The Effect of a Zinc Interlayer on the Microstructure and Mechanical Properties of a Magnesium Alloy (AZ31)–Aluminum Alloy (6060) Joint Produced by Liquid–Solid Compound Casting

Abstract

Bimetallic AZ31/6060 joints were produced by compound casting. The process involved pouring liquid magnesium alloy onto a solid aluminum alloy insert placed in a mold. Inserts with and without a zinc surface layer were used. For an insert with no Zn layer, the bonding zone was characterized by a nonhomogeneous microstructure. In the area adjacent to the AZ31, there was a eutectic (c and a(Mg)). In the area close to the 6060 alloy, two continuous layers of the c and b phases were detected. When a 6060 insert with a Zn layer was used, the bonding zone was mainly composed of Mg-Al-Zn phases. The joint without a Zn interlayer had low shear strength . The presence of the Zn interlayer caused a significant increase in the joint strength (39.8-46.6 MPa). The micro-indentation data suggest a less brittle fracture character of the bonding zone with a Zn layer.

Development and Optimization of Tin/Flux Mixture for Direct Tinning and Interfacial Bonding in Aluminum/Steel Bimetallic Compound Casting

“…Otherwise, for low melting point metals, the reaction time will be much lower, resulting in lower wettability. A wise approach is to introduce an additional metal or alloy between the coupled metals and control the structure of the interfacial bonded zone to prevent the formation of intermetallic phases and improve the bimetallic wettability [ 6 , 9 , 10 , 11 ]. Recently, Ramadan et al [ 9 ] have improved the shear strength of the Sn interlayer in bimetallic bearings by the addition of Cu.…”

“…Recently, Ramadan et al [ 9 ] have improved the shear strength of the Sn interlayer in bimetallic bearings by the addition of Cu. Therefore, Sn, Zn and Sn-Pb alloy are the proposed metals that can be used in the fabrication of interlayers in liquid–solid bimetallic journal and thrust bearings [ 6 , 9 , 11 ].…”

“…It has been reported [ 11 ] that Zn interlayer for bimetallic Mg/Al joints significantly increased the bonding strength. Sn and Sn-Pb alloys [ 6 , 8 , 15 ] are commonly used as interlayers for the fabrication of bimetallic materials using liquid–solid compound casting technique.…”

Fabrication of Surface Layer Enriched with Zinc on AlSi17 Aluminium Cast Alloy by Hot-Dip Galvanizing

“…The layers enriched with zinc on the surface of the aluminium alloys are fabricated to improve the properties of the joints between them and other metallic materials. The literature data include the studies on the effect of a Zn interlayer on the microstructure and properties of pure Al or Al alloy combined with other metals such as Mg [3][4][5][6][7][8] or Cu [9], fabricated by brazing [3], friction stir welding [4], diffusion bonding [5], welding [6,7], compound casting [8] or ultrasonic welding [9]. The combination of an Al alloy with other metals with the use of a Zn interlayer requires the enrichment of the Al surface with Zn prior to the joining process.…”

“…The combination of an Al alloy with other metals with the use of a Zn interlayer requires the enrichment of the Al surface with Zn prior to the joining process. The layers enriched with Zn on Al alloys can be produced by hot-dipping [3][4][5], diffusion bonding [8] electrolysis [10][11][12], or electroless deposition [10,13]. Some methods allow the application of Zn between Al alloy and other metal during joining process [6,7,9].…”