Spark plasma sintering of Ti-diamond composites. Issue 9 (15th June 2019)

• Record Type: Journal Article
• Authors: Mallik, Awadesh Kumar; Das, Mitun; Ghosh, Sumana; Chakravarty, Dibyendu
• Is Part Of: Ceramics international. Volume 45:Issue 9(2019)
• Page Start: 11281
• Page End: 11286
• Publication Date: 2019-06-15
• Subjects: Titanium matrix composites -- Spark plasma sintering -- Raman spectroscopy -- X-ray diffraction -- Hardness; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2019.02.204
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: Laser melting of Ti-diamond powders have been found to enhance the mechanical properties of technologically important material like titanium matrix composite (TMC). However, there is a tendency for the diamond to graphitise during the laser melting process. In order to overcome this fallacy, an alternate processing route, namely, spark plasma sintering (SPS) was adopted for fabricating the TMC's. A wide range of powder compositions varying from 5 to 50 wt percentage of diamond (0.25 μm) was added to titanium and the as-sintered compacts were investigated by X-ray diffraction (XRD), Raman spectroscopy, Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDAX). In-situ phase changes were observed with increase in diamond content in the composition. Addition of diamond upto 15% led to formation of a mixed Ti and TiC phase in the matrix. Interestingly there was no trace of metallic titanium with 20% diamond in the composition and a TiC-only phase was observed, corroborated by an abrupt increase in hardness to 1076 Hv. At even higher diamond percentages there was trace of unreacted carbon along with TiC. This work indicates, for the first time, the use of SPS as an alternate route for fabricating in-situ TMCs with enhanced mechanical properties.