A Study of the Effects of Aluminium Alloy Castings Quality from Metal Liquid Surface Oxide Film
Introduction
Formation of oxide films on the surface of aluminium alloy castings is an inevitable phenomenon during the manufacturing process. This film affects the performance of the final product quality by prohibiting the transfer of heat and inducing stress. Since this is a significant problem for the industry, it is important to understand and investigate further how the oxide film impacts aluminium alloy castings. The goals of this research is to determine how the oxide films influence the quality and structural integrity of the alloy castings. Specifically, this research will examine the impacts of oxide films on the mechanical strength and conductivity of aluminium alloy castings.
Background
High-alloy aluminium alloys are commonly used in large-scale product applications in aerospace, maritime, vehicle and other industries. The majority of product performance and operational requirements are achieved through the precise processing of aluminium alloys. Thus, the quality of aluminium castings has a direct impact on the product production process and its performance. There is a need to ensure that the alloy castings are made using appropriate methods and materials to ensure product reliability.
During the production of aluminium alloy castings, the surface of the molten metal is covered with a layer of oxide film. This film is usually formed due to the dissolution of oxygen into the melt and the oxidation of the alloy itself. Oxide films can have a great effect on the quality of the alloy castings. For example, if the oxidation process is too severe, the surface of the finished product may contain a lot of trapped oxides. These oxides can damage the resistance and strength of the alloy. They can also make the surface of the product rough and reduce its mechanical properties.
In addition to the quality issues associated with oxide films, they can also create unwanted stresses and distortions when the product is cooled down during the cooling process. The presence of oxide films on the surface of the product can cause local strains to be introduced to the final product, thus leading to an increase in the bending and corrosion resistance of the alloy castings.
Experimental Methods
In order to determine the impact of oxide film on the quality and structural integrity of aluminium alloy castings, a series of experiments have been conducted in four stages. Starting with comparing two types of oxide film: a common oxide film and a controlled oxide film. Then, the samples were assessed vis-à-vis their mechanical properties and conductivity.
Stage 1: Sampling
The experiment samples used in this study consist of two categories of alloy castings: one with a common oxide film, and one with a controlled oxide film. Each category contains four samples of alloy castings with the same chemical composition and dimensions. This allows comparison between two types of oxide film in the same alloy.
Stage 2: Analysis of the Oxide Film
In the second stage of the experiment, the thickness of the oxide film on each sample was measured using a scanning electron microscope. This allows for comparison between the two types of oxide film samples and the formation of quantitative results.
Stage 3: Mechanical Property Analysis
In this stage, the mechanical properties of both types of samples were analysed using tensile testing and hardness testing. The tensile strength and elongation of the samples were measured, and the hardness was evaluated using a Rockwell hardness test. This testing allows for the comparison between both types of samples.
Stage 4: Conductivity Analysis
The fourth stage of the experiment involved the analysis of the conductivities of each of the samples. The conductivity of the alloy castings was measured using an alternating current resonance impedance meter. This method allows for the evaluation of the diffusion of the electrons through the material.
Results and Discussion
The results of this study speak to the effects of oxide films on the quality and structural integrity of the alloy castings. The results show that the controlled oxide film samples had higher levels of tensile strength and hardness than the common oxide film samples. The conductivity of both types of samples was within an acceptable range, but the controlled oxide film samples had higher conductivities than the common oxide film samples.
Conclusion
This study provides a basis for understanding the impacts of oxide films on aluminium alloy castings quality. The results indicate that the presence of a controlled oxide film may be beneficial for improving the tensile strength, hardness and conductivity of the alloy castings. Further research is needed in order to gain a better understanding of the effects of oxide films on alloy castings, as well as how to optimise these films for better quality alloy castings.
