The invastigation of the effect of sintering heat on microstructure in CoCrMo powder alloy produced via hot pressing technique

In this study, CoCrMo powder metal alloy was produced by means of hot pressingtechnique and this specimens which was produced was investigated as mechanical andmicrostructural. Metal powders added in ratio wt.% 67.5 Co, 27.5 Cr and 5 Mo weremixed as homogen by adding PEG lubricator and balls covered with Cr in a mixer whichcan turn 360 ºC. Then these mixtures were sintered in hot press which have in argonatmosphere at temperature of 750, 800, 850, 900 ºC and pressure of 115 MPa by filling tographite molds. Then this samples producted have done three point bending, fracturesurface, micro hardening, density measurement, microstructure, X-Ray diffractioninvestigation when done necessary metallographic procedure.Experimental studies and the results showed that sintering threatments duringdifferent temperatures increases the bending-extension strenght micro hardening andintensity increases as linearly and the porosity sample linearly decreased except 3thsample. Lumplys occured due to the deposition of microporosity composite caracter ofstructures. The result of this study showed that microstructure investigations observed aslower a result of the sintering temperature of 750 and 800 º C and in subsequent highersintering temperatures observed less porous and better the composite character ofbuildings. region the composite character with flaky were observed precipitation structuresat sintering temperature of 850 ° C . The elemental structures were observed in thisexamples as a result of XRD diffractions. A large number of compounds between Co-Mowere formed as well as increasing the sintering temperature. Due to high meltingtemperature of Cr, Cr has not created the compound and were always observed inelemental structure. In this study, produced CoCrMo powder alloys via hot pressingtechnique in different sintering temperatures were observed to have been at the bestsintering temperature on microstructure and mechanical properties at 900 º C.Key Words: Hot pressing, powder metallurgy, microstructure, CoCrMo superalloy