Papers by Author: Yuan Sheng Cheng

Abstract: A new procedure, thixo-die-forging of ceramics/metal composite in the pseudo-semi-solid state, has been proposed based on powder metallurgy combining with the semi-solid processing of metal. The cup-shaped parts of Al/Al2O3 composite are processed with thixo-die-forging. By metallographic analysis and performance tests, the results show that microstructures are compact, grains are fine and mechanical properties are excellent. The bend strength and fracture toughness of 37vol.%Al/Al2O3 are about 430-690MPa and 8.5-16.8 MPa•m1/2 respectively. Comparing with those of the reaction in situ and high temperature oxidation procedures, the bend strength increases by 50% and 80%, and fracture toughness increases by 29% and 55%, respectively. The results also show that the processing parameters, such as temperature and pressure have great influences on the properties. Thixo-die-forging in the pseudo-semi-solid state can prepare Al/Al2O3 composite with high performance.

Abstract: In this paper the authors propose a new technology for high volume fraction ceramic/metal composites—pseudo-semi-solid thixoforging, based on metal semi-solid process combing with traditional powder metallurgy technology, and explain the differences with other technologies and characters in detail. At the same time the authors prepare the cup shells with high volume fraction Al2O3/Al composite by this technology. It proves that it is feasible for the high volume fraction ceramic/metal composites forming through metallographic analyses and three-point bending tests. The results show that the tough strength and degree of hardness of the samples with certain plasticity are high. It will play a very big role in accelerating the ceramics composites and high melt point materials being used in more fields and tamp the foundation for further studies of this technology.