Ceramic tape-casting slurries are complex systems composed of ceramic powder, solvent, and a number of organic components. Conventionally, the development of ceramic tape-casting slurries is time-consuming and of low efficiency. In this work, combinatorial approaches were applied to screen the ethanol and ethyl-acetate binary solvent based slurry for ceramic green tape-casting. The combinatorial libraries were designed considering the variation of the amount of PVB (Poly vinyl-butyral) binder, polyethylene-400, and butyl-benzyl-phthalate plasticizers, and glyceryl triacetate dispersant. A parallel magnetic stirring process was used to make the combinatorial slurry library. The properties mapping of the slurry library was obtained by investigating the sedimentation and rheological characteristics of the slurries. The slurry composition was refined by scaling up the experiments and comparing the microstructure, mechanical property, and sintering behavior of green tapes made from the selected slurries. Finally, a kind of ethanol-ethyl acetate binary solvent based slurry system suitable for making X7R dielectric ceramic green tapes was achieved.

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Wear tests on the main bearings of 8.5 inch XHP 3 rock bits were performed, from which it is concluded that the way to improve the drilling effectiveness for the rock bits is to set drilling pressure and rotary speed properly, and to develop a new type of grease for rock bits which can bear a higher temperature than conventional grease. In addition, it is also shown that an inexpensive copper alloy can take the place of expensive Ag85Mn15 as an anti-wear material in the bearing, so that the production cost for the rock bits can be reduced.

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