase. The second type was a W-based powder mixture yielding a low fraction liquid. The third type was a Ni-Al powder mixture exhibiting an exothermal behaviour when reaction occurs. The powders were hot compacted in a flexible die allowing large deformations. The specimens were examined and the composition of the phases were analysed. All of the samples, but one, showed near full density (>98%). Evidence of melting was found and in the W-base and the Ni-Al powder mixtures, and reaction had occurred in the Ni-Al mixture. © 2002 Elsevier Science B.V. All rights reserved.
Place, publisher, year, edition, pages
2002. Vol. 127, no 2, p. 159-164
Keywords [en]
Deformation enhanced liquid phase sintering, Partial adiabatic melting, Powder consolidation, Compaction, Consolidation, Deformation, Density (specific gravity), Grain growth, Melting, Phase composition, Liquid phase sintering (LPS), Sintering
National Category
Materials Engineering
Identifiers
URN: urn:nbn:se:hj:diva-16652DOI: 10.1016/S0924-0136(02)00118-8OAI: oai:DiVA.org:hj-16652DiVA, id: diva2:454602
2011-11-072011-11-072017-12-08Bibliographically approved