PENGARUH PENCELUPAN PANAS TERHADAP UMUR PATAH DAN LAJU KOROSI ASTM A36 DALAM ALUMINIUM 7xxx

Metode hot dipping merupakan salah satu upaya yang umum dipilih untuk melindungi material dari serangan korosi. Tujuan utama dari penelitian ini adalah untuk menganalisa pengaruh variasi waktu hot dipping dalam Aluminium 7xxx terhadap ketahanan korosi dan umur patah dari ASTM A36 dengan melakukan pengujian korosi, pengukuran reduksi berat dan analisi uji kelelahan. Hasil uji korosi menunjukkan bahwa specimen dengan waktu hot dipping 2 menit memiliki nilai laju korosi yang lebih rendah dan ditandai juga dengan reduksi berat yang lebih sedikit. Pengamatan umur patah dalam 1º level tegangan menggunakan Torsee's Torsion Repeated and Bending Fatigue Machine menunjukkan spesimen dengan waktu hot dipping 2 menit dalam Aluminium 7xxx memiliki nilai ketangguhan fatik yang lebih tinggi dibanding spesimen dengan waktu hot dipping 1 menit dalam Aluminium 7xxx dan specimen non hot dipping

Mechanical properties analysis of Al-9Zn-5Cu-4Mg cast alloy by T5 heat treatment

The Improvement of mechanical properties of Al-9Zn-5Cu-4Mg cast alloy by T5 Heat treatment 200 °C during 200 hours was studied. Al-Zn-Cu-Mg alloy can be used in wide range of aircraft industry is based on the superior characteristic of this alloy. The main objective of this study is to investigate the influence of ageing process by performing tensile and hardness tests. The results revealed thatagingprocessisaffecting to the deployment of precipitationand it is indicate the formation of second phases MgZn2 by atomic reactions that lead to the change of mechanical properties of Al-9Zn-5Cu-4Mgcastalloy.

DESIGN OF AUTOCLAVE FOR FRESH SHRIMP STERILIZATON PROCESS USING FINITE ELEMENT ANALYSIS

Chloramphenicol is one of antibiotic compound which is an additional ingredient that is forbidden to be used in food products, especially in fresh shrimp product export. To avoid the used of preservative, then required sterilization process in a physical way which is vaporization using a high-pressure supercritical carbon dioxide (CO2). One of sterilization process for supercritical carbon dioxide is using autoclave media. Autoclave is a closed heating device used to sterilize or reducing a substance or object that is disserve by using high temperature and high pressure steam. In designing and constructing autoclave, the first step to be done is to define the function and the operation capacity. The function and capacity will determine the initial dimension of autoclave as well its working pressure and temperature. In this study, the autoclave was designed with quantitative methods and modeling using software Autodesk inventor 2016 based on finite element method. The given load is in the form of supercritical carbon dioxide pressure of 73.83bar and temperature of 31.30C. Based on the result of design, quantitative methods gives the safe result and optimized thickness needed autoclave usage

MATERIAL SELECTION AND MECHANICAL PROPERTIES IN LEAF SPRING APPLICATION: A REVIEW

In the industrial world, leaf springs are an important component of vehicles. Therefore, material selection is very influential in producing good mechanical properties that can affect leaf spring performance. In this review article, the author aims to review and compile articles on relevant previous studies to compare the best alternative materials other than steel that meet the criteria for the application of leaf springs. The review method used in this article is to search for articles that are relevant to the keyword material, leaf springs, and mechanical properties. After that, the author will collect articles and choose articles that have the criteria to be reviewed. Then the articles that meet the criteria will be reviewed by extracting the data to the review table. As a result, 24 articles will be reviewed. Then the author will extract data on each article, namely material, tensile strength, and flexure. Flexural and tensile strength are used as quality criteria for each material. The conclusion of the review article obtained is that carbon/epoxy has the potential as an alternative steel material because carbon/epoxy has the highest tensile strength with a value of 1841MPa, and flexural strength with a value of 1646.7MPa is close to steel as shown in the review table. However, further research is needed, such as proper design and more efficient manufacturing methods to produce innovative leaf spring components with high quality and acceptable quality in the industry

KAJIAN EKSPERIMENTAL PENGARUH VARIASI UKURAN CETAKAN LOGAM TERHADAP PERUBAHAN STRUKTUR MIKRO DAN SIFAT MEKANIK PRODUK COR ALUMINIUM

