Figure 1 shows the aluminum alloy control arm. The material is A356.2 alloy, and the maximum overall dimension is 320mm × 154mm, with an average wall thickness of 12mm. The structure is optimized according to the topology, the skeleton is extracted, and the rod structure with arc bending shape is finally designed in combination with the assembly requirements. The assembly stress relationship exists at three positions. The stress analysis of the optimized structure shows that the stress and deformation meet the design requirements.
The overall mass of aluminum alloy casting is 2.5kg. From the structural characteristics of the casting, the casting has simple structure and moderate wall thickness, which is suitable for squeeze casting. Fig. 2 is a schematic diagram of the casting arrangement system of squeeze casting. Figure 3 shows the structure of local extrusion. Figure 4 shows the dynamic model waterway structure. Fig. 5 is the X-ray flaw detection of squeeze casting control arm. It can be seen from Fig. 5 that no shrinkage cavity and shrinkage porosity defects are found in other parts of the squeeze casting control arm except for slight shrinkage porosity at the large hole.
Fig. 6 is the microstructure of the control arm casting under the extrusion specific pressure of 100MPa. It can be seen that the microstructure of squeeze casting control arm is α＋ Eutectic, under the condition of squeeze casting, the solidification rate of the casting is increased due to the existence of extrusion force α The phase was refined to some extent.
Taking samples from the control arm casting body for mechanical property test, it is found that the mechanical properties of each position of the casting are equivalent, the tensile strength is greater than 300mpa, the yield strength is greater than 230MPa, and the elongation is greater than 8%. Meet the design requirements. After 1 million bench tests, the performance indexes of the product fully meet the technical requirements, and the stiffness index is higher than the original steel castings.