IDENTIFIKASI KARAKTERISTIK MEKANIS BANTALAN LUNCUR MOTOR STARTER DARI SERBUK TEMBAGA ALUMUNIUM

2013 ◽  
Vol 12 (3) ◽  
Author(s):  
Syamsul Rizal ◽  
Amin Suhandi
Keyword(s):  
Mechanical Test ◽  
Life Time ◽  
Extrusion Process ◽  
Automotive Application ◽  
Powder Metallurgy Method ◽  
Powder Metal ◽  
Time Operation ◽  
Different Temperatures ◽  
Automotive Parts ◽  
Solid Form

There are many attempts to support the development of industry in Indonesia, especially on automotive sector, one of them is by replacing import components with local component products. Bushing is one of imported component that widely used on automotive application including motor strater. Bushing usually made of  copper alloy such as brass, bronz or babbit in a solid form by casting or extrusion process. In this research powder metal technology is used to process Cu-Al powder to become slide bearing of motor starter. It is expected that powder metal process not only increasing local content in automotive parts but also providing better quality by increasing life time of bushing compared to ordinary one. Cu-Al metal powder was compacted at various pressure, i.e: 250 MPa, 350 MPa and 450 MPa, and then all specimens were sintered at different temperatures : 4000C, 5000C dan 6000C for 1 hour.  After sintering specimens were air cooled to room temperature. After physical and mechanical test it can be deduced that bushing made by powder metallurgy method could increase its mechanical properties and as aresult improve its life time operation.  

A New Prediction Model on the Luminance of OLEDs Subjected to Different Reverse Biases for Alleviating Degradation in AMOLED Displays

2014 ◽  
Author(s):  
Paul C.-P. Chao ◽  
Yen-Ping Hsu ◽  
Yung-Hua Kao ◽  
Kuei-Yu Lee
Keyword(s):  
Reverse Bias ◽  
High Efficiency ◽  
Life Time ◽  
Density Currents ◽  
High Brightness ◽  
Light Emitting ◽  
Wide Viewing Angle ◽  
Time Operation ◽  
Long Time ◽  
History Of

Organic light-emitting diodes (OLEDs) have drawn much attention in areas of displays and varied illumination devices due to multiple advantages, such as high brightness, high efficiency, wide viewing angle, and simple structure. However, the long-time degradation of OLED emission is a serious drawback. This degradation was investigated by past works, which pointed out that the degradation was induced by high-density currents through OLED component under the long-time operation [1][2]. Proposed by a past work [3], different reverse biases was imposed on OLED components in display frames to alleviate the long-time degradation on OLEDs. Most recently, along with the reverse bias, new pixel circuits [4][5] for AMOLED displays are designed to alleviate OLED degradation, thus successfully extending OLED life time. However, since emission luminances in different frame times during AMOLED displaying differs significantly for displaying varied images, the OLED degradation evolves in a highly unpredictable fashion. In this study, based on valid theories, the voltage across the OLED is first used as indicator for OLED degradation. Then the relation between the level of OLED degradation, in terms of OLED’s cross voltage, and the history of imposing reverse biases are precisely modeled. With the model, the degradation of the OLED under reverse bias to extend lifetime can be successfully predicted. Based on this model, engineers can then optimize the applied reverse bias on OLEDs to maximize the OLED lifetime for varied display requirement.

