Texture Evolution in U-10Mo Nuclear Fuel Foils during Plasma Spray Coating with Zr

In-house texture measurement using a compact neutron source

In order to improve the instrumental accessibility of neutron diffraction techniques, many emerging compact neutron sources and in-house neutron diffractometers are being developed, even though the precision level of neutron diffraction experiments performed on such instruments was thought to be incomparable with that of large-scale neutron facilities. As a challenging project, the RIKEN accelerator-driven compact neutron source (RANS) was employed here to establish the technical environment for texture measurements, and the recalculated pole figures and orientation distribution functions of an interstitial-free steel sheet obtained from RANS were compared with the results from another two neutron diffractometers well established for texture measurement. These quantitative comparisons revealed that the precise neutron diffraction texture measurement at RANS has been realized successfully, and the fine region division of the neutron detector panel is invaluable for improving the stereographic resolution of texture measurements. Moreover, through selectively using the parts of the obtained neutron diffraction patterns that exhibit good statistics, the Rietveld texture analysis improves the reliability of the texture measurement to a certain extent. These technical research results may accelerate the development of other easily accessible techniques for evaluation of engineering materials using compact neutron sources, and also help to improve the data-collection efficiency for various time-resolved scattering experiments at large-scale neutron facilities.

Study on Preparation of Aluminum Ash Coating Based on Plasma Spray

Ultimate aluminum ash (UAA) was used as the key raw material to prepare ultimate spray powder (USP) via water hydrolysis and ball milling, after which the coating was prepared by atmospheric plasma spray. The flowability of the USP was evaluated by the angle of repose; the process parameters of the coating were determined by orthogonal experiment, and the microstructure and properties of the coating were characterized. The results show that the ultimate spray powder after granulation has an angle of repose less than 40°, which meets the requirements of plasma spray. When the spray current is 600 A, the spray voltage is 55 V, the powder flow rate is 22 g/min, and the main air flow is 33 lspm, the prepared ultimate coating has the best comprehensive performance. The microhardness of the coating is 512 HV, which is about 1.5 times the hardness of the substrate; the abrasion rate is 18.53 × 10–3 g/min; the porosity is 0.17% and the average adhesive strength is 8.78 Mpa, which confirms the feasibility of using aluminum ash as a spray powder to prepare a coating.

Preparation and Performance Optimization of Original Aluminum Ash Coating Based on Plasma Spraying

As an industrial solid waste, the original aluminum ash (OAA) will cause serious pollution to the air and soil. How to reuse the OAA has been a research difficulty. Thus, a method of preparing a plasma spray powder using OAA is proposed. The OAA was hydrolyzed and ball milled, and the flowability of original aluminum ash spray powder (OAASP) was evaluated by the angle of repose. The coating properties were determined via analyzing the microstructure and the phase of the coating, and the effects of plasma spray parameters on the coating properties were investigated by the orthogonal experiment to optimize spray parameters. The results show that the angle of repose of OAASP after granulation was less than 40°, which met the requirements of plasma spraying. When the spraying current was 600 A, the spraying voltage was 60 V, the main gas flow was 33 slpm, and the powder flow rate was 22 g/min, and the prepared original aluminum ash coating (OAAC) had excellent comprehensive performance. After the spraying process parameters were optimized, the microhardness of the coating was 606.54 HV, which is about twice the hardness of the substrate; the abrasion rate was 12.86 × 10−3 g/min; the porosity was 0.16%; and the adhesive strength was 16 MPa. When the amount of Al2O3 added was 50%, the hardness of the coating was increased by 17.61%.