Acceleration mechanism of abrasive particle in ultrasonic polishing under synergistic physical vibration and cavitation: Numerical study.

Ultrasonic technology is widely applied in the engineering ceramic polishing processes without the limitation of material properties and ideally integrated into computer numerical control system. Ultrasonic-induced cavitation and mechanical vibration effect could accelerate the motion of solid abrasives. The individual behaviors of microjet/shockwave of ultrasonic cavitation in gases and liquids, and micro-abrasives with simple harmonic vibrations in solids and liquids has been extensively studied.

Multi-Objective Optimization in Ultrasonic Polishing of Silicon Carbide via Taguchi Method and Grey Relational Analysis.

As high-level equipment and advanced technologies continue toward sophistication, ultrasonic technology is extensively used in the polishing process of difficult-to-process materials to achieve efficiently smooth surfaces with nanometer roughness. The polishing of silicon carbide, an indispensable difficult-to-machine optical material, is extremely challenging due to its high hardness and good wear resistance. To overcome the current silicon carbide (SiC) ultrasonic polishing (UP) process deficiencies and strengthen the competitiveness of the UP industry, the multi-objective optimization based on the Taguchi-GRA method for the UP process with SiC ceramic to obtain the optimal process parameter combination is a vital and urgently demanded task.

Effects of Forging and Heat Treatment on Martensite Lath, Recrystallization and Mechanical Properties Evolution of 18Ni(250) Maraging Steel.

The manufacturing process of maraging steel parts include forging, heat treatment and other technological links, and the strengthening mechanism at different stages is different, which has an important impact on the process design of forgings. To investigate the strengthening behavior of maraging steel, forging experiments with different deformation amounts and heat treatment conditions were carried out, and the microstructural and mechanical properties evolution of 18Ni(250) steel was analyzed. The experimental results show that the size of the martensite lath is affected by multiple factors such as the influence of grain size, recrystallization and martensite substructure fraction.

Research on the Secondary Forgeability of High Volume Fraction Whisker Reinforced Aluminum Matrix Composites of Original Squeeze Casting.

The poor formability of high volume fraction whisker reinforced aluminum matrix composites of original squeeze casting is an important factor restricting its further development and application. Currently, there are no reports on the secondary forgeability of aluminum matrix composites of original squeeze casting, although some papers on its first forgeability are published. The secondary forgeability is very important for most metals.

Field study on NO emission from subsurface wastewater infiltration system under variable loading rates and drying-wetting cycles.

In this field study, the impacts of influent loadings and drying-wetting cycles on NO emission in a subsurface wastewater infiltration (SWI) system were investigated. NO emitted under different operation conditions were quantified using static chamber and gas chromatograph techniques. NO conversion rate decreased from 6.

Surface characteristics and potential ecological risk evaluation of heavy metals in the bio-char produced by co-pyrolysis from municipal sewage sludge and hazelnut shell with zinc chloride.

Municipal sewage sludge (MSS) and hazelnut shell were used for co-pyrolysis by chemical activation with ZnCl. The surface characteristics and potential ecological risk evaluation of heavy metals in the bio-char produced by co-pyrolysis were analyzed by surface analyzer and BCR sequential extraction. When raw materials with ZnCl (3mol/L) were co-pyrolyzed at 500°C for 90min, specific surface area of the bio-char is 598.

Co-pyrolysis characteristics of municipal sewage sludge and hazelnut shell by TG-DTG-MS and residue analysis.

Co-pyrolysis characteristics of municipal sewage sludge and hazelnut shell blend have been studied in this work. The behavior of co-pyrolysis was researched by a method of multi-heating rates and different blend ratios to analyze thermal decomposition stages. The experimental data of the blended samples in TG-DTG plots were compared with calculated data to investigate the interactions during co-pyrolysis.