Optimization of Mechanical Properties of Al–Al‐Compound Castings by Adapted Heat Treatment

Abstract

Aluminum–aluminum compound castings consisting of an aluminum wrought alloy sheet and an aluminum casting alloy are produced via high pressure die casting (HPDC). In order to realize a firm bonding, the sheet material is Zn‐coated prior to casting. The task of the Zn‐coating is to replace the resistant aluminum oxide layer on the surface. In addition, a smooth metal–metal interface between the insert and the casting alloy develops by the diffusion of Zn atoms into the surrounding area of the interface. Within this paper, the subsequent heat treatment of the resultant formation is investigated to enhance the strength of the firmly bonded compound. In a first step, heat treatment for two wrought alloys AlZn5.5MgCu, AlCu4MgSi, and the casting alloy AlSi10Mg(Fe) are examined. Based on these results, suitable parameters for the heat treatment of the compounds are selected and tested. Mechanical tests demonstrate a significant enhancement for the strength of the heat treated compounds. Microprobe analysis is used to examine the diffusion and dissolution of the coated Zn at the boundary layer during the solution annealing of the firmly bonded compound.

New Materials and Processes for Transport Applications: Going Hybrid and Beyond

“…Structures of this kind have been commercialized under the designation Variostruct, a typical example being a sheet metal (typically steel) based beam like structure of convex cross section which is reinforced and stiffened by high pressure die cast aluminum ribs, with the joint between steel and Al created via the HPDC process and deriving its strength mainly from form fit and lesser contributions from force fit and metallic joints . In general, improving reproducibility and performance of the latter remains a primary research objective which has, for example, been addressed by Schwankl et al and Fang . An application‐oriented case study on steel‐aluminum compound casting has been published by Schittenhelm et al looking at a local reinforcement of a rear longitudinal carrier via a completely embedded steel structure: The resulting hybrid component offers high stiffness at reduced volume and may thus be interesting for applications with limited availability of space …”

Effect of Artificial Aging Treatment on the Mechanical Properties and Regulation of Precipitated Phase Particles of High-Pressure Die-Cast Thin-Wall AlSi10MnMg Longitudinal Carrier

“…Notably, the additional battery costs required to achieve an equivalent range are significantly higher [ 5 , 6 ]. Die-cast aluminum alloys are more prevalent in automotive manufacturing than wrought aluminum alloys, making the development of aluminum alloy die-casting technology and its associated heat treatment processes a crucial area of research [ 7 , 8 , 9 , 10 ]. High-quality AlSi10MnMg aluminum alloy castings are extensively used in manufacturing automotive structural components, such as housing towers, longitudinal carriers, and transverse bearing beams [ 11 , 12 , 13 , 14 ].…”

Bonding of cast iron-aluminum in bimetallic castings by high-pressure die casting process

“…However, due to the difference in the thermalphysical properties, metallurgical bonding is extremely di cult to achieve for compound casting of dissimilar metals. Even for similar metallic couples, owing to the formation of oxide layer on surface of the solid substrate, the wettability between solid-state and liquid-state metals is largely impaired, leading to an incompatible and poor bonding between two metal components [19,20]. There are a number of attempts to protect the surface of solid substrate metals from oxidation and to obtain an excellent metallurgical bonding between similar and also dissimilar metallic couples.…”