Papers by Author: Yong Ping Ai

Abstract: The rules of various factors influence the gypsum-based composite material(GBCM) performance are studied, using orthogonal experiment from the material components, retarder dosages and different w/c ratio. The results show that the strength and softness coefficient of GBCM are obviously higher than that of pure gypsum. The Portland cement can markedly accelerate the coagulation of GBCM, when its mixed amount is 10%-15%, it can enhance the strength and softness coefficient of GBCM, but overdosage will cause fall of the strength and softness coefficient of GBCM. The phosphate retarder changes the growth habit of dehydrate gypsum crystal and the aperture distribution of GBCM, which correspondingly makes the crystal thickening and the pore structure deteriorating and ultimately leads to reduce the strength

Abstract: This paper aims to study the effects of rare earth Cerium addition on mobility, solidification shrinkage, casting microstructure and hot tearing tendency of Al-4.5Cu alloy. Results show that by adding appropriate rare earth Cerium into the Al-4.5Cu alloy, the viscosity of liquid metals can be reduced, the mobility of alloy can be increased, and the shrinkage during the solidification of liquid metal can be reduced. Further more, as the tendency of alloy dendrite is inhibited and the microstructure of the casting alloy is improved, the alloy can be purified, its thermal conductivity can be enhanced, and the hot tearing tendency of it can be decreased remarkably. It proves that when rare earth Ceriumaddition in Al-4.5Cu alloy is 4w%, the mobility of Al-4.5Cu alloy will be the maximum, and its volume shrinkage will be the least. Meanwhile, the grains of alloy are refined and round. The alloy also shows the lowest hot tearing tendency.

Abstract: The semi-solid slurry of AlSi7 alloy was prepared by near-liquids cast processing. The effects of different content of RE on the cast performance and the semi-solid remelting performance in AlSi7 alloy was researched. The results indicated that adding RE will widen the AlSi7 alloy solid-liquid two-phase zone temperature and refine the grains, silicon will obvious metamorphoses. The best amount of RE is about 0.5%. Its semi-solid remelting organization is equilateral globular grains.