Simulation on Flexible Thixo-Extrusion of Variable Cross-Section Part Based on DEFORM-3D Software

2014 ◽  
Vol 217-218 ◽  
pp. 201-207
Author(s):  
Chun Fang Wang ◽  
Kai Kun Wang ◽  
Zhe Luo
Keyword(s):  
Aluminum Alloy ◽  
Control Method ◽  
Complex Geometry ◽  
Variable Cross Section ◽  
Extrusion Process ◽  
Simulation Software ◽  
Variable Cross ◽  
Stress Strain ◽  
Different Temperatures ◽  
Deform 3D

Flexible thixo-extrusion, as an innovative near-net-shape forming method, has huge advantages in processing the components with complex geometry. However, it should keep in mind that conventional liquid casting still represents the dominant mean of aluminum alloys production. One of the obstacles the thixo-extrusion has to overcome is lack of proof that can live up to the claim that thixo-extruded components have better mechanical properties. The main aim of this paper is to simulate the flexible thixo-extrusion process of aluminum alloy A356 and investigate the control method of materials flow front. An isothermal compression test of aluminum alloy A356 is first conducted to obtain the true stress-strain curves at different temperatures and strain rates. A constitutive equation describing the relationship of stress, strain, strain rate and temperature is fitted by Origin and then imported to the DEFORM-3D simulation software. The results show that the quality of final component is enormously influenced by the radius of the arcs and the flexible thixo-extruded components has less defects compared with the conventional extruded ones.

Optimization of Process Parameters on the Mechanical Properties of Semi-Solid Extruded AA2017 Alloy Rods

2019 ◽  
Vol 6 (2) ◽  
pp. 1-14
Author(s):  
Shashikanth Ch ◽  
G Venkateswarlu ◽  
Davidson M J
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Process Parameters ◽  
Extrusion Process ◽  
Percentage Reduction ◽  
Optimization Of Process Parameters ◽  
Different Temperatures ◽  
Semi Solid ◽  
Reduction In Area ◽  
Liquidus Temperatures

The extrusion of copper-based aluminium alloys is difficult in the cold state. Extruding these alloys between the solidus and liquidus temperatures offer preferred properties on these alloys. In the present work, AA2017, a copper-based aluminium alloy has been extruded in the semi-solid state. The mechanical and metallurgical properties of the alloy vary at different temperatures between the solidus and liquidus temperatures. The aim of the present work is to optimize the process parameters, namely, temperature of billet, strain rate, approach angle and percentage reduction in area on the semi-solid extrusion of AA2017 alloy. Experiments were designed according to Taguchi experimental design and L9 orthogonal array was used to conduct the experiments. Analysis of variance (ANOVA) method was used to find the significance of every process parameter on the thixo-extrusion process responses. The results indicate that percentage reduction area is the most important factor influencing the mechanical properties of thixo-extrusion specimen followed by temperature and strain rate.

Maintainability Evaluation Based on the Product Disassembly Analysis

2009 ◽  
Author(s):  
Nan Wu ◽  
Qingjin Peng
Keyword(s):  
Product Life Cycle ◽  
Life Time ◽  
Life Cycle Management ◽  
Maintenance Cost ◽  
Product Life ◽  
Time Operation ◽  
Materials Recycling ◽  
Maintainability Analysis ◽  
The Cost ◽  
Product Disassembly

Maintainability is an important product characteristic related to the product life-time operation and the operation cost. Maintainability increases product’s serviceability and decreases product’s maintenance cost. Product disassembability is one of the key factors of product maintainability. A disassembly is normally required for product repairing, product remanufacturing, components reusing, and materials recycling in the product life-cycle management. A better disassembly plan will improve efficiency of these processes for product maintainability. This paper introduces the product maintainability analysis based on the disassembly sequence evaluation. An AND/OR graph based disassembly analysis and the cost-based evaluation are introduced for the evaluation of product maintainability. The proposed data structure and methods are discussed. The system developed is demonstrated using a case study.

scholarly journals Improved properties of Al–Si3N4 nanocomposites fabricated through a microwave sintering and hot extrusion process

RSC Advances ◽  
2017 ◽  
Vol 7 (55) ◽  
pp. 34401-34410 ◽  
Author(s):  
Penchal Reddy Matli ◽  
Fareeha Ubaid ◽  
Rana Abdul Shakoor ◽  
Gururaj Parande ◽  
Vyasaraj Manakari ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Microwave Sintering ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Powder Metallurgy Method

In this study, nano-sized Si3N4 (0, 0.5, 1.0 and 1.5 vol%)/Al composites were fabricated using a powder metallurgy method involving microwave sintering technique followed by hot extrusion.

