This study investigates the phase stability and thermophysical properties of Y 2 O 3 and Yb 2 O 3 co-doped SrHfO 3 (SHYY) powder and bulk material along with the phase stability and microstructure evolution of as-sprayed SHYY coatings during annealing. The powder was synthesized by a solid-state reaction at 1450 °C, showing good phase stability up to 1400 °C. Dilatometry measurements revealed no abnormal changes in the coefficient of thermal expansion over a temperature range of 200-1300 °C. The thermal conductivity of the bulk material was found to be 16% lower than that of SrHfO 3 . Free-standing SHYY coatings deposited by air plasma spraying were also tested. The coatings consisted of SHYY and a minor amount of secondary phase Yb 2 O 3 and exhibited good phase stability during heat treatment at 1400 °C for 288 h. Coating samples examined after 216 h still exhibited a columnar microstructure.

By means of homemade ultrasonic arc spraying equipment patented, under the condition of the optimum arc spraying parameters, TiAl alloy coatings were manufactured on the aluminum alloy (LY12) matrix surface. The ultrasonic arc spraying forming process and microstructure of TiAl compounds alloy coatings were investigated by the color metallurgical microscopy, SEM, XRD, EPMA and chemical composition quantitative analysis (ICP). The results showed that TiAl compounds composite coatings can be synthesized by ultrasonic arc spraying system, the coatings possess typical lamella character, consist of TiN (or TiO), TiAl, Ti 0.7.1.1 Al(N,O), Ti 2.4 Al(N,O), Ti 2.4 Al and aluminum alloy solid solution.

By use of homemade arc spraying system patented, which could make melted metal droplets atomized fully and make its flying velocity achieve ultrasonic velocity, TiAl alloy coatings were manufactured on the aluminum alloy (LY12) substrate surface. The slide wear resistance of TiAl alloy coatings was investigated. The effect of spraying parameters, coatings' chemical composition and microstructure on the slide-wear resistance of coatings was examined. Then the slide-wear mechanism of the coatings was discussed. The results showed that the slide wear resistance of TiAl alloy coatings by ultrasonic arc sprayed is 17 times higher than it of the aluminum alloy (LY12) substrate under the condition of dry slide-wear.

This paper describes a new technique for identifying defects on integrated circuit. This technique detects the noise content in light emitted from defect sites. The purpose of this technique is to determine which of many light emission sites represent a defect and which represent normal devices. It reports the first phase of studies to evaluate the feasibility and potential effectiveness of this technique. The feasibility of this technique has been demonstrated by simultaneously monitoring electrical noise and the noise in the light emitted from a gallium arsenide light emission diode (LED) and a bipolar transistor. The paper will present the methodology and apparatus used to detect and analyze the noise in light emission.