Papers by Author: W.P. Du

Abstract: Potassium Titanium Oxide Phosphate (KTP) is a new nonlinear frequency-conversion crystal. It has chemical stability, high nonlinear coefficient, high damage threshold, easily-polished surface, and a broad transparency range. It is be used in solid green laser with medium and low power widely. The requirement for surface roughness is less than 1nm.In this paper, the removal rate and surface roughness are discussed with different velocity, pressure and size of abrasive powder. In order to satisfy the requirement, new polishing techniques with ultra-precision plane polishing machine (Nanopoli-100), and fine AL2O3, SiO2 powders are proposed in this study. The final surface roughness of the KTP is less than 1nm.The machining process and characteristics are also indicated.

Abstract: STAVAX ESR（S-136）is a type of high stainless steel, used in precision mould widely . It has fine anticorrosion, polishing-alike, wearable，good process capacity and quench stability. To obtain the smooth surface of STAVAX ESR, the material removal mechanism in the paper is discussed. The experiment is processed on the ultra-precision plane polishing machine (Nanopoli-100). The experiment processes are as follows. Rough lapping and Ultra-precision lapping: the material of lapping pads is cast iron. #1000Al203 (10wt%) abrasive powders are used in rough lapping. Finally, surface roughness is 62nm. In ultra-precision lapping, abrasive powders are for #4000Al203（10wt%）. Removal rate is 1nm with linear velocity 8.6m/min, pressure 3.65MPa. After 4000 rounds, surface roughness is 35nm.Ultra precision polishing: The super smooth surfaces of STAVAX ESR（S-136）with 5nm roughness have been obtained by adopting SiO2(> 30wt%) slurry and soft tin polisher in the experiment.