Thixoforming of Stellite Powder Compacts

Journal Article · Sat Apr 07 04:00:00 EDT 2007 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2729676· OSTI ID:21056978

Hogg, S C ^[1]; Atkinson, H V ^[2]; Kapranos, P ^[3]

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1. Institute of PolymerTechnology and Materials Engineering, Loughborough University, Loughborough, LE11 3TU (United Kingdom)
2. Department of Engineering, University of Leicester, University Rd., Leicester LE1 7RH (United Kingdom)
3. Department of Engineering Materials, University of Sheffield, Mappin Street, Sheffield S1 3JD (United Kingdom)

Thixoforming involves processing metallic alloys in the semi-solid state. The process requires the microstructure to be spheroidal when part-solid and part-liquid i.e. to consist of solid spheroids surrounded by liquid. The aim of this work was to investigate whether powder compacts can be used as feedstock for thixoforming and whether the consolidating pressure in the thixoformer can be used to remove porosity from the compact. The powder compacts were made from stellite 6 and stellite 21 alloys, cobalt-based alloys widely used for e.g. manufacturing prostheses. Isothermal heat treatments of small samples in the consolidated state showed the optimum thixoforming temperature to be in the range 1340 deg. C-1350 deg. C for both materials. The alloys were thixoformed into graphite dies and flowed easily to fill the die. Porosity in the thixoformed components was lower than in the starting material. Hardness values at various positions along the radius of the thixoformed demonstrator component were above the specification for both alloys.

• OSTI ID: 21056978
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 907; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COBALT
GRAPHITE
HARDNESS
HEAT TREATMENTS
LIQUIDS
MANUFACTURING
MICROSTRUCTURE
POROSITY
POWDERS
PROCESSING
PROSTHESES
SOLIDS
SPECIFICATIONS
STELLITE 6
THIXOTROPY