Towards the Prediction of Tensile Properties in Automotive Cast Parts Manufactured by LPDC with the A356.2 Alloy

Abstract

Aluminum-silicon-magnesium alloys are commonly used in the automotive industry to produce structural components. Among usual quality controls of produced castings, microstructure characterization and determination of mechanical properties are the most critical aspects. However, important problems can be found when measuring mechanical properties in those areas of castings with geometrical limitations. In this investigation, a set of A356 alloys have been prepared and then used to manufacture test castings and automotive castings in a laboratory and in industrial conditions, respectively, using Low Pressure Die Casting (LPDC) technology. Test castings were used to predict secondary dendritic arm spacing (SDAS) by using thermal parameters obtained from experimental cooling curves. The results have been then compared to the ones found in the literature and improved methods for estimating SDAS from cooling curves have been developed. In a subsequent step, these methodologies have been checked with different industrial castings by using simulated cooling curves and experimentally measured SDAS values. Finally, the calculated SDAS values together with the Mg contents present in A356 alloys and the temperature and aging time data have been used to develop new models so as to predict the tensile properties in different areas of a given casting prototype. These developed models allow casters and designers predicting tensile properties in selected areas of a given prototype casting even during design and simulation steps and considering the processing variables expected in a given foundry plant. The structures of these new models have been described and experimentally validated using different processing conditions.

Low- and High-Pressure Casting Aluminum Alloys: A Review

“…The initial stages of solubilization (540°C for 6 h), quenching in water (at 40°C), and finally artificial aging (155°C for 200 min) resulted in a similar microstructure as before. However, the Si particles become coarser and more rounded, as shown in Figure 2 f. With the increase in aging time and temperature, the UTS and yield strength (YS) tend to increase and elongation decreases due to the precipitation of very fine Mg 2 Si phases, which are not possible to observe by optical microscopy [9]. Concerning the HPDC parts, the microstructure is more refined than other casting methods due to the rapid filling and fast solidification.…”

“…The properties of Al-Si alloy castings are significantly influenced by several microstructure features, including secondary dendrite arm spacing (SDAS), bifilms, and porosities [9].…”

Optimizing the Gating System for Rapid Investment Casting of Shape Memory Alloys: Computational Numerical Analysis for Defect Minimization in a Simple-Cubic Cell Structure

“…Virtual casting analysis has gained increasing attention in the scientific community due to its advantages in terms of cost-effectiveness, shorter analysis time and reduced environmental impact compared to real casting tests. Several authors have contributed to this field by publishing studies employing numerical simulation to investigate fluid flow, solidification and defect formation in each stage of the casting process, including filling, injection and solidification [40][41][42][43][44][45]. These research efforts have played a significant role in advancing knowledge in this area and improving casting processes.…”