MS, University of Cincinnati, 2002, Engineering : Materials Science
The objective of this study is to develop copper matrix composite for electrical contact application. Copper matrix composites with refractory material reinforcement have properties such as high electrical conductivity and high wear and erosion resistance, which make them a preferred candidate for electrical contact application. The approaches for making of these composites have been different not only in the selection of the type, size and shape of the reinforcements but also in the steps involved in its making. This study focuses on the particulate reinforced metal matrix composites produced by using the liquid metal infiltration process. The process consists of the injection and subsequent solidification of liquid copper within the interstitial spaces of a porous tungsten carbide preform. The two critical parameters of this process are temperature and pressure. While the temperature parameter is critical for the viscosity of the liquid metal to be sufficient and the superheat considerations, the pressure parameter plays an important role in forcing the liquid metal into the porous preform. The effect of temperature variation on the microstructure and properties of the composite has been discussed. The infiltration process in this study is without the application of any pressure with the capillary forces providing sufficient pressure drop at the infiltration front. The reliance on the capillary forces brings to fore the wettability aspect of the process. The need of favorable wetting behavior between the constituents cannot be overstated. Copper-tungsten carbide composites were prepared in a very short time using the infrared heating process. The composite produced has a significant increase in the hardness value (360-370 VHN) as compared to copper (170 VHN). The resistivity value of the composite (5.4 x 10 -6Ω-m) is very close to the resistivity value of copper (1.7 x10 –6Ω-m). The density value as close as 97-98% of the theoretical density value has been achieve (open full item for complete abstract)
Committee: Ray Y. Lin (Advisor)
Subjects: Engineering, Materials Science