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The performance of palm oil as a lubricant in a cold metal forming process was tested and evaluated by carrying out plane strain extrusion experiments and experimental analyses using a visioplasticity method. In the present research, two types of refined palm oil, refined, bleached, and deodorized (RBD) palm olein and RBD palm stearin, were tested as lubricants. The workpiece material was aluminum JIS-A1050. The experiments were carried out at room temperature (22 • C). Paraffinic mineral oils with varying degrees of viscosity were tested for comparison. The experiment used an extrusion apparatus in which the taper dies were facing together, with zero frictional constraint at the contact plane (corresponding to the plane plate tool) conducted, and results were compared with those extruded with lubricants. Extrusion load and surface roughness of the billets were measured and compared. The distribution of the material flow velocity and effective strain in the exit zone of the billets were calculated using the visioplasticity method, and these data were also compared. The results confirmed that RBD palm olein and palm stearin provide sufficient lubrication performance in the cold work metal forming process.

Environmental pollution issue has made humankind tend to choose plant based oil instead of mineral based oil especially in lubrication usage. This decision is make based on several useful characteristic of plant oil where they are rapidly biodegradable, renewable, excellent lubricants and inexpensive to produce. Even though this oil show poor stability of oxidation and unfavorable properties at low temperature, currently researchers have proven that by altering the structure of plant oil it could solve this problem. Thus, several vegetable oil has been selected which are palm oil, jatropha oil and soybean oil to be test their performance in lubrication system for stamping and hydraulic purpose. These plant oils will be tested according to ASTM D 4172 and ASTM D 2783 by using four-ball tester machine. This experiment will be focus on the performance of plant oil as a lubricant and the effects of wear on the ball bearing based on the influence of the characteristics of plant oil itself.

In this paper, nonlinear boundary value problems are analyzed by using the over-range collocation method (ORCM). By introducing some collocation points, which are located at outside of domain of the analyzed body, unsatisfactory issue of the positivity conditions of boundary points in collocation methods can be avoided. Quite accurate numerical results of the nonlinear partial differential equations have been obtained. Because the ORCM does not demand any specific type of partial differential equations, it shows promise of wide engineering applications of the ORCM.

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