Dissimilar Welding and Joining of Magnesium Alloys: Principles and Application

Abstract

The growing concerns regarding fuel consumption within the aerospace and transportation industries make the development of fuel-efficient systems a significant engineering challenge. Currently, materials are selected because of their abilities to satisfy engineering demands for good thermal conductivity, strength-toweight ratio, and tensile strength. These properties make magnesium an excellent option for various industrial or biomedical applications, given that is the lightest structural metal available. The utilization of magnesium alloys, however, requires suitable welding and joining processes that minimizes microstructural changes while maintaining good joint/bond strength. Currently, magnesium are joined using; mechanical fastening, adhesive bonding, brazing, fusion welding processes or diffusion bonding process. Fusion welding is the conventional process used for joining similar metals. However, the application of any welding technique to join dissimilar metals presents additional difficulties, the principal one being; the reaction of the two metals at the joint interface can create intermetallic com pounds that may have unfavorable properties and metallurgical disruptions which deteriorates the joint performance. This chapter investigates the welding and joining technologies that are currently used to join magnesium alloys with emphasis on the development of multi-material structures for applications in the biomedi cal industries. Multi-material structures often provide the most efficient design solution to engineering challenges.

Current Trends in Dissimilar Diffusion Bonding of Titanium Alloys to Stainless Steels, Aluminium and Magnesium

“…These techniques include laser welding (LW) [18], resistance spot welding (RSW) [19], friction stir welding (FSW) [20], and friction stir spot welding (FSSW) [21]. Among the available techniques, diffusion bonding [22] has the potential of joining Ti alloys to materials such as aluminium [23], stainless steel [24,25], and magnesium [16,26]. The primary disadvantage of these methods of welding is that the high temperature used in the welding process often leads to the formation of various undesirable intermetallic compounds at the interface [18,[27][28][29].…”

“…Additionally, Mg 17 Al 12 intermetallic compounds appear to have formed at the Mg grain boundaries. The joint formation occurs because of a metallurgical bonding leading to the precipitation of TiAl 3 and Ti 2 Mg 3 Al 18 [23].…”

The Influence of MSR-B Mg Alloy Surface Preparation on Bonding Properties

“…This leads to the weight reduction of the car’s structure by up to 15%, which in turn influences the reduction of exhaust emissions and fuel economy. Additionally, Mg alloys are easy to use in repair conditions [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ].…”

Bulletin of the Polish Academy of Sciences: Technical Sciences

“…Magnesium (Mg) alloys are light-weight structural materials, which have a hexagonal closed pack structure with 1.74 g/m 3 density [2]. Aluminum (Al) alloys have facecentered cubic structure with a density of 2.84 g/m 3 . Because of having the distinct crystal structure, it is not easy to weld both Mg and Al alloys by means of conventional welding techniques [3].…”

“…Aluminum (Al) alloys have facecentered cubic structure with a density of 2.84 g/m 3 . Because of having the distinct crystal structure, it is not easy to weld both Mg and Al alloys by means of conventional welding techniques [3]. Hence, the advanced joining technique of friction stir welding (FSW) is highly preferable in achieving better mechanical properties with defect-free welding [4,5].…”