Effect of Compositional and Processing Variations in New 5182-Type AlMgMn Alloys on Mechanical Properties and Deformation Surface Quality

Abstract

Laboratory-scale sheets of 5182-type AlMgMn alloys with varying Mg and Mn contents and additions of different amounts of Zn, Cu, Zr and Er were studied. The sheets were produced using two different cold-rolling degrees and two soft-annealing treatment procedures: air-circulated furnace annealing at 370 °C with subsequent furnace cooling, and salt-bath annealing with subsequent water quenching. Mechanical properties and deformation surface quality were studied via tensile tests with simultaneous visual surface characterization. The influence of the chemical composition and the processing route on grain size, mechanical properties, and surface quality is discussed in the study. A reduction in the Mg content improves the surface quality after plastic deformation, but at the expense of the mechanical properties. The results suggest the presence of an optimum Mn content in terms of optical appearance and mechanical properties. Adding Zr largely inhibits recrystallization, which is reflected in a textured microstructure. Adding Er affects neither the surface quality nor the mechanical properties. Specific combinations of Zn or Cu addition, cold-rolling degree, and heat treatment generate significant improvements in the mechanical and optical properties. In general, annealing at high temperature with subsequent quenching leads to enhanced surface quality and mechanical properties, and adding Zn enables further noteworthy improvements.

Room Temperature Recovery of Cryogenically Deformed Aluminium Alloys

“…Firstly, alloy EN AW 6016 T4 in natural aged condition contains a very low content of magnesium atoms in solid solution and also displays the respective behaviour. Although dissolution of Mg-Si clusters after extensive dislocation cutting may increase Mg in solid solution, the maximum possible amount for achieving Lüders yielding does not match the observations of several authors [5,6,58,59]. Secondly, these "stress plateaus" occur and also vanish in alloy EN AW 5182 O after longer recovery times and exhibit mostly negative slopes.…”

“…In addition, low surface quality prevents the usage of Al-Mg based systems for exterior application or visible parts [4]. Interaction between the magnesium solute atoms and dislocations causes Lüders yielding or PLC effects (also known as dynamic strain aging) [5,6]. Both generate an uneven surface, visible in flame-shaped elevations (stretcher strain markings) or bands.…”

Evolution of Microstructure and Texture in Laboratory- and Industrial-Scaled Production of Automotive Al-Sheets

“…The chemical composition is given in Table 1. Sample production is based on a conventional production process of 5xxx and 6xxx alloys, as shown schematically in Figure 2 [45,46]. The usual industrial processing parameters [4,15] were used for the industrially scaled path, the aluminum sheets produced by Austria Metall AG (AMAG) rolling GmbH.…”

“…In addition to the information given in Figure 2, cast and homogenized microstructures were prepared by means of Casting: The ingot material for both alloys was provided by AMAG rolling GmbH company, Ranshofen, Austria. Initially, the ingot material was remelted in a resistance-heated furnace (Nabertherm K20/13/S, Lilienthal, Germany), degassed using an impeller with Ar gas, and finally casted into laboratory-scaled molds [45]. After milling to block sizes of 80 × 80 × 40 mm 3 , samples of EN AW-6016 were homogenized in an air-circulated furnace for 10 h at 565 • C with subsequent air cooling, while EN AW-5182 remained untreated.…”

Annealing Effect on the Microstructure and Mechanical Properties of AA 5182 Aluminum Alloy

“…The alloy of the 5xxx series possessesMg as its main element and, among its variations, the alloy AA5182 is highlighted here due to its use in can end stock (CES). The strength of the non-heat treatable AA 5xxx series aluminum alloy is due to a combination of solid solution hardening with Mg and dispersion hardening by Mn and other alloying elements in the formation of dispersoids 4,5 . Another type of increase in mechanical strength of this aluminum series is due to plastic deformation which affectsthe grain size 6 , displacement density 7 and texture developed during the deformation process 8 .…”