Tungsten carbide coatings are often applied to improve surface properties such as wear, high temperature degradation, and corrosion resistance. Zirconia coatings have also been used extensively in various industries due to their excellent tribological and insulation properties combined with high stiffness. It is speculated that adding zirconia to tungsten carbide may result in a coating with combination of excellent thermal and mechanical properties of constituents. In the current study, a powder mixture of 50 wt. % WC-Ni and 50 wt. % ZrO 2 -Y 2 O 3 deposited on a low carbon steel substrate using atmospheric plasma spray technique. The microstructural evolution of deposited sample was investigated. Splat boundaries, micro cracks, pore morphology conversion, and grain growth mechanism were elucidated comprehensively. Results indicated a good adhesion between two different major components. No porosity formed due to mismatch between zirconia and tungsten carbide. This study pays special attention to the dependency of the microstructural characteristics to the phase distribution within the coating.

With further technology scaling, it becomes increasingly challenging for conventional methods of failure analysis (FA) to identify the cause of a failure. In this work, we present three case studies on the utilization of advanced nanoprobing for SRAM circuit analysis and fault identification on 20 nm technology node SRAM single bit devices. In the first 2 case studies, conventional failure analysis by passive voltage contrast (PVC) failed to identify any abnormality in the known failed bit. In the third case study, an abnormally bright PVC was observed by PVC inspection. In all three case studies, static noise margin of the SRAM bits during hold and read operations were performed to understand the circuit behavior of the failed bit cell. Next, nanoprobing on the individual transistors were performed to determine the failing transistor within the bit and the possible cause of the failure. TEM analysis was performed to identify and verify the failure mechanism.

Agglomerate sintered and blended NiCrAlY-Y 2 O 3 cermets were prepared from NiCrAlY and Y 2 O 3 powders by two process routes. The particle morphologies and powder characteristics of both cermets feedstock using for thermal spraying were investigated. Both types of NiCrAlY-Y 2 O 3 cermets and one commercial CoCrAlY-Y 2 O 3 cermets were HVOF thermal sprayed onto the stainless steel substrate to obtain coatings having a thickness about 100 microns. Porosity and thermal shock resistance of coatings were examined. Four thermal sprayed coatings were comparatively evaluated build-up resistance by contacting reaction with MnO, Fe 3 O 4 powders and manganese bearing carbon steel statically at high temperatures. The agglomerate sintered NiCrAlY-Y 2 O 3 coatings have good resistance to manganese oxide build-up but bad resistance to iron oxide build-up. The agglomerate sintered cermets coating has better build-up resistance than blended cermets coating.

This article examines the splat shape at off-normal angles in plasma spray and investigates the relationship between the splat elongation ratio and the spray angle on various spray materials and particle sizes. The applicability of the model to the experimental results is investigated. In this study, six powders of aluminum, copper, and nickel as metal spray materials and of alumina, titania, and zirconia as oxide materials were sprayed. It was observed that the model agreed well with the elongation ratio of the experimental results in the range between 90 and 30 degree. The model values were over-estimated than the practical results at spray angles less than 15 degree.

The transitional behavior of the splat pattern of Ni particles sprayed on a flat substrate was investigated. Based on Auger analysis and SEM observation, it was confirmed that the splashing was formed not by material flowing on the substrate surface from the impingement center to the periphery, but by jetting away from the central disk. Observations of etched splat surfaces revealed that the bottom portion of the central disk solidified rapidly after impingement, and it was also confirmed, based on the direction of the splash pattern, that the splashing was caused by stumbling due to some type of deterrent to liquid flow, such as poor wettability at the flow tip or initial rapid solidification of the splat. The drastic change of the splat pattern near the transition temperature seems to occur when the Weber number of the liquid flow coincides with some critical value.