The hot tearing susceptibilities (HTS) of some AA7×××alloys, AA7050, AA7055, AA7085 and AA7022 were evaluated with constrained rod casting (CRC). Thermal contraction behaviors during solidification were measured as well in a T-shaped setup. The results showed that alloys with HTS from high to low were AA7055, AA7085, AA7050 and AA7022. Zn content in 7××× aluminum alloys seemed to play a major role with respect to the HTS index. Remarkable differences could be seen on thermal contraction behaviors within solidification range for each alloy. The rate and amount of thermal contraction for AA7055 was most prominent, followed by AA7085 and AA7050, while contraction curve of AA7022 was very flat together with least amount of thermal contraction. There was a well consistency between the amount of thermal contraction and HTS. Despite complex interactions of many variables in the formation of hot tear, thermal contraction behaviors within solidification range could give a quick evaluation of hot tearing susceptibility.

A active Cl-doping for photoluminescent ZnS powder has been carried out by thermal decomposed AlCl3·6H2O in a quartz tube. Room temperature photoluminescence of the Cl-doped ZnS powder has been investigated using a photoluminescence spectrometer with 365 nm excitation wave length. A strong blue photoluminescence with maximum peak about 450 nm and green photoluminescence with maximum peak about 500 nm can be observed if the doping temperature in range of 800 ~ 900 °C and 1100 ~1200 °C, respectively. The structural characterizations of the Cl-doped ZnS powders were performed with X-ray diffraction (XRD) and the mechanism of photoluminescence was preliminarily discussed.

For the existing drawbacks in the crucible rotation vertical drop method, the control system is improved. Developed a new control system, overcome the drawbacks of original crystal growth control system, and improve the control precision, and simplify the programming program. Use to prove it reliable, stable, a more perfect crystal growth control system. Now has been formally put into use.

For the existing drawbacks in the crucible rotation vertical drop method, the control system is improved. Developed a new control system, overcome the drawbacks of original crystal growth control system, and improve the control precision, and simplify the programming program. Use to prove it reliable, stable, a more perfect crystal growth control system. Now has been formally put into use.

High alumina foam ceramics products with low density, high specific surface area, low thermal conductivity, corrosion resistance and other excellent physical and chemical properties are suitable for chemical, metallurgy and other related fields [1-4]. Alumina foam ceramics that compression strength increased by 200%, was prepared by Rizwan Ahmad through impregnation process using foamed rubber [5]. However foamed rubber was expensive and could be decomposed creating poisonous gases at high temperature. Zhou l z [6] prepared mullite porous ceramics with high strength by gel-casting method. Gel-casting is an effective method for preparation of ceramics products with large size and complicated shape. Fiber reinforced dense ceramics composite materials with excellent performance have been studied widely [7-10], it is also an important issue to adequately investigate the reinforcement of porous ceramics with fiber.