Using a 120# white corundum PVA grinding wheel for precision grinding, and an electroplated diamond roller for arc finishing, the disc can be precisely ground and polished at the same time, the size and surface roughness of the disc can reach ΦA=50(±0.03mm) and Ra=0.4μm respectively.
Theoretical and experimental studies show that PAL_(MS) decoder possesses the following abvantages:(1) For the production of ultrasonic glass delay-lines used in this decoder, precision grinding process is not needed.
A systematic study of the changes in composition and structure of surface layers due to the thermo-chemical and thermo-mechanical affects among the wheel, the workpiece and the grinding fluid during precision grinding on carburized steel 20CrNi2 MoA railway bearing has been conducted.
The results from grinding process with the spindle mounted on a precision grinding machine show that the accuracy of finished surface of workpiece can be up to the required machining quality, and the fine grinding efficiency is close to the industrial application level.
The bending strength of the samples after wire EDM cutting, rough grinding, finishing grinding, coating once with Al 2O 3 sol and coating twice with Al 2O 3 sol is tested and compared. The cause of the surface modification is analyzed by observing SEM photographs of surface and section of the samples coated once and twice with Al 2O 3 sol.
It is shown that bending strength rises in the order of linear cutting,rough grinding,finish grinding,polishing,thermal treatment,coating once with Al 2O 3 sol,coating twice with Al 2O 3 sol,coating with composite Al 2O 3-SiO 2 sol.
By using the elastic thread positioning shaft for ghnding plungersinstead of the thread plug, the rough grmnding allowance can be decreased by 15% ~ 20%, the amount of chrome platedcan be decreased by 20% ~ 30%, and the finish grinding allowance can be decreased by about 30%.
It is showed that the laser power,scanning speed,defocusing amount and coating layer thickness have different influence on thickness,overlap joint and surface status of the hardened layer respectively,with optimized laser surface alloying processing parameters,a uniform alloyed coating with thickness of 0.40～0.60mm(after finish grinding)and surface hardness over 78HRA is obtained.
to control the wear of grinding wheel and the thermal deformation of the technological system, and adopting flow line production method for rough grinding、finish grinding and seper-finishing are the efficient way to guarantee the bearing quality with random assembling method.
Attainment of relative densities of up to 97% in parts from columbium carbide powder is only feasible when fine comminution of the powder, cold compacting, and sintering at temperatures not exceeding 0.6 Tmelt.
1.Fine comminution causes graphite to lose its compactibility.
Theoretical and experimental analysis on super precision grinding of monocrystal silicon
Determination of the scheme of precision grinding compensation on the radome
Controlled wear of vitrified abrasive materials for precision grinding applications
The study of bonding hard materials such as aluminium oxide and cubic boron nitride (cBN) and the nature of interfacial cohesion between these materials and glass is very important from the perspective of high precision grinding.
Ductile streaks in precision grinding of hard and brittle materials