4 results about "Tetragonal zirconia" patented technology

This invention relates to the field of medical ceramic materials technology, and more particularly to a method for preparing a zirconia-based medical composite ceramic material. The method includes: adjusting the target number of cycles in response to the slurry mixing state, or compensatingly adjusting the spray granulation process parameters based on slurry state parameters; determining whether the current batch of green bodies has a risk of closed pores based on the green body characteristics, and determining an adjustment feature point based on the actual shrinkage rate variation; stopping the sintering heating and adding a holding stage in response to the adjustment feature point, and determining the intermediate holding temperature and the holding stage duration; obtaining the sintered body phase to determine the tetragonal zirconia retention rate, and determining whether the sintering adjustment strategy matches the characteristics of the current batch of slurry based on the sintered body performance; and adjusting the intermediate holding temperature of subsequent sintering processes based on the tetragonal phase retention rate deviation in response to the sintered body performance. This invention improves the performance of ceramic implants by adjusting the sintering temperature curve based on the characteristics of zirconia-based powder.

This application discloses a method for preparing silver-tin oxide electrical contact material for magnetic latching relays, comprising the following steps: depositing indium oxide and tin oxide sequentially on the surface of silver powder by physical vapor deposition to obtain a coated powder, wherein the indium oxide content is 0.3~0.8wt%, the tin oxide content is 8~10wt%, and the balance is silver; mixing the coated powder, yttrium-stabilized tetragonal zirconium oxide, and trace additives to obtain a composite powder, wherein the trace additives are copper oxide or tungsten oxide, and the mass ratio of yttrium-stabilized tetragonal zirconium oxide to coated powder is (2~5):100; hot pressing the composite powder at 25~35MPa to obtain a blank, and holding it at that temperature for 1~2h; hot extrusion processing to process the blank into a rod; multi-pass drawing to produce a wire, and performing intermediate annealing treatment during the drawing process, with each annealing time being 1~2h. The electrical contact prepared by this method has high contact resistance stability and arc erosion resistance.

Provided is at least one among: a zirconia sintered body that exhibits excellent transmission for near-infrared light and can be applied as a cover member that is thinner than conventional cover materials; and a production method therefor.　This yttrium-containing zirconia sintered body has an yttrium content of more than 2.0 mol%, an average grain size of less than 150 nm, and an average birefringence of 0.09 or less, and contains tetragonal zirconia as a main phase.

The present invention provides zirconia media, zirconia bearing balls, and methods for manufacturing the same, with improved wear resistance and durability. [Solution] (a) Made of a sintered body of ZrO2-Y2O3 zirconia, with a Y2O3 / ZrO2 molar ratio in the range of 2.5 / 97.5 to 3.2 / 96.8, (b) Al2O3 content in the range of 0.1% by mass to 30.0% by mass, (c) Contains 90% by volume or more of tetragonal zirconia, (d) Relative density of 95% or more, (e) Average crystal grain size in the range of 0.25 μm to 0.50 μm, (f) Minimum crushing load value Pmin(N) > 600 × D 2.0 (D is the average media diameter), (g) the Weibull coefficient of the crushing load value is 10 or greater, and (h) the coefficient of variation of the media diameter is less than 6%. This is a zirconia-based media.