The Effects of Heat Straightening Temperature on the Microstructure and Properties of 7N01 Aluminum Alloy

Abstract

The 7N01 aluminum alloys are always used in vehicles, but heat treatment can deteriorate mechanical properties and corrosion resistance, which limits its utilization. In this paper, the influences of the temperature of heat straightening on the corrosion behavior and mechanical properties of 7N01 aluminum alloy are investigated. Most of the initial Guinier Preston (GP) zones dissolve into the matrix during heat treatment process, while the grain boundary precipitates have no obvious change. The precipitates of the samples after heat treatment mainly consist of high density GP zones due to the natural aging effect, which result in the recovery of micro-hardness. Although heat treatment decreases the mechanical properties of 7N01 aluminum alloy, there is no obvious difference in mechanical properties of the specimens after different heat treatment conditions. The corrosion resistance of heat treatment samples decreases significantly compared with the base metal, which is attributed to enhancing the difference between the potential of the alloy matrix and the grain boundary.

Effect of Non-Isothermal Aging on the Mechanical Properties and Corrosion Resistance of 2A12 Aluminum Alloy

“…The annealed 2A12 aluminum alloy contained few grain boundary precipitates, and no continuous corrosion channels were observed. Therefore, it displayed the best intergranular corrosion resistance among the three different heating conditions [33]. The appearance of pitting (a black area) was associated with the formation of the AlCuFeMnSi phase [34].…”

Liquation Cracking Susceptibility and Mechanical Properties of 7075 Aluminum Alloy GTAW Joints

“…Aluminum alloy 7075 (AA7075) is a kind of high-specific-strength light metal. AA7075 possesses high strength under a peak aged state due to its high mass fraction of the Cu-Mg-Zn alloying element [ 8 ]. However, the metallurgical characteristics of AA7075 lead to its high susceptibility to solidification cracking and liquation cracking [ 9 , 10 ].…”

Mechanism of Precipitate Microstructure Affecting Fatigue Behavior of 7020 Aluminum Alloy

“…Underframe structural materials of high-speed train have been used in high-load, frequent acceleration and deceleration and other alternating stress environments for a long time, which require good fatigue performance to ensure the service life of the train. Precipitate characteristics in Al-Zn-Mg alloys are not only the main factors that determine the strength and corrosion performance [ 3 , 4 , 5 ], but also strongly affect the fatigue performance [ 6 , 7 ]. Therefore, it is necessary to investigate the precipitate characteristics and microscopic mechanism of 7020 aluminum alloy with optimal fatigue performance.…”