Abstrak Struktur mikro dan sifat mekanik pada suatu produk cor sangat tergantung dari ukuran cetakan produk cor tersebut. Pada penelitian ini menggunakan tiga jenis ukuran cetakan logam yaitu L-bow 1†(Als1), L-bow 1 ½“ (Als2), dan L-bow 2†(Als3). Logam yang dicor adalah Aluminium skrap sedangkan tungku pengecoran yang digunakan adalah tungku krus dengan menggunakan bahan bakar batubara. Pengujian yang dilakukan dengan uji kekerasan, uji struktur mikro dan uji komposisi kimia. Hasil dari pengujian kekerasan yang telah dilakukan didapatkan hasil bahwa produk cor dengan ukuran terkecil yaitu Als1 memiliki nilai kekerasan tertinggi yaitu rata-rata 76,82 kgf/mm², sedangkan Als2 memiliki nilai kekerasan rata-rata 73,38 kgf/mm²,dan Als3 memiliki nilai kekerasan rata-rata 72,57 kgf/mm². Jika dilihat dari proses pengujian, didapatkan hasil bahwa semakin kecil ukuran cetakan produk cor, maka nilai kekerasannya akan semakin tinggi. Demikian juga dengan pertumbuhan butir yang terbentuk, semakin kecil ukuran suatu produk cor, maka pertumbuhan butir yang terjadi pun akan semakin kecil.   Kata kunci : struktur mikro, ukuran cetakan, nilai kekerasan. Abstract Microstructure and mechanical properties in a cast product depends on the size of the mold cast product. In this study, using three kinds of metal mold size is L-bow 1 "(Als1), L-bow 1 ½" (Als2), and L-bow 2 "(Als3). Casted metal is scrap aluminum casting furnace while the furnace crucible used is by using coal fuel. Tests were conducted with hardness test, test microstructure and chemical composition test. Results of hardness testing has been done showed that the cast product with the smallest size that is Als1 has the highest hardness value is an average of 76.82 kgf / mm ², while Als2 has an average hardness value of 73.38 kgf / mm ², and has Als3 hardness value of the average 72.57 kgf / mm ².If viewed from the testing process, showed that the smaller the size of the mold cast product, the hardness value will be higher. Similarly, the grain growth is formed, the smaller the size of a cast product, the grain growth that occurs would be even smaller. Keywords: microstructure, print size, hardness value

Mechanical properties analysis of Al-9Zn-5Cu-4Mg cast alloy by T5 heat treatment

The Improvement of mechanical properties of Al-9Zn-5Cu-4Mg cast alloy by T5 Heat treatment 200 °C during 200 hours was studied. Al-Zn-Cu-Mg alloy can be used in wide range of aircraft industry is based on the superior characteristic of this alloy. The main objective of this study is to investigate the influence of ageing process by performing tensile and hardness tests. The results revealed thatagingprocessisaffecting to the deployment of precipitationand it is indicate the formation of second phases MgZn2 by atomic reactions that lead to the change of mechanical properties of Al-9Zn-5Cu-4Mgcastalloy.

Effect of ageing time 200 °C on microstructure behaviour of Al-Zn-Cu-Mg cast alloys

Al-Zn-Cu-Mg is heat treatable alloy that can be used in many hightech applications, such as aerospace and military. The main objective of this study is to investigate the influence of ageing process in microstrucure behaviour of Al-9Zn-5Cu-4Mg cast alloy by performing SEM analysis and its correlation with hardness tests of as-cast Al-9Zn-5Cu-4Mg alloy and heat treated Al-9Zn-5Cu-4Mg cast alloy. The results show the deployment of precipitation spread over the dendrite and also the presence of second phases Mg3Zn3Al2 , Cu2FeAl7 , CuAl2, and CuMgAl2 in as-cast Al-9Zn-5Cu-4Mg alloy. The presence of all these second phases are affecting to the toughness of aluminium alloy and the presence of MgZn2 leads the impairment of hardness value of heat-treated Al-9Zn-5Cu-5Mg cast alloy

Damage Analysis of Moldboard Plow

Moldboard plow is a tool used to cultivate the agricultural land. The material of the moldboard is a double layer where the outer layer is high carbon steel and the inside is a low carbon steel. The findings on the side edge of the moldboard plow are often damaged due to bent deformation and then broken. The study was conducted to determine the cause of the damage through simulation and testing laboratory. The simulation results show that the moldboard is overloaded by its material capability. This is shown also from the results of testing the chemical composition that this material is a low-alloy steel single layer without surface hardening. Hardness tests conducted using Rockwell C show that this steel has a tensile strength of only about 400 MPa. This is reinforced by the results of microstructural observations showing that more than 99% of the phases are ferrite

Damage Analysis of Moldboard Plow

Moldboard plow is a tool used to cultivate the agricultural land. The material of the moldboard is a double layer where the outer layer is high carbon steel and the inside is a low carbon steel. The findings on the side edge of the moldboard plow are often damaged due to bent deformation and then broken. The study was conducted to determine the cause of the damage through simulation and testing laboratory. The simulation results show that the moldboard is overloaded by its material capability. This is shown also from the results of testing the chemical composition that this material is a low-alloy steel single layer without surface hardening. Hardness tests conducted using Rockwell C show that this steel has a tensile strength of only about 400 MPa. This is reinforced by the results of microstructural observations showing that more than 99% of the phases are ferrite