Kinetics of the phase transformation and wear resistance of in-situ processed titanium matrix composites based on Ti-Fe-B

Thermodynamic considerations lead to the conclusion that commercially pure cp titanium and Fe-B are appropriate educts for producing a titanium alloy based metal matrix composite reinforced by an in-situ reaction technique. The aim of the present study was the increase in wear resistance in comparison with the unreinforced cp titanium. Samples were prepared by are melting, by the blended elemental powder metallurgy method and by hot-isostatic pressing. Mossbauer spectroscopy and X-ray diffraction patterns of as cast samples reveal a complete transformation of the educts. Owing to the high cooling rate, metastable phases are found. The sintering parameters using the powder metallurgical route were improved with the aim of increased wear resistance. Depending on the production process and the related microstructure the wear resistance of the Ti-Fe-B cermets was characterized using a pin-on-disc type machine. Under the present conditions wear resistance to the 100Cr6-steel counterpart was observed when the TiB content exceeded 20 vol.%. (C) 1999 Elsevier Science S.A. All rights reserved.