The automotive industry has experienced rapid development in recent years, with a significant increase in the number of vehicles in China. To effectively reduce the energy consumption and carbon emissions of automobiles, implementing lightweight design for the steering knuckle structure is essential. In this paper, in order to prepare steering knuckle parts with less weight, the material of steering knuckle was changed from 40Cr to polyether ether ketone (PEEK), which has less density, while maintaining the performance of the part. Fused deposition molding (FDM) technology, as one of the main methods of thermoplastic material manufacturing, has the ability to machine any complex geometrical structure, which greatly enhances the degree of design freedom. However, in the case of FDM technology, the print parameters determine the performance of the printed sample. Based on this, this paper will explore the influence of process parameters on the mechanical properties of PEEK materials through orthogonal experiments to screen out the optimal parameter combinations for printing. For the printing layer height of 0.1mm, the temperature of the holding chamber is 90 ℃, the filling method for the spiral tetrahedron. The PEEK materials molded under the optimal parameters of FDM were insulated to investigate the effect of the heat treatment process on the mechanical properties of PEEK materials. The loaded condition of the steering knuckle in each working condition is calculated by the basic parameters of the car, the dangerous cross section of the part is determined by simulation, and the structural optimal design of the part is carried out by topology optimization. Under the premise of ensuring its mechanical properties, minimize the amount of material to achieve the goal of lightweight.

Two sets of nine different silicon carbide particulate (SiCp) reinforced Al 7075 Metal Matrix Composites (MMCs) were fabricated using liquid metallurgy stir casting process. Mean particle size and weight percentage of the reinforcement were varied according to Taguchi L9 Design of Experiments (DOE). One set of the cast composites were then heat treated to T6 condition. Optical micrographs of the MMCs reveal consistent dispersion of reinforcements in the matrix phase. Mechanical properties were determined for both as-cast and heat treated MMCs for comparison of the experimental results. Linear regression models were developed for mechanical properties of the heat treated MMCs using list square method of regression analysis. The fabrication process parameters were then optimized using Taguchi based grey relational analysis for the multiple mechanical properties of the heat treated MMCs. The largest value of mean grey relational grade was obtained for the composite with mean particle size 6.18 µm and 25 weight % of reinforcement. The optimal combination of process parameters were then verified through confirmation experiments, which resulted 42% of improvement in the grey relational grade. Finally, the percentage of contribution of each process parameter on the multiple performance characteristics was calculated through Analysis of Variance (ANOVA).