Research On The Densification Of W-30wt.%Cu Powders By Hot Extrusion And Rolling

At present, the demands of W-Cu composite products are more and morewidely. However, W and Cu are insoluble, they can only form pseudo-alloy, so thatit is difficult to produce the W-Cu composite material with high density byconventional metallurgical method.In this paper, the W-30wt.%Cu composite material was fabricated by hotextrusion and rolling of W-30wt.%Cu powders that was made by spray-dryingmethod in steel cups. The temperature of the first hot extrusion is1050℃、1100℃、1150℃and1200℃, and the temperature of hot rolling is850℃、900℃、950℃and1000℃, respectively, while the temperature of the second hot extrusion is1050℃.The bar and sheet obtained have good properties.The conductivity, hardness and compression properties of W-30wt.%Cu compositebar by hot extrusion were analyzed and the influence of temperature onmicrostructure and performance were studied. It is found that the distribution of fineW phase and Cu phase in the W-30wt.%Cu composite powder made byspray-drying method is uniform and no impurities were found. By cold pressing, therelative density can reach71.4%, and after hot extrusion at1100℃, good propertiesare obtained, which are relative density of91%, conductivity of45.184%IACS,hardness of269.96HV and yield stress of120MPa。After the second hot extrusion orhot rolling, the relative density is increased to95%, and the hardness andconductivity are also improved.The change of wall thickness of steel cup during processing is studied, and it isfound that the wall thickness is gradually becoming thinner. So if a proper originalwall thickness is selected, the final thickness would become the minimum, which isimportant for actual production, because it can reduce the subsequent processing.