Optimization Design of Highly Efficient Aluminum-Alloy Heat Sinks for Electronic Products - Part I

Microstructure in hot cracking mechanism of welded aluminium alloys

“…1 As aluminium alloys possess an excellent ratio of strength/mass (specific strength), small densities, satisfactory thermal and electrical conductivities, superior machinability, effective resistance to corrosion and a small rate of propagation of fatigue cracks, they are widely used in many industries, including aerospace, ground transport, building construction and electronic products. [2][3][4] Various welding techniques, such as gas tungsten arc welding, gas metal arc welding, electron beam welding, laser beam welding and friction stir welding have been used to join varied structures and components made from aluminium alloy products. [5][6][7][8][9][10] Researchers have identified hot cracking as a major deficiency in the welding of aluminium alloys, mainly because they have large thermal expansion and large shrinkage, causing an increased susceptibility to hot cracking.…”

“…Aluminium, the second most abundant metallic element on earth, became an economic competitor in engineering applications as recently as the end of the nineteenth century 1. As aluminium alloys possess an excellent ratio of strength/mass (specific strength), small densities, satisfactory thermal and electrical conductivities, superior machinability, effective resistance to corrosion and a small rate of propagation of fatigue cracks, they are widely used in many industries, including aerospace, ground transport, building construction and electronic products 2 – 4. Various welding techniques, such as gas tungsten arc welding, gas metal arc welding, electron beam welding, laser beam welding and friction stir welding have been used to join varied structures and components made from aluminium alloy products 5 – 10…”