Measurement of coefficient of friction under bulk plastic deformation by using plane strain extrusion apparatus with plane plate tool and taper die

A series of experiment to measure coefficient of friction under bulk plastic deformation in plane strain extrusion was carried out by using the apparatus in which a taper die and a plane plate tool were arranged in facing each other. The plane plate tool had detection part of the normal and frictional forces acting on the tool surface so that coefficient of friction could be measured. Conditions of frictional constraint on the surface of plane plate tool were changed by applying the lubricant with high viscosity or lubricant with low viscosity. While, lubricant applied to the other contact surfaces with billet such as the surfaces of taper die and sidewall was fixed to one kind. Billet was made of Aluminum (A1050-JIS) and the extrusion apparatus was made of SKD-11-JIS. Then, the values of coefficient of friction were measured and surface conditions of a billet were investigated on the plane plate tool side. Differences of the conditions of material flow and effective strain in whole area of deformation zone of a billet, which were affected with different frictional constraint on the surface of plane plate, were also investigated by carrying out the visioplasticy analysis

The influence of Zinc-Dialkyl-Dithiophosphate (ZDDP) additives on the tribological performance of RBD palm kernel / Nurul Farhanah Azman...[et al.]

Vegetable oil based lubricant has received much attention in recent years due to its biodegradable properties, low toxicity and environmental friendly. This study used refined, bleached and deodorized (RBD) palm kernel blended with zinc-dialkyl-dithiophosphate (ZDDP) to evaluate the tribological performance as a potential alternative lubricant. The ZDDP additives were added with concentration of 0wt%, 1wt%, 3wt% and 5wt%. Commercial mineral oil SAE 40 was used for comparison purposes. The tests were performed at 1.5 m/s and 3.5 m/s of sliding speed under 9.81 applied load for 1 hour at room temperature. The results indicate that the presence of ZDDP in RBD palm kernel have improved both friction reducing and anti-wear performance. The formulation of RBD palm kernel have the potential to be used as a substitution for mineral based lubricant in near future. The authors would like to express their thanks to the Research Management Centre (RMC) of Universiti Teknologi Malaysia for the Research University Grant, GUP (12H98, 09H64), Fundamental Research Grant Scheme, FRGS (4F610), and Ministry of Education of Malaysia and Ministry of Higher Education for their support; they also thank the Faculty of Mechanical Engineering, Universiti Teknologi Malaysia for the laboratory facilities

Tribological evaluation of mineral oil and vegetable oil as a lubricant

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

The effect of lubricant viscosity in cold work forward extrusion

In cold work extrusion, lubricants play an important role in lubricating the tool and workpiece surfaces, preventing metal-to-metal contact and reducing sliding friction, so that the workpiece can be extruded smoothly without severe wear due to lubricant starvation. In this paper, the influence of lubricant viscosity in cold work forward extrusion was investigated. The lubricants were additive-free, paraffinic mineral oil, which may have low, medium or high viscosity. The workpiece material was pure aluminum A1100, extruded with extrusion ratio of 3. The analysis focused on extrusion force, workpiece surface roughness after the extrusion process and the metal flow in the deformation zone of the workpiece. Using the visioplasticity method, the sliding velocity was calculated from the metal flow. Results showed that, the higher the lubricant viscosity, the lower the extrusion force generated. However, a high-viscosity lubricant produces coarser workpiece surface conditions after the extrusion process

Experimental evaluation of refined, bleached, and deodorized palm olein and palm stearin in cold extrusion of aluminum a1050

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

Investigation of frictional constraint effect of RBD palm stearin as lubricant by plane strain extrusion

In this paper, RBD palm stearin, which is one of the refined products of palm oil, was tested as cold metal working lubricant by plane strain extrusion. Whole experiments were carried out at room temperature 20°C. Pure aluminum A1050 was used as a workpiece. In these experiments, the extrusion loads were measured and the surface conditions of workpieces were observed. The distribution of relative velocity was calculated in the deformation zone of workpiece by applying the visioplasticity method. Similar experimental and analytical investigations were carried out for a conventional lubricant, paraffinic mineral oil, and the results were compared to those of the RBD palm stearin. Present investigation confirms that lubrication effect of RBD palm stearin reducing the frictional constraint in the cold metal forming is similar to that of mineral base lubricating oil. However, the existence of RBD palm stearin in solid state at around room temperature affects the surface condition of workpiece, and coarser roughness condition is observed in cold extrusion