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PENGARUH PUTARAN SPINDLE SPEED TERHADAP KEAUSAN PAHAT CARBIDE PADA PROSES PEMBUBUTAN BAJA ST37

2024-02-23T12:25:42+07:00

The machining process has an important interaction between the tool and the workpiece, in which case the workpiece experiences intersection and the tool experiences friction. This friction occurs when the chisel touches the flowing surface and touches the area where the surface of the workpiece has crossed. As a result of friction, the tool wears out. Wear and tear that occurs is caused by expansion or enlargement to a specified limit, resulting in it not being used or having no function because damage has occurred. The research variables used three chisel bits and three specimens which were used to test their wear at 450 rpm, 1200 rpm and 2200 rpm rotation using a portable LCD digital microscope. Following are the results of the chisel bit research showing the wear of carbide bits using 3 specimens, so the wear value for the first tool was 3.09 µm, the second tool was 2.26 µm, and the third tool was 11.36 µm.

ANALISIS KEKUATAN IMPACT KOMPOSIT POLYESTER BERPENGUAT SERBUK KAYU JATI DENGAN VARIASI FRAKSI VOLUME MATRIKS DAN REINFORCEMENT

2024-03-12T09:41:09+07:00

The biggest problem facing the automotive industry today is limited natural resources and environmental protection. Therefore, it is very important to conduct and carry out research and mapping of alternative materials that can reduce the use of non-renewable materials. The aim of this research is to determine the effect of variations in the volume of teak wood powder on the impact strength of composites with a polyester polymer matrix and identify fracture patterns. This research uses an experimental design combined with one-way statistical analysis of variance to test the research hypothesis. The results showed that there were significant differences in impact strength between the variations of the three specimens tested. Specimens with variations in volume fraction of 20%:80% for teak wood powder and polyester resin have the highest impact strength, while specimens with variations in volume fraction of 30%:70% for teak wood powder and polyester resin have the lowest impact strength. Apart from that, examination of the microscopic structure of the fracture patterns shows differences in fracture patterns between specimens. Specimens with variations in volume fraction of 0% (100% polyester resin) show a brittle fracture mechanism, while specimens of 10%:90%, 20%:80%, 30%:70% for teak wood powder and polyester resin show that the fracture pattern that appears is a combination of fragility and fibular fracture which is also called a fibrous fracture.

ANALISIS KUALITAS BRIKET CAMPURAN KULIT KEMIRI DAN BONGGOL JAGUNG SEBAGAI BAHAN BAKAR ALTERNATIF

2024-04-02T08:51:08+07:00

The increase in human population in the world is proportional to the increase in energy needs. Energy needs are still dominated by fossil energy. Efforts to reduce dependence on fossil energy are by using natural reserves from abundant energy sources, namely biomass. Utilization of candlenut shells and corn cob waste which are abundant in the West Nusa Tenggara (NTB) area can be used as mixed materials for making charcoal briquettes. The target of this research is to analyse the quality of a mixture of charcoal briquettes from a mixture of candlenut shells and corn cobs as an alternative future fuel. In the process of this research, variations of the mixture of candlenut shells and cobs were carried out with variable composition 1 (65% candlenut husk; 25% corn cob; 10% adhesive; variable 2 (55% candlenut husk; 35% corn cob; 10% adhesive); and variable 3 (45% candlenut husk; 45% corn cob; 10% adhesive). In this test, the calorific value, combustion rate, and emission gas test were calculated. The results showed that the mixture was 65% candlenut husk, 25% corn cob, and 10% adhesive. has the highest heating value of 5010 joules, which is according to SNI at least 5000 joules, the combustion rate is 0.91 g/m, and exhaust emissions are CO (1.18), CO2 (2.92), O2 (20.9) and HC (395 ) has met Indonesian national standards according to Minister of Environment Regulation Number 05 of 2006 concerning Emission Standards.

ALAT ELEKTROPLATING BERBASIS PENGATUR WAKTU UNTUK PELAPISAN CHROME DI LABORATORIUM PELAPISAN LOGAM

2024-01-30T17:14:34+07:00

Practicum is a fairly complex teaching and learning process, but the level of complexity is always in line with human development. It is necessary to have facilities or media that can stimulate the learning process so that it runs effectively and efficiently, including tools that support practicum activities. The steel used is usually a type of low carbon steel which is corrosive in air, water and soil. This corrosion can occur because steel throws away electrons, causing the steel to oxidize. Steel that experiences oxidation can become brittle, weak, and unable to bear the load that a steel structure should support. Therefore, corrosion can reduce the durability of low-carbon steel structures as well as pipes. However, with the coating method, low carbon steel can be protected from corrosion. Coating steel using metal can be done using various methods, including electroplating (cold dipping) using the direct current method. The working principle is almost the same as electrolysis, where the galvanized metal acts as the anode, while the base metal specimen acts as the cathode. Apart from prioritizing visual results, other factors are equally important and need to be considered, such as durability and protection from corrosion. Because in certain situations, the metal's resistance to corrosion is very important. This coating refers to surface coating, which is a process of modifying the surface of a material with the aim of obtaining properties such as corrosion resistance, high hardness, high temperature resistance and wear resistance without any significant changes to the structural properties.

ANALISA PENGARUH WIND SHIELD DAN REAR BOX TERHADAP GAYA HAMBAT UDARA PADA SEPEDA MOTOR

2024-02-04T07:15:25+07:00

One of the favorite vehicles in cities and villages is a motorbike because it is practical and economical. So most of them modify their motorbikes. Starting from adding accessories such as a wind shield and rear box. An aerodynamic vehicle body shape can have an effect on reducing fuel consumption and minimizing forces that hinder the vehicle's speed. This research aims to see the difference in air resistance between motorbikes that have been modified and those that have not been modified. The simulation used uses a numerical simulation method with CFD (Computational Flow Dynamics) software. The form of modification is the addition of a wind shield and rear box. The average speed travelled in the flow simulation is 60 km/hour. The equations used in this research are the drag coefficient, velocity, drag force and flow trajectory equations. The research results show that the Windshield and Rear Box have a very significant influence on drag force. The higher the speed given, the greater the resistance force received. The addition of accessories such as a wind shield and rear box affects the drag force on a motorbike, which is the greatest at 205.28N for a speed of 80 km/hour. The largest drag coefficient is also obtained when these two accessories are added, namely 0.0071 at a speed of 80 km/hour.