Effects of temperature on the removal efficiency of KDP crystal during the process of magnetorheological water-dissolution polishing

Abstract

As a kind of important nonlinear optical element, KDP crystal has great demand in the inertial confinement fusion system. Based on the dissolution mechanism of solid materials, the factors that affect the material removal rate of KDP crystal in magnetorheological (MR) water-dissolution polishing are investigated to improve the machining efficiency. It is found that the material removal rate is proportional to the product of the saturation concentration and diffusion coefficient, and the relationship between the removal efficiency and the temperature meets the unilateral Gaussian function. Polishing experiments are carried out on a magnetorheological finishing (MRF) machine with self-designed MRF fluid heating devices. The experimental results show that practical efficiency-temperature curve is consistent with the theoretical curve, and the maximum machining efficiency increases by about 50% with the rise of temperature from 294 to 302 K. Meanwhile, when the MR fluid temperature is lower than 308 K, the crystal surface quality and surface roughness in different processing temperatures have no remarkable difference with constant crystal temperature (294 K). This research indicates that it is feasible to drastically improve KDP crystal MRF efficiency by controlling the processing temperature.

The Growth and Characterization of KH2PO4 and CuSO4·5H2O Crystals with Large Sizes for Undergraduate Education

“…The driving force of crystal growth is the supersaturation of the solution. The detailed experimental procedures are described as follows: According to the solubility curve in the literature, , students performed a simple calculation to figure out the number of grams of KDP/CSP reagents that were required to configure the 150 mL saturated solution at 30–35 °C (approximate room temperature). The KDP/CSP powders were dissolved in 150 mL of deionized water at 60 °C and stirred for 20–30 min to get a homogeneous solution. Subsequently, this solution was filtered through a funnel with a 50 μm membrane and then evenly transferred to three beakers labeled 1 , 2 , and 3 , respectively.…”

“…According to the solubility curve in the literature, , students performed a simple calculation to figure out the number of grams of KDP/CSP reagents that were required to configure the 150 mL saturated solution at 30–35 °C (approximate room temperature).…”

Study of the Formation of Precursor Clusters in an Aqueous Solution of KH2PO4 by Small-Angle X-ray Scattering and Molecular Dynamics

“…As the solvent for the KDP crystals, Millipore ultrafine water was used (water resistance 18 MΩ × cm). The concentration of KDP in an aqueous solution was 501 mg/mL, which corresponds to the saturation temperature of the KDP solution at 60 • C [7]. The crystals were dissolved in water at 80 • C in a thermostat.…”

The using of x-ray grazing incidence diffraction technique in KDP surface characterization

“…As key frequency inverter, the bulk single-crystal KDP has been widely used in inertial confinement fusion (ICF) facility, such as SG-III Laser Facility in China, the National Ignition Facility (NIF) in USA and Laser MegaJoule (LMJ) in France [4][5][6]. However, since the bulk single-crystal KDP is fragile, various defects usually appear in the KDP surface layer, for example, laser-induced [7][8][9], cutting-induced [10][11][12], polishing-induced [13][14][15][16] and dissolutioninduced defects [17][18][19]. What's more, it is supposed that these surface layer defects obviously weaken the laser-induced damage threshold (LIDT) of high-energy laser systems.…”