Influence of grain refiner addition and heat treatment on the mechanical properties of Al-Si alloy
In the present investigation, an attempt is made to study the effect of addition of grain refinement on Al-Si alloy, when it is subjected to the combined grain refiner addition (Al-5T-1B) and subjected to mechanical vibration and heat treatment. The material is tested for hardness property and dry sliding wear properties. The results of the present investigation indicate that there is a considerable improvement in the hardness valves, microstructure and resistance for wear.
Effect of grain refinement and modification on the dry sliding wear behaviour of eutectic Al–Si alloys
Abstract The present study deals with an investigation of dry sliding wear behaviour of grain refined and or modified eutectic (Al–12Si) Al–Si alloy by using a Pin-On-Disc machine. The indigenously developed Al–1Ti–3B and Al–10Sr master alloys were used as grain refiner and modifier for the grain refinement of α -Al dendrites and modification of eutectic Si, respectively. Various parameters have been studied such as alloy composition, sliding speed, sliding distance and normal pressure. The cast alloys, master alloys and worn surfaces were characterized by SEM/EDX microanalysis. Results suggest that, the wear resistance of eutectic Al–Si alloys increases with the addition of grain refiner (Al–1Ti–3B) and or modifier (Al–10Sr). Further, the worn surface studies show that adhesive wear was observed in Al–12Si alloy in the absence of grain refiner and modifier. However, an abrasive and oxidative wear was observed when the grain refiner and modifier are added to the same alloy. Commercially available LM-6 (12.5%Si) alloy was used for comparison.
Correlation between Fluoride Release, Microhardness and Solubility of High viscosity Glass Ionomers
This study was to measure and compare the amount of fluoride, microhardness and solubility of high viscosity glass ionomer and resin-reinforced glass ionomer during 84 days. Fuji IX GP EXTRA, Fuji IX GP, Fuji II LC and FiltekTM Z350XT stored in deionized water for 84 days to measure fluoride release, microhardness and solubility. As a result of measurement of fluoride release, all the glass ionomers showed the highest amount of fluoride release on day 1 and gradually decreased. Fuji IX GP EXTRA showed the highest amount of fluoride release and cumulative release. And Fuji IX GP and Fuji II LC showed no significant difference. Microhardness measurements showed that all experimental groups decreased 1 day after exposure to water. After 84 days, microhardness showed no significant difference between Fuji IX GP EXTRA and Fuji IX GP, and Fuji II LC was the lowest. In the solubility measurement, Fuji IX GP EXTRA, Fuji IX GP, and Fuji II LC increased rapidly to 21 days. After 21 days, there was no significant difference in the three groups. As a result, short term fluoride release affects solubility and microhardness, but long term fluoride release has no correlation. Through this study, the amount of fluoride, microhardness, and solubility of various glass ionomers were evaluated, and these properties could be applied clinically.