Posted at 11.22.2018
Keywords: oil sump material, oil pan function
This report will analyze the engine oil pan as you of metallic component in car application. The analysis covers the role of the component, the material for the component and the properties of the material. We covers the process of how the properties are achieved. We will also analyzing the alternative material well suited for the specific component, compare with the choice material.
Engine oil pan is a simple automotive component with a very simple function. However, it's very essential for you're the engine part to use properly. By understanding the function, the precise requirement and the material for an oil pan, it would help us to comprehend more on material selection for specific automotive applications.
For engine to just work at its best, it must be running at a specific operating temperature. This temperature can only just be maintained with the aid of engine oil that acts as a coolant. Subsequently, it requires an element to store the oil and consistently reuse it. That is the key function of the engine oil pan. Besides a storage component, oil pan will also collect a few of the residue picks by engine oil while passing through the engine. Oil pan also served as a bottom cover of engines.
In in accordance with the oil pan application, certain condition and dependence on the material should be meet. First, the material for the component must have a good corrosion resistance. It really is to ensure that the oil in the sump will not contaminated. Even though the function of the oil pan is not for cooling, however the good thermal conductivity property will give an edge for the application. Furthermore, it has to have a good ductility to avoid crack or damage due to stone impact. Low density in material will be a great advantage for the component, as it will reduce the weight. Most importantly, the most crucial requirements for the component are the ability to sustain the operating temperature of the engine. However, the engine operating temperature is known as low for many kind of metallic material to withstand.
In this paper, we will analyze the properties of cast aluminum alloy as a material for the oil pan. Aluminum alloy (2. 7 g/cmЇЖ) is characterized as a nonferrous alloy, which relatively low density material compare to steel (7. 9 g/cmЇЖ) (Callister 2007). Beside lower in density, it is also comparatively high thermal conductivity and inherent corrosive resistance in a few common environment. Furthermore, the ductility of Aluminum alloys is retained at low temperature due to Aluminum has a FCC crystal structure (fig. 1-1).
Face Centered Cubic Crystal Structure. In hard sphere unit (a), a reduced sphere unit (b) and in aggregate of many atoms.
An important characteristic of the material is the precise strength, which is determined by the tensile strength to specific gravity ratio (Callister, 2007). Despite the fact that aluminum alloy have a tensile strength relatively compare to the higher density material (such as steel), over a weight basis it will able sustain a larger load (Callister, 2007).
In particular to the casting alloys use for productions of oil pan in automotive industry, the die casting process is used. Generally the AlSiMg alloys is use for the production of the oil pans.
Table 1. 1 Composition, Mechanical properties and common application for cast-heat treatable Aluminum alloys
Silicon in the range of 5 to 12% by weight is the most important factor in aluminum alloying due to ability to increase the fluidity of the molten metal as well as strengthens the aluminum. Magnesium in the range of 0. 3 to at least one 1 % by weight is added to increase strength (Smith, 2004).
The silicon content in the component will cause the formation of acicular silicon. It'll cause the considerable reduction in the ductility of the component. Which means heat treatment is essential for the component, after molding process. It is to get the appropriate satisfactory mechanical properties regarding hardness and ductility. Heat treatment process at an appropriate temperature and then for a proper duration is completed to produce the component with a new hardness. In this case, production of oil pan used the answer heat treatment and accompanied by artificial aging process, indicate by (T6) in table 1. 1. For the oil pan, in the region of a flange is kept untreated to be able to retain higher level of hardness and low degree of ductility. Thus, the hardness will be 85 to 110 HB and the ductility of 0. 5 to 2. 5%. While on the bottom region, it is heat treated appropriately to create a hardness of 55 to 80 HB and ductility greater than 4%. Hence, the ductility is increased and the hardness is reduced.
Aforementioned, we had discussed the problem and dependence on the oil pan application. With the material analysis of Aluminum alloy, we discovered that aluminum alloy has a good corrosive resistance. Furthermore, the mechanical property of aluminum alloy nearly as good thermal conductivity would provide a better heat dissipation for the engine oil. Through solution heat therapy process the aluminum oil pan experienced a sufficient ductility to sustain stone impact from bottom. Which has a considerably good hardness the aluminum alloy oil pan would keep up with the component shape from deformation due some degree of impact.
Other material commonly used to create oil pan is low carbon steel. Oil pans made of steel are produced with a stamp forming process. Physically, as opposed to the aluminum alloy oil pan, the steel oil pan is light in weight. It is because it was produce with a thin steel sheet compare to a thicker cast aluminum alloy oil pan.
Based on properties of the material, steel oil pan has a higher ductility but less hardness compare to aluminum oil pan that has high hardness and low ductility. Advantage in having high ductility material is the capability to withstand impact without crack or damage. The comparison of these material (Table 1. 2) shows the difference in elasticity, which the modulus of elasticity determined the resistance to elastic deformation. The higher the modulus (Steel alloy) the stiffer the material will be.
However, your property the condition of the component will easily deformed. In case there is oil pan application, it could damage other component inside the pan such as oil strainer. Other benefit of the aluminum oil pan as opposed to steel oil pan is the capability to acts as a noise shield, especially on diesel engine. In term of heat dissipation, aluminum oil pan will have advantage in dissipating more head compare to steel oil pan.
Table 1. 2 Room temperature Elastic, Shear Modulus and Poisson's Ratio for Aluminum Alloy and Steel Alloy.
Aluminum offers many advantages over other materials. Some of these include:
Light weight (~2/3 the weight of steel) Machinability High strength-to-weight ratio Non-oxidizing when subjected to air
Excellent heat dissipation High electrical conductivity Could be cast by all common casting methods Heat treatable for higher strength and hardness
Willian D. Callister, Jr. (2007). Materials science and engineering : an introduction, 7th Edition. United states, John Wiley & Sons, Inc.
Martin, J W. (2006). Materials for Engineering. Cambridge, Woodhead Publishing, Limited
William F. Smith (2004). Foundation of Material Science and Engineering, Third edition. NY, McGraw-Hill.