Theoretical and experimental investigation for enhanced thermo-mechanical and microstructural behavior of glass/carbon hybrids for automotive applications

The optimal combination of Glass (G) and Carbon fibres (C) in epoxy composites remains challenging due to the complexities in determining the maximum mechanical, thermal, and microstructural properties. This study investigates the effects of hybrid reinforcement to enhance performance for advanced engineering applications