Hybrid Taguchi–Gray Relation Analysis Method for Design of Metal Powder Injection-Molded Artificial Knee Joints with Optimal Powder Concentration and Volume Shrinkage

Abstract

Artificial knee joints play a critical role in improving the quality of life of the elderly and those with knee injuries. Such knee joints are fabricated using a composite material consisting of metal alloy particles and polymer resin and are generally produced using the metal powder injection molding (MIM) process. However, if the local powder concentration of the molded product is too low, the mechanical properties and aesthetic appearance of the joint are severely degraded. Similarly, if the product undergoes excessive shrinkage following removal from the mold, the dimensional accuracy will fail to meet the design specifications. Accordingly, the present study applies a hybrid approach based on the Taguchi robust design methodology and gray relation analysis (GRA) theory to determine the optimal MIM processing conditions that simultaneously maximize the powder concentration uniformity while minimizing the volume shrinkage. The feasibility of the proposed approach is demonstrated by means of CAE (Computer Aided Engineering) mold flow simulations. The results show that while the robust Taguchi design method enables the optimal processing parameters that maximize the powder concentration uniformity and minimize the volume shrinkage to be individually determined, the hybrid Taguchi–GRA method enables both quality measures to be optimized simultaneously.

Recent progress in minimizing the warpage and shrinkage deformations by the optimization of process parameters in plastic injection molding: a review

“…Additionally, a Taguchi method of L 9 integrated with computer-aided engineering (CAE) simulations were generated to find variability of procedure parameters of the injection molding considering the birefringence effect, and eventually, minimize the residual stress within the molded Fresnel lens and hence reduce its birefringence [75]. The present study integrated the Taguchi design method with Moldex3D simulations [76] to determine optimal injection molding processing conditions in a more efficient and versatile manner, which gave rise to a better aesthetic appearance of the final sintered product and an enhanced mechanical strength [67,77]. Meanwhile, multi-response optimization of PIM process parameters of polystyrene and polypropylene to minimize surface roughness and shrinkage using an integrated approach of S/N ratio and composite desirability function was put forward by Usman et al [78].…”

Integrating Taguchi Method and Gray Relational Analysis for Auto Locks by Using Multiobjective Design in Computer-Aided Engineering

“…The Taguchi gray relational analysis method is a multiobjective optimization analysis method. It can accurately improve the quality of multiobjective characteristics [ 17 , 18 , 19 ]. The S/N ratios obtained using the Taguchi method must be normalized.…”

Optimization of Ultrasonic Welding Process Parameters to Enhance Weld Strength of 3C Power Cases Using a Design of Experiments Approach

“…According to practical experience, drawbacks of the trial-and-error approach [22] include wasted time and random efforts. In this study, a cost-effective method for enhancing the weld strength of molded thermoplastic parts is proposed using the Taguchi methods [23]. Finally, the optimum process parameter was also verified by confirmation experiments.…”