Effect of Shot Peen Forming on Corrosion-Resistant of 2024 Aluminum Alloy in Salt Spray Environment

Abstract

The effect of shot peen forming on the corrosion-resistant of 2024 aluminum alloy in a salt spray environment was studied with an electrochemical workstation. The surface morphology and cross sectional morphology of the original and shot peen-formed sample were studied by a scanning electron microscope. After shot peen forming, the salt spray corrosion resistance of 2024 aluminum alloy was worsened (the corrosion rates of the original alloy and the shot peen-formed alloy were 0.10467 mg/(cm2×h) and 0.27333 mg/(cm2×h), respectively, when the salt spray corrosion time was 5 h). The radius of capacitive reactance arc of the sample subjected to shot peen forming was smaller than that of the original sample. When the salt spray corrosion time was 5 h, the doping density (NA) of the original alloy was 2.5128 ´ 10−13 /cm3. After shot peen forming, the NA of the alloy increased to 15 ´ 10−13 /cm3. For the shot peen-formed sample, pitting corrosion first occurred in the crater lap zone and became severe with salt spray time. The cross sectional morphology of both original and the shot peen-formed samples shows that severe intergranular corrosion occurred in the salt spray environment. However, for the original sample, the intergranular corrosion distribution was lamellar. For shot peen-formed sample, the intergranular corrosion distribution was network.

Effect of Shot Peening on the Strength and Corrosion Properties of EN AW 6082-T651 Aluminium Alloy

“…Aluminium and its alloys have been extensively used in many areas of industry, such as automotive, aerospace, shipping, sports, electrical, machinery and petroleum, primarily because of their light weight, good weight-to-strength ratio, excellent electrical and thermal conductivity, low cost, and corrosion resistance in non-aggressive environments [1][2][3][4][5][6]. Although a thin oxide layer naturally formed on the surface of an aluminium alloy could partially prevent corrosion attack, it is still susceptible to deterioration when exposed to an aqueous solution containing Cl -, F -, Iand Brions [1], [4,5].…”

“…In addition, poor fatigue resistance, low surface hardness and wear resistance are also insufficient for many requirements [3,7,8]. Therefore, additional surface protection of aluminium alloys is often essential and is usually achieved by various coatings applied on aluminium alloys [1,2,5] or other surface processing techniques, such as different methods of shot peening [4,[6][7][8][9][10][11][12][13][14] cavitation peening [15] and surface remelting [3,16].…”

“…Trdan et al [4] revealed that the corrosion resistance of AA2024-T3 could be improved by femtosecond laser peening in a 0.6 M NaCl test solution due to the compressive residual stress. Despite the improvement in corrosion resistance, Qiao et al [6] investigated the effect of shot peen forming on the corrosion resistance of 2024 aluminium alloy in a salt spray environment. It was reported that the salt spray corrosion resistance of 2024 aluminium alloy decreased after shot peening, with pitting corrosion occurring first in the crater lap zone and became more severe with increasing salt spray time.…”

Effect of Shot Peening on the Strength and Corrosion Properties of 6082-T651 Aluminium Alloy

“…Aluminium and its alloys are widely used in many areas of industry, such as the automotive, aerospace, shipping, sports, electrical, machinery, and petroleum sectors, primarily because of their light weight, good weight-to-strength ratio, excellent electrical and thermal conductivity, low cost, and corrosion resistance in non-aggressive environments [ 1 , 2 , 3 , 4 , 5 , 6 ]. Although a thin oxide film that naturally forms on the surface of an aluminium alloy can partially prevent corrosion attack, the presence of Cl − , F − , I − , and Br − ions in aqueous solutions causes the poor corrosion resistance of aluminium alloys [ 1 , 4 , 5 ].…”

“…In addition, their poor fatigue resistance, low surface hardness, and poor wear resistance also make them inadequate for many requirements [ 3 , 7 , 8 ]. Therefore, the additional surface protection of aluminium alloys is often essential and is usually achieved by various coatings applied on aluminium alloys [ 1 , 2 , 5 ] or other surface processing techniques, such as different methods of shot peening [ 4 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ], cavitation peening [ 16 ], and surface remelting [ 3 , 17 ].…”