Degradation Behavior of High Chromium Sodium-Modified A356.0-Type Al-Si-Mg Alloy in Simulated Seawater Environment

Abstract

The effect of multiple-step thermal ageing treatment (MSTAT) on the corrosion characteristics of A356.0-type Al-Si-Mg alloy in simulated seawater has been studied. The MSTAT treatment also consists of Double Thermal Ageing (DTAT-T7), Single Thermal Ageing (STAT-T6), Step-Quenching and Ageing (SQA). The corrosion of the thermal treated samples was characterized by electrochemical Potentiodynamics polarization techniques consisting of linear polarization and chronopotentiometric method using the fit Tafel plot. Generally, from the linear polarization, the corrosion rate decreases at all temperatures with the ageing time. The corrosion behavior of the DTAT and SQA Al-Si-Mg alloy in the simulated seawater showed better resistance than the STAT Al-Si-Mg alloy. Samples in the SQA-STAT have improved corrosion resistance than the SQA-DTAT one. The chronopotentiometric corrosion study of some selected samples indicates a decrease in the corrosion resistance with open circuit potential exposure time. Consequently, the form of corrosion in the studied Al-Si-Mg alloy are slightly uniform and predominantly pitting corrosion as obtained from the SEM study. The pits diameter were found to range from 30-50µm.

The influence of Cu doped on structure and mechanical properties of aluminium material

“…In the development aluminium alloys, various results have been published on the structure, mechanical properties [1][2][3][4] and their degradation at various conditions of the alloys [5][6][7][8][9]. Several methods of processing of aluminium alloys have been demonstrated by different authors [2,5,8,[10][11][12][13][14]. Alloying addition have been reported to successfully enhanced the aluminium alloy properties such as corrosion resistant and mechanical properties [5,15,16].…”

“…Several methods of processing of aluminium alloys have been demonstrated by different authors [2,5,8,[10][11][12][13][14]. Alloying addition have been reported to successfully enhanced the aluminium alloy properties such as corrosion resistant and mechanical properties [5,15,16]. The aluminium alloy containing Al-Mn and Al-Mg [5] alloys are the least resistant to corrosion under various conditions.…”

“…Alloying addition have been reported to successfully enhanced the aluminium alloy properties such as corrosion resistant and mechanical properties [5,15,16]. The aluminium alloy containing Al-Mn and Al-Mg [5] alloys are the least resistant to corrosion under various conditions. In this paper we have investigated pure aluminium (Al) containing various copper (Cu).…”

Effect of double thermal ageing treatment on the mechanical properties of Al–Cu–Mg/3% rice husk ash composite

“…7 In recent time, it has been shown that RHA can be used as reinforcement in Al-Cu-Mg composite and by varying the percentage composition and particle size of the RHA, the RHA is absorbed by the alloy up to 3% by weight and with 150 microns particle size a combination of good properties can be obtained. [9][10][11][12] For the purpose of this study, a two-step ageing treatment (Double Thermal Ageing Treatment; DTAT) was developed for Al-Cu-Mg/3%RHA composite…”

Effect of Cu content on the Electrochemical Corrosion Behavior of Peak-aged Al-6Si-0.5Mg Alloys in Sodium Chloride Solution

“…This film protects the metal from further oxidation unless this coating is destroyed, and the material remains fully protected against corrosion [3]. The composition of an alloy and its thermal treatment are important do determine the susceptibility of the alloy to corrosion [4,5]. Over the years a number of studies have been carried out to assess the effect of Cu content and the distribution of second phase intermetallic particles on the corrosion behavior of Al alloys.…”