Perilaku Impak Dan Porositas Paduan Al-Si-Mg Pada Pengecoran Sentrifugal Akibat Temperatur Pemanasan Awal Cetakan

Aluminum is widely used as raw materials in engineering because this material is often used to replace other metals with the same function. This occurs when the product must have properties such as light, good heat conductivity, and low melting point. An example of making Aluminium product is centrifugal casting process. Centrifugal casting is a method of casting metal by pouring metal into a mold that rotates with a certain speed. This study aims to determine the effect of preheating temperature of the mold of on impact strength and porosity of aluminum alloy Al-Si-Mg in centrifugal casting. The experiments were carried out with and without mold pre-heating. The temperature of preheated mold were 100 º C, 200 º C, 300 º C, 400 º C. The data obtained were analyzed statistically and theoretically. The results showed that the increasing of the preheating temperature of the mold significantly affects the value of impact strength of aluminum alloy Al-Si-Mg. The highest value of impact strength and the lowest porosity were obtained in the preheating temperature of 400 º C. This is due to reduced temperature gradient between the temperature of molten metal and the mold temperature resulting in a slower cooling rate in a homogeneous suspension

Pengaruh Fraksi Volume Terhadap Kekuatan Tarik Dan Lentur Komposit Resin Berpenguat Serbuk Kayu

On the research, composite was made from polyester with volume of filler fraction variable of 15%, 30%, 45% and the type of filler was Mahogany (Swietania mahogani). The filler measurement used was 50 mesh. Polymer matrix used was BQTN 157 unsaturated resin polyester. The tensile test of experiment specimen was based on ASTM D638 M-93. and the bending specimen was based on D790-92 Standard. The higest of tensile strength on the volume fraction of 30% that is of 2.081916 kg/mm2 . For the composite material with particle of composite material mahogany with filler volume fraction of 15% had the average flexural strength of 34.98 N/mm². On the particle with volume fraction of 30% had the highest average flexural strength of 45.6780 N/mm². The higest Modulus of Elasticity(E) and Shear Modulus (G) was owned by the composite with filler volume of 635.464 kg/mm2 dan 958.85 MP

Pengaruh Kekasaran Permukaan Terhadap Porositas Hasil Hot Dipped Galvanizing (HDG)

The process of Hot Dipped Galvanizing (HDG) is done in this study in order to cover steel AISI 1010. This study is aimed at investigating the influence of the variation of roughness level of specimen towards the layer thickness and the porosity of the hot dipped galvanizing of steel AISI 1010. The level of roughness of the specimen is obtained from grinding on grid 100, 500, 800, and 1000. This process causes difference in the roughness of the surface which is measured by using the Surface Roughness Test. The controlled variable is dipping temperature of 480oC. The time of hot dipped galvanizing is 6 minutes, while the time of grinding is 3 minutes. The test done in this study is non destructive test with spray test. The result showed that the porosity increased as the function of the roughness

Implementation of Rapid Prototyping Polylactic Acid Using 3D Printing TECHNOLOGY for Early Education Applications

One of the technologies that are developing rapidly is 3D printing. 3D printing machines can create objects easily, quickly and in detail. There are three main steps that a 3D printing machine goes through, namely design, printing and finishing. 3D printers using polylactic acid are widely used in various types of fields such as industrial machinery, spacecraft, consumer goods, electronic components, vehicles, medical industry, toy industry and others.In this research, we succeeded in making an educational game tool called Tetris with the 3D printing method using polylactic acid filaments. The process of consistently creating 3-dimensional objects from digital files by arranging many layers of thin metal in succession is called 3D printing. Using additive manufacturing technology, 3D digital designs are turned into virtual products by sequentially depositing metals. 3D printing provides reasonable feasibility to meet various parameters based on the engineering arena. By utilizing the advantages of PLA material, which has good tensile strength, good surface quality, is available in various colors and user-friendly, educational game tools are produced that have the advantage of being attractive, light, strong and easy to play. That way, making educational game tools using 3D printing made from PLA can solve the problems with previous educational game tools, which are not easy to play and less attractive to early childhood. Educational games that have been made in this study can be used as a platform for learning children at the kindergarten to elementary school levels. The way to play this educational game Tetris is by attaching shapes to the main part of Tetris and matching them with other shapes, just like playing a puzzle where each shape that is installed must match the other shape