Influence of forms and final size of abrasive surface finish

Abstract

Purpose. For plasma spraying protective coatings flame tube GTE attempt to resolve issues related to the selection of abrasive material, its use of technology to create the required roughness on Nickel VJ-98. From a large number of abrasive materials most widely used for obtaining corundum received roughness (AhO3) and silicon carbide (SiC). Each of these materials has its advantages and its disadvantages. It is necessary to establish patterns of influence of the shape and size of the abrasive selected the final roughness treated by coating the surface and indicate ways to further improve performance strength and adhesion of coatings. Methods. Tests carried out on the sheet blanks nickel alloy VJ-98 with a thickness of 3.0 to 11.0 mm, size 50 x 50 mm. The roughness created air training. With this method, the kinetic energy of abrasive material conveyed an air jet pressure of 4-5 atmospheres. The value of roughness measured on the instrument Talysurf 5-20 (Taliserf 5-20), the company «TAYLOR - HOBSON», UK. GOST 2789-73. Results. Established in position to supply both synthetic materials electrocorundum "a" Al2O3 and carborundum - silicon carbide SiC. with sharply angular shape grains. Each of abrasives creates roughness with the presence of acute angle peak at a value of microscopic roughness Rz within 56-60 microns. When these treatments varies appearance abrasive particles and their size. If corundum during further processing does not change its size, but only their rounds sharp angular edges, the silicon carbide while maintaining sharp angular shape, crushed into smaller particles, which decreases the processing height of asperities on the treated surface. Repeated use abrasives inequality vary the height and the surface becomes smoother, which should lead to a reduction in grip strength sublayer of the basic material. Our results revealed that the particles after the first training air change shape, size and their distribution. If silicon carbide in a position to supply a sharply angular shape and particle size in the range of 1-2 mm, after the first air training its particle size is reduced to 0.5-1 mm in storage acute angular shape Aluminium oxide after the first air training basically keeps the size of particles, but they become more rounded shape. The study treated surfaces suggests that the comparison of corundum and silicon carbide preference must pay first, but limit it to quadruple use. Scientific novelty. Obtained new scientific data on the effect of form and size of the abrasive on the final machined surface roughness. The practical significance. Found materials for abrasive machining nickel alloy VJ-98, their roughness parameters, patterns influence the form and size of the abrasive selected the final machined surface roughness and the ways of improving adhesion performance coatings