Performance Analysis of Friction Stir Welded Lightweight Aluminum Alloy Sheet

The present research envisaged the performance analysis of a 1-mm thick 6061-T6 aluminum alloy sheet welded by the friction stir welding technique, using optical microscopy, micro-hardness measurement, a tensile test, a friction and wear test, and a salt spray corrosion test. It was found that the grain in the welded zone obtained was refined under each parameter. When the rotating speed of the tool was 15,000 rpm and the traveling speed of the tool was 300 mm·min-1, the tensile strength of the welded zone was highest, i.e. 74.8% of the base metal. Furthermore, the hardness distribution curve of the welded zone was of the 'W' type under each parameter, but the hardness value was lower than that of the base metal. The friction coefficient of the welded zone was lower than that of the base metal under each parameter, and the wear form was found to be mainly adhesive wear accompanied by abrasive wear. The welded zone and the base metal were subjected to salt spray corrosion after 12 hours under each parameter, which had a negative effect on the quality. However, after 12 hours of subsequent corrosion, the quality of each sample and the base material was not obvious

Application of Fibonacci Sequence and Lucas Sequence on the Design of the Toilet Siphon Pipe Shape

The purpose of this study was to explore the method for designing the toilet siphon pipe shape to improve flushing performance. The Fibonacci sequence and the Lucas sequence were used to design the structural parameters of the siphon pipe. The flushing processes of the toilet were simulated using the computational fluid dynamics (CFD) method to analyze the flushing performance under different siphon pipe shapes. Experimental studies were conducted to verify the reliability of the simulation results. The results indicated that when the Lucas numbers and the Fibonacci numbers were utilized to regulate the curvature of the siphon pipe in the Xi direction and the Yj direction respectively, the flushing performance of the toilet was optimal. In order to obtain better flushing performance, the curvature of the siphon pipe should be smooth and have obvious transitions at the connections of different sections. When the overall size of the siphon pipe is kept constant, a short siphon pipe length is helpful for the improvement of toilet flushing performance

Study on the Influence of Toilet Siphon Pipe Shape on Flushing Performance

The goal of this work was to explore the influence of toilet siphon pipe shape on flushing performance. The flushing processes of a toilet under different shape parameters were simulated by using computational fluid dynamics (CFD) with a volume of fluid (VOF) multiphase model. The effects of siphon pipe shape on flushing performance were analyzed in detail. The interpretation of the simulation results was experimentally validated. The results reveal that a toilet may obtain good flushing performance under one single shape parameter when the climbing angle, the arc width, the arc height, the pipe diameter, the climbing width, and the climbing height are about 48°, 45 mm, 210 mm, 50 mm, 90 mm and 30 mm, respectively. With the increase of the siphon pipe diameter, the toilet flushing performance peaks in the range between 50 and 53 mm rather than continuing to improve. In order to reasonably evaluate the flushing effect of the toilet, all flow parameters on a characteristic cross section of the siphon pipe, including the average velocity, the average pressure and the average mass flow rate, should be comprehensively considered instead of one single parameter. The findings of this study provide a reference for the pipe shape design of toilets

Influence of the Process Parameters on the Microhardness and the Wear Resistance of Friction Stir Processed H65 Copper Alloy

Friction stir processing (FSP) was used to modify a larger-size surface of H65 copper alloy. The influence of the traverse speed and the rotation speed on the microstructure, the microhardness and the wear resistance of the modified surface were analyzed. The wear mechanism of the modified H65 copper alloy was revealed. The results indicate that the grain size was greatly refined after FSP compared with the parent metal and that the grain size increased with the increment of the rotation speed. The average microhardness of the modified surface was higher than that of the parent metal. The average microhardness had a highest value of 174.13 HV when the traverse speed was 200 mm/min and the rotation speed was 200 rpm, i.e., 21% higher than that of the parent metal. The average microhardness decreased with the increase of the rotation speed. When the traverse speed was 200 mm/min and the rotation speed was 600 rpm, the average friction coefficient of the modified surface was the smallest (0.3213), which was lower than that of the parent metal (0.3810). The wear mechanism of the H65 copper alloy modified by FSP was mainly adhesive wear accompanied by local abrasive wear

Influence of the Process Parameters on the Microhardness and the Wear Resistance of Friction Stir Processed H65 Copper Alloy

Friction stir processing (FSP) was used to modify a larger-size surface of H65 copper alloy. The influence of the traverse speed and the rotation speed on the microstructure, the microhardness and the wear resistance of the modified surface were analyzed. The wear mechanism of the modified H65 copper alloy was revealed. The results indicate that the grain size was greatly refined after FSP compared with the parent metal and that the grain size increased with the increment of the rotation speed. The average microhardness of the modified surface was higher than that of the parent metal. The average microhardness had a highest value of 174.13 HV when the traverse speed was 200 mm/min and the rotation speed was 200 rpm, i.e., 21% higher than that of the parent metal. The average microhardness decreased with the increase of the rotation speed. When the traverse speed was 200 mm/min and the rotation speed was 600 rpm, the average friction coefficient of the modified surface was the smallest (0.3213), which was lower than that of the parent metal (0.3810). The wear mechanism of the H65 copper alloy modified by FSP was mainly adhesive wear accompanied by local abrasive wear