3results about How to "No defects" patented technology

The application relates to the field of advanced structural ceramics, and particularly discloses a gel injection molding method for preparing high-performance silicon nitride ceramics and a preparation method thereof. Raw materials include beta-SiN submicron powder 75 parts, YO submicron powder 8 parts, TiC submicron powder 5 parts, AlO superfine powder 5 parts, ZrO submicron powder 2 parts and wollastonite 5 parts in terms of mass ratio, a complex whisker regulator and an entry liquid are used, and ceramics are prepared through gel injection molding, dehydration, degreasing and gas pressure sintering. The grain morphology and interface combination are optimized through the whisker regulator, the slurry dispersion and the green body uniformity are improved through the entry liquid, and the product has a density greater than or equal to 99%, a Vickers hardness greater than or equal to 1700HV and a bending strength greater than or equal to 930MPa through 1700-1850 DEG C. gas pressure sintering, and the product has high density, high hardness, high toughness, wear resistance, corrosion resistance and long service life.

This invention relates to a method for manufacturing high-surface-quality steel wire for chain pins, comprising the following steps: steel smelting → continuous casting → heating of continuously cast billets → billet preparation → flaw detection and grinding of intermediate billets → wire rod heating → high-pressure water descaling → annealing → pickling and phosphating → wire drawing → finished product. The method employs a two-stage forming process, with a high compression ratio in billet rolling, wire rod rolling, and wire drawing, which reduces the impact of defects in the raw material on the finished product. During billet rolling, flame cleaning is used to remove surface defects from the billet. Before wire rod rolling, the intermediate billet undergoes surface flaw detection and full grinding to ensure a defect-free surface. Eddy current testing and high-reduction-ratio wire drawing ensure the depth of surface defects in the steel wire, and the high-reduction-ratio drawing results in higher wire hardness, improving the cutting performance for pin processing. Finally, the steel wire used in pin production can control the single-sided grinding residue to within 0.03mm, significantly improving material yield and surface defect compliance. Simultaneously, the high wire hardness provides excellent cutting performance for pin processing.

This invention provides a metal electroplating composition comprising: a sulfur-containing compound, a tin salt, a silver salt, an acidic electrolyte, a surfactant, a brightener, an antioxidant, a pH adjuster, and water. The sulfur-containing compound is a compound of formula (I): wherein R1 is selected from primary, secondary, and tertiary amino groups; R2 is selected from straight-chain alkyl and branched-chain alkyl groups; R3 is selected from straight-chain alkyl and branched-chain alkyl groups; and R4 is selected from hydrogen and alkyl groups. Using the above technical solution, electroplating under high current density conditions can achieve the following technical effects: no pores or defects, low impurities in the plating layer, excellent plating uniformity, dense structure, and low surface roughness. The metal electroplating composition has good plating solution stability and plating uniformity, and can obtain consistently good appearance and film thickness uniformity of the plating film. It has good industrial application value.