Structure Optimization of Semi-Solid Die Cast Steering Knuckle and its Experiment Verification

Abstract:

Steering knuckles are vital functional and structural components in automotive suspension systems, requiring high strength, high ductility, and complex shapes. In this study, an aluminum alloy knuckle with the semi-solid die casting process was developed to replace the conventional steel components. This research aims to optimize product design based on both structural simulation and casting process simulation to avoid defects and to meet mechanical requirements. Furthermore, the optimal design solutions need to be verified through the filling experiments and defect analysis. The results show that the removal of support rib located in the thick area of the shock absorber mounting arm is helpful to avoid the rewelding defects in the filling frontier of the SSM melt. Besides, the position of the steering rod is of medium thickness, and two ribs from different directions come together to support that area. Rewelding defects were detected when two ribs come together. To avoid rewelding defects in local areas of steering rod position, the ribs were reduced to uniform wall thickness. Thus, the local flow state was modified and the SSM melt was reinforced shear action. Ultimately, by controlling all the processes of the SSM die casting process, the high performance of aluminum knuckle was successfully developed.

• Periodical: Solid State Phenomena (Volume 327)
• Pages: 149-155
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.327.149
• Online since: January 2022
• Authors: Song Chen*, Da Quan Li, Fan Zhang, Xiao Kang Liang, Jian Feng, Tao Li
• Keywords: Light Weight, Partial Fill, Semi-Solid Die Casting Process, Steering Knuckle, Structure Optimization

References

[1] Kim, G. Y., Han, S. H., Lee, K. H., Structural optimization of a knuckle with consideration of stiffness and durability requirements. ScientificWorldJournal 2014, 2014, 763692.

[2] Kang C. G., Lee S. M., Development of a new rheology forming process with a vertical-type sleeve with electromagnetic stirring. International Journal of Advanced Manufacturing Technology, 2008, 39(5-6):462-473.

DOI: 10.1007/s00170-007-1242-2

[3] Min Luo, Daquan Li, Wenying Qu, Xiaokang Liang, Jianzhong Fan, Effects of Cooling Rate and Grain Refiner on Semi-solid Rheocasting Slurries of Al–Zn–Mg Alloy, In Advances in Materials Processing, 2018; pp.829-837.

DOI: 10.1007/978-981-13-0107-0_81

[4] Kapranos, Current State of Semi-Solid Net-Shape Die Casting, Metals, 2019, 9(12):1301.

DOI: 10.3390/met9121301

[5] NADCA Product Specification Standards for Die Castings Produced by the Semi-solid and Squeeze Process, (2009).

[6] Nafisi S., Ghomashchi R., Semi-Solid Processing of Aluminum Alloys, Springer, (2016).

[7] Bolouri A., Bae J. W., Kang C. G., Tensile properties and microstructural characteristics of indirect rheoformed A356 aluminum alloy. Materials Science & Engineering A Structural Materials Properties Microstructure & Processing, 2013, 562(FEB.1):1-8.

DOI: 10.1016/j.msea.2012.10.099