Mechanical Properties and Process of ZnO Deposited Various Substrates

2005 ◽  
Vol 297-300 ◽  
pp. 533-538
Author(s):  
Hun Chae Jung ◽  
Han Ki Yoon ◽  
Yun Sik Yu
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Substrate Temperature ◽  
Mechanical Test ◽  
X Ray Diffraction ◽  
Electroluminescence Device ◽  
Type Semiconductor ◽  
Different Temperatures ◽  
Optimized Conditions ◽  
Substrate Hardness

ZnO is an n-type semiconductor having a hexagonal wurzite structure. ZnO exhibits good piezoelectric, photoelectric and optical properties and might be a good candidate for an electroluminescence device like an UV laser diode. But the important problems, such as substrate kinds and substrate temperature are raised its head, so they need to optimize deposit condition. Because these devices are very small and films are very thin, those are often prepared in limited quantities and shapes unsuitable for the extensive mechanical test. In this present work, ZnO thin films are prepared on the glass, GaAs (100), Si (111) and Si (100) substrates at different temperatures by the pulsed laser deposition (PLD) method. ZnO was evaluated in term of crystalline through X-ray diffraction (XRD), mechanical properties such as hardness, elastic modulus through nano-indenter. XRD measurements indicate that the substrate temperature of 200-500, 200-500, 300-500, and 300-500oC was the optimized conditions of crystalline for the glass, GaAs (100), Si (111), and Si (100) substrates, respectively. In spite of the films deposited on the different substrates, the films always show (002) orientation at the optimized conditions. Mechanical properties such as hardness and elastic modulus are influenced substrate crystallization. In case of Si (111) substrate, hardness and elastic modulus are about 10, 150GPa, respectively.

scholarly journals Thermodynamics and kinetics of thermal deactivation of catalase Aspergillus niger

2020 ◽  
Vol 22 (2) ◽  
pp. 67-72
Author(s):  
Justyna Miłek
Keyword(s):  
Aspergillus Niger ◽  
Life Time ◽  
Economic Feasibility ◽  
Thermal Deactivation ◽  
Order Model ◽  
First Order ◽  
Thermodynamics And Kinetics ◽  
Different Temperatures ◽  
Kinetics Of ◽  
Thermal Stability Of

AbstractThe thermal stability of enzyme-based biosensors is crucial in economic feasibility. In this study, thermal deactivation profiles of catalase Aspergillus niger were obtained at different temperatures in the range of 35°C to 70°C. It has been shown that the thermal deactivation of catalase Aspergillus niger follows the first-order model. The half-life time t1/2 of catalase Aspergillus niger at pH 7.0 and the temperature of 35°C and 70°C were 197 h and 1.3 h respectively. Additionally, t1/2 of catalase Aspergillus niger at the temperature of 5°C was calculated 58 months. Thermodynamic parameters the change in enthalpy ΔH*, the change in entropy ΔS* and the change Gibbs free energy ΔG* for the deactivation of catalase at different temperatures in the range of 35°C to 70°C were estimated. Catalase Aspergillus niger is predisposed to be used in biosensors by thermodynamics parameters obtained.

scholarly journals Butyl Rubber-Based Composite: Thermal Degradation and Prediction of Service Life Time 

2019 ◽  
Author(s):  
Phuong Nguyen-Tri ◽  
Ennouri Triki ◽  
Tuan Anh Nguyen
Keyword(s):  
Polymer Network ◽  
Life Time ◽  
Crosslinking Density ◽  
Butyl Rubber ◽  
Metalworking Fluids ◽  
Effect Of Temperature ◽  
Service Lifetime ◽  
Metalworking Fluid ◽  
Rubber Composite ◽  
Different Temperatures

