Search

This study examines the density, porosity, microstructure, and hardness of aluminum raw materials from used pistons using gravity dies casting and gravity investment casting processes. Gravity die casting and gravity investment casting at a casting temperature of 750°C were employed in this research. Emission Spectrometry is used to determine the chemical composition of a substance (ASTM E-1251). Porosity was measured using macro photography and a digital microscope, with the findings of each mold temperature fluctuation compared. The Rockwell hardness tester is used to determine the hardness of a material (ASTM E-384). A metallographic microscope was used to examine the microstructure of the castings (ASTM E3-11). According to ASTM B-85 standards, this material comprises 71.05% (Al) composition, 13.65% (Si), 7.178% (Cu), 3.4508% (Fe), 1.7870% (Zn), and additional components up to 100%, and is categorized as Aluminum Al-Si (Aluminum-Silicon)A413.0. The density of the test object was calculated using gravity die casting at 2.6972 gr/cm3 and gravity investment casting at 2.6764 gr/cm3. The quantity of porosity impacts the density value, according to the results of porosity observations. The phase (Al) and the phase (Zr) are observed in the microstructure results (Si). In gravity investment casting, the beta phase granules (Si) appear to be larger and fewer. The beta phase granules seem smaller and more abundant in gravity die casting. The hardness value is influenced by the size, number, and dispersion of beta granules. Hardness testing with gravity investment casting yielded a hardness value of 86.84 HVN, according to the results. [ABSTRACT FROM AUTHOR]

This study aims to determine how the effect of inoculation of manganese (FeMn) on the hardness value, the results of microstructure photos, and the results of the EDS SEM test on gray cast iron material with the addition of 3% FeMn. In this casting process using an induction smelting furnace with a temperature of 1300 – 1400 C the material used for smelting is iron (Fe), melted and then mixed with 3% FeMn after being mixed poured into metal molds and prepared sand. The results of the hardness test show that the hardness values vary in the upper, lower, and intermediate metal molds. The results of microstructure testing of metal molds, transitional molds, and sand molds at the bottom are the hardest because the graphite is neatly arranged and visible. The results of the SEM-EDS test of the Mn element in the metal mold were detected at 3.45% and in the sand mold at 0.00%, the Mn sand mold was detected on the graph but did not appear in the data table because it was covered by Fe, C, and Si elements. [ABSTRACT FROM AUTHOR]

A grinder is a tool used in manufacturing processes such as finishing workpieces and smoothing cuts or welding products, and it can also be used to sharpen metal tools such as knives and chisels with an abrasive material. In this study, the wear rate of a self-manufactured grinding stone made from aluminum slag treated with HCl as the abrasive material was compared to grinding stones from previous studies and commercial grinding stones sold on the market using the ASTM D-3702 standard wear test. The self-manufactured grinding stone was made of liquid and powder phenolic resins, cast aluminum slag, water and HCl-treated meshes 12 and 40, and fiberglass mesh fibers. The mixture is then combined with a predetermined composition. The mixture is then placed in a mold and compacted for 5 minutes with a press machine with a force of 15 tons, allowed to stand at room temperature for at least 24 hours, and sintered at 140 degrees Celsius for 1 hour. The results showed that the average wear value of the grinding stone with HCl treatment is higher than the wear value of the grinding stone with water treatment, which is 0.0664 gram/minute and 0.0129 gram/minute, respectively. The commercial grinding stone had the lowest average wear value of 0.0031 gram/minute. Surprisingly, the wear value of commercial grinding stones is lower than the wear rate of self-designed grinding stones. [ABSTRACT FROM AUTHOR]

The metal will experience a phase change during the casting process, both changes in physical and mechanical properties caused by the freezing process. Changes in these properties are influenced, among others, by the cooling medium used during the cooling process. Because the physical and mechanical properties of a metal are very important in machinery construction, in this study different cooling media were used, namely: seawater, well water, and SAE 40 oil. The purpose of this study was to determine the effect of different cooling media on seawater, water wells, and SAE 40 oil on the chemical composition of brass cast products, hardness, and microstructure of brass castings. From the hardness test, the test object with seawater media has a better hardness value than well water and SAE 40 oil. From the results of testing the chemical composition, there are 18 elements, but only 4 elements have the most influence on cast brass, namely: Cu, Zn, Fe, and Sn are the most dominant. Judging from the elements present in this material, it can be classified as brass, and zinc alloy (Cu-Zn). [ABSTRACT FROM AUTHOR]