Powder injection moulding of cemented carbides: Feedstock preparation and injection moulding
Keywords:
powder injection moulding, cemented carbides, tungsten carbide-cobalt, PEG/PMMA composite binderAbstract
A composite binder system, successfully developed earlier for powder injection moulding of stainless steels, CoCrMo and NiCrSiB alloys, has been adapted for tungsten carbide-cobalt (WC-Co) cemented carbides. The binder consists of a major fraction of polyethylene glycol (PEG), which can be removed rapidly by leaching with water, a minor fraction of a finely dispersed polymethyl methacrylate (PMMA), which retains rigidity of the components and sometimes with stearic acid (SA) to act as a lubricant. The adjustments made to powder characteristics, binder compositions and process parameters to achieve successful injection moulding are reported. Feedstocks containing a powder loading of the WC-Co up to 60 vol% can be moulded successfully. The moulded specimens had good green strength, in the range 12-17 MPa for three point bend tests.Downloads
References
German, R. M. and Bose, A. 1997. Injection Moulding of Metals and Ceramics, Princeton, NJ. : Metal Powder Industries Federation.
Alcock, J. and Stephenson, D. The Powder Injection Moulding Process. (Online) Available at : http://www.azom.com/ Details.asp?ArticleID=1080 (accessed 15/3/2007).
Upadhyaya, G. S. 1998. Cemented Tungsten Carbides : Production, Properties, and Testing, Westwood, NJ. : Noyes Publications.
Anwar, M. Y., Messer, P. F., Ellis, B. and Davies, H. A. 1995. Injection moulding of 316L stainless steel powder using novel binder system. Powder Metall., 38(2) : 113 - 119.
Omar, M. A., Davies, H. A., Messer, P. F. and Ellis, B. 2001. The influence of PMMA content on the properties of 316L stainless steel MIM compact. J. Mater. Process Tech. 113 : 477-481.
Newell, M. A., Davies, H. A., Messer, P. F. and Greensmith, D. J. 2005. Metal injection moulding of scissors using hardenable stainless steel powders. Powder Metall. 48(3) : 227-230.
Bhero, S. W. 1999. Powder injection moulding of Co-Cr-Mo alloy and type 440 martensitic stainless steels. Doctoral The University of Sheffield.
Wong, S. H. 2003. Injection moulding of anorthite/mullite porcelain. Doctoral The University of Sheffield.
Chuankrerkkul, N. 2006. Powder injection moulding of WC-Co hardmetals using a PEG/PMMA binder. Doctoral The University of Sheffield.
Hamburg, M. and Young, P. 1994. Statistical Analysis for Decision Making. Fort Worth, TX. : The Dresden Press.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2017 Journal of Metals, Materials and Minerals
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Authors who publish in this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgment of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgment of its initial publication in this journal.