Butyl rubber-based composite (BRC) is one of the most popular materials for the fabrication of protective glove against chemical and mechanical risks. However, in many working places such as metal manufacturing or automotive mechanical services, its mechanical hazards usually appear together with metalworking fluids (MWFs). The presence of these contaminants, particularly at high temperature, could modify its properties due to the scission, the plasticization, the crosslinking of polymer network and thus led to severe modification of mechanical and physicochemical properties of material. This work aims to determine the effect of temperature and a metalworking fluid on mechanical behavior of butyl rubber composite dealing with crosslinking density, cohesion forces and elastic constant of BRC on the based on Mooney-Rivlin’s theory. The effect of temperature with and without MWFs on thermo dynamical properties and morphology of butyl membranes is also investigated. The prediction of service lifetime is then evaluated from extrapolation of Arrhenius plot at different temperatures.

Performance and Phase Behavior of Quartz-Aluminum Matrix Composites

2014 ◽  
Vol 633 ◽  
pp. 117-120
Author(s):  
Jing Liang ◽  
Zhao Hui Huang ◽  
Kai Chen ◽  
Xiao Chao Li ◽  
Ming Hao Fang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Melting Point ◽  
Phase Behavior ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Powder Metallurgy Method ◽  
Matrix Composites ◽  
Different Temperatures ◽  
Metal Aluminum ◽  
Properties Of Composites

The performance and phase behavior of Quartz - Aluminum Matrix Composites at different temperatures were studied. Quartz aluminum matrix composites were prepared by powder metallurgy method. At the temperature that was less than 660.4°C(the melting point of aluminum), a portion of quartz was happened decomposition and revivification to silicon, most aluminum still existed in the form of metal aluminum. All quartz were happened at the temperature that was higher than 660.4°C. When the temperature is 700°C, the compressive strength of S5(added 40% quartz) is up to 46.02MP. The higher the value of compressive strength was, the less the amount of quartz were happened decomposition. At the temperature more than the melting point of aluminum, Quartz was revivification to silicon, aluminum is oxidized to Al2O3. When the amount of silica exceeded 10%, the mechanical properties of composites declined consequently.

Ballistic performance of powder metal Al5Cu-B4C composite as monolithic and laminated armor

2021 ◽  
Vol 63 (6) ◽  
pp. 512-518
Author(s):  
Mehmet Ayvaz ◽  
Hakan Cetinel
Keyword(s):  
Laminated Composite ◽  
Liquid Phase Sintering ◽  
Powder Metallurgy Method ◽  
Metal Composite ◽  
Ceramic Plate ◽  
Pressing Pressure ◽  
Powder Metal ◽  
Ballistic Performance ◽  
Composite Armor ◽  
Ballistic Tests

Abstract In this study, ballistic performances of x wt.-% B4C (x = 5, 10, and 20) reinforced Al5Cu matrix composite samples were investigated as a monolithic and laminated composite armor component. Composite armor plates were produced by the powder metallurgy method. The prepared powders were pressed under 400 MPa pressing pressure. Green compacts were pre-sintered at 400 °C for 30 minutes in order to blow the lubricant. Subsequently, liquid phase sintering was performed at 610 °C for 210 minutes. In ballistic tests, 7.62 mm caliber armor-piercing bullets were used as the ballistic threat. In the ballistic tests of monolithic armors, only 10 mm thick powder metal composite plates were tested. In the ballistic tests of laminated composite armors, these powdered metal plates were layered with 10 mm thick alumina ceramic plate front layers and 10 mm thick AA5083 plates. Although all of the monolithic powder metal composite armors were penetrated, they showed multi-hit capability. All of the laminated composite armors provided full ballistic protection. It was determined that with the increase in B4C reinforcement rate, the ballistic resistance also increased due to the improvement in strength, hardness, and abrasive feature.

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