Multi-objective optimization of two-point incremental forming parameters for Ti-6Al-4V using taguchi approach

This study explores the optimization of essential process parameters in two-point incremental forming (TPIF) of Ti-6Al-4V titanium alloy using the Taguchi design method, in conjunction with signal-to-noise (S/N) ratio analysis and ANOVA, to enhance formability and surface characteristics. As the need for lightweight, high-performance, and customizable titanium components continues to grow in the biomedical and aerospace sectors, TPIF has emerged as a promising manufacturing method, offering high flexibility, cost efficiency, and minimal tooling requirements compared to traditional forming techniques. The study focuses on two critical response variables: forming depth and surface hardness. An L9 orthogonal array was implemented to evaluate the influence of three key parameters: step down, tool diameter, and contour path width. Experimental results indicated that tool diameter most significantly affected surface hardness, while step down was the dominant factor influencing forming depth. The optimal combination 0.3 mm step down, 10 mm tool diameter, and 6 mm contour path width produced a maximum forming depth of 8.35 mm and a surface hardness of 357 HV. The findings demonstrate that statistical design of experiments can successfully guide parameter selection to improve product quality, reduce material thinning, and minimize surface defects. Moreover, the integrated method ensures consistency, repeatability, and sustainable use of resources, making TPIF highly suitable for low-volume, high-precision applications such as patient-specific cranial implants and aerospace structural brackets. The study provides valuable insights for researchers and manufacturers aiming to advance incremental sheet forming technologies for next-generation materials