Determining the Concentration of PAG Harden Solution for Solid Solution Treatment of Aluminum Alloy
Introduction
Aluminum alloy is a widely used material in many modern applications, including automotive, aerospace and architectural components and products. The materials possess excellent properties such as light weight, good strength-to-weight ratio, good machinability, corrosion resistance and good recyclability. Due to its high thermal conductivity and host of other desirable properties, aluminum alloy is commonly used as a building material for bridge decks, pressure vessels, pipes and other structures and elements. To ensure that these components and products are able to withstand the extreme temperatures and corrosive environments in which they may be placed, it is necessary to employ various treatments such as solid solution treatment and heat treatment. The solid solution treatment makes use of a precipitation-aged hardening (PAG) solution, which serves to strengthen the aluminum alloy. This paper describes the method of determining the concentration of the PAG hardening solution for solid solution treatment of aluminum alloy.
Theory
When aluminum alloy components or products are subjected to solid solution treatment, they experience a strengthening process known as precipitation hardening. During this process, the aluminum alloy is subjected to the PAG hardening solution, which contains a combination of nickel and copper dissolved in an acid or alkaline solution. The nickel and copper dissolve in the solution, forming a complex solution of nickel and copper. This complex mixture forms complex oxides when heated, which then precipitate in the alloy. These precipitates serve to increase the strength of the aluminum alloy. The concentration of nickel and copper in the PAG hardening solution determines the degree of hardening achieved. Therefore, it is necessary to determine the concentration of the PAG hardening solution before treating the aluminum alloy in order to ensure the desired degree of hardening is achieved.
Methods
The concentration of the PAG hardening solution is determined by measuring the concentration of nickel and copper in the solution. This is commonly done using atomic absorption spectroscopy (AAS) or inductively coupled plasma atomic emission spectroscopy (ICP-AES). AAS is usually used for the detection of nickel and copper in the solution, while ICP-AES is used for the detection of compounds containing only one or two metals. To measure the concentrations of nickel and copper, a sample of the solution is taken and placed in a sample chamber. The chamber is then exposed to a beam of radiation, which causes the nickel and copper atoms to absorb the radiation and emit light of various wavelengths. The emitted light is then measured and used to determine the concentrations of nickel and copper in the solution.
Results
After measuring the concentrations of nickel and copper in the PAG hardening solution, the concentration of the PAG hardening solution can be determined. For example, if the measured concentrations of nickel and copper are 0.8% Ni and 0.2% Cu (by weight), then the PAG hardening solution is 1% Ni-0.2% Cu by weight. This concentration can then be used when treating the aluminum alloy in order to achieve the desired degree of hardening.
Conclusion
The concentration of the PAG hardening solution is important in order to achieve the desired degree of hardening when treating aluminum alloy. This paper has described the method of determining the concentration of the PAG hardening solution for solid solution treatment of aluminum alloy. The concentrations of nickel and copper in the solution can be determined using either atomic absorption spectroscopy or inductively coupled plasma atomic emission spectroscopy. The concentration of the PAG hardening solution can then be calculated based on the measured concentrations of nickel and copper in the solution.
