Introduction

GENERAL: By developing technology of today, the necessity of using different materials by joining came out. The most suitable method in joining two different alloyed steel is to weld. The establishment of energy saving and natural resource saving systems is an important issue, and relevant researches, development should be accomplished without delay. Making structures lighter is one way to save energy. The study of light metals such as aluminium alloys and magnesium alloys has received much attention. Aluminium alloys are especially attractive because of superior recyclability and workability. The performance and life time of the industrial machineries and components are mainly based on the materials and manufacturing processes involved during their production. These components are made by similar or dissimilar materials depending on the application. In several applications the materials employed are location dependent in the same structure of the component to perform the required task and it is to be welded with suitable welding processes. Such joining of dissimilar materials normally is far more complex and generally more challenging than that of similar metals because of difference in the physical, thermal, electrical, mechanical and metallurgical properties of the parts to be joined. In order to take full advantage of the dissimilar metals involved, it is necessary to produce high quality joints between them (Manjubhargavi et al., 2009). Welding is one of the fast growing principal technologies used for joining materials which is almost used by all the fabricating industries. There are stringent needs of today’s fabrication industry demand the use of cost effective materials and procedures apart from quality and safety standards (Handa and Chawla, 2013).

ALUMINIUM AND ITS ALLOYS: Earth crust contains about 8% of aluminium. Aluminium has since been identified as the most common metal on earth. It is the third most abundant element produced from the earth surface. Aluminium is the backbone of the aerospace industry, and used as canning and packaging material for foodstuffs and number of other items, like making pans and utensils for cooking. Aluminium also used for various electrical applications. The properties of a particular aluminium product depend on which aluminium alloy is chosen for a particular work, because the term aluminium refers to a family of alloys. In aluminium alloys aluminium is predominant metal. There are large numbers of aluminium alloys present for various applications, in which the typical alloying elements are copper, magnesium, manganese, silicon, tin, zinc and etc. Aluminium alloys present a great potential as structural materials in the aerospace and automobile industries because of several advantages, such as low density, high specific strength high strength-to-weight ratio and excellent resistance to corrosion. Aluminium alloys are alloys in which aluminium (Al) is the predominant metal. The typical alloying elements are copper, magnesium, manganese, silicon and zinc. There are two principal classifications, namely casting alloys and wrought alloys, both of which are further subdivided into the categories heat-treatable and non-heat-treatable. About 85% of aluminium is used for wrought products, for example rolled plate, foils and extrusions. Cast aluminium alloys yield cost effective products due to the low melting point, although they generally have lower tensile strengths than wrought alloys. The most important cast aluminium alloy system is Al-Si, where the high levels of silicon (4.0% to 13%) contribute to give good casting characteristics. Aluminium alloys are widely used in engineering structures and components where light weight or corrosion resistance is required (Sahin and Misirli, 2013). Al alloys which we are using these are Al6082 and Al6063.

PROPERTIES OF ALUMINIUM AND ITS ALLOYS:(A) Light weight, high strength: Aluminium and its alloys are light in weight. The specific weight of aluminium is one third that of steel. So it is used for various applications where low weight and high strength are required. Lightweight aluminium results in low energy consumption and increased load capacity. Due to lightweight aluminium and its alloys are used in ships, aeroplanes etc.

(B) Electrical conductivity: The electrical conductivity of pure aluminium at 20 degree C is 63.8% of the International Annealed Copper Standard (IACS). And electrical conductivity of aluminium alloys as varies according to composition of alloys. Because of its low specific gravity, the mass electrical conductivity of pure aluminium is more than twice that of annealed copper.

(C) Thermal conductivity: The thermal conductivity of aluminium is twice that of copper because of its low specific gravity. The thermal conductivity of pure aluminium is 244 W/mK for the temperature range 0-100 degree C which is 61.9% of the IACS.

(D) Corrosion Resistance: Aluminium and its alloys have a higher resistance to corrosion than many other metals owing to the protection conferred by the thin film of oxide. This oxide layer is always present on the surface of aluminium in oxygen atmospheres.

(E) Melting point: The melting point of pure aluminium is 660 degree C and melting points reduce as purity of aluminium decreases. The addition of alloying elements reduces this still further down to nearby 500 degree C.

ADVANTAGES OF ALUMINIUM ALLOYS: Greater strength, Good stiffness, Less weight, Better high, temperature properties, Better damping properties, Good wear resistance and Reduced density.

APPLICATIONS OF ALUMINIUM ALLOYS: Military weapon, Aerospace and automobiles, Engine piston, Cylinder liner, Brake disc and drum,

WHY USE FRICTION WELDING: By developing technology of today, the necessity of using different materials by joining came out. The most suitable method in joining two different alloyed steel is to weld. The fact that the properties of welding zone are naturally different from the properties of different aluminium alloys in post welding process and these differences came up with some important problems.

Impressum

Verlag: BookRix GmbH & Co. KG

Tag der Veröffentlichung: 14.01.2020
ISBN: 978-3-7487-2599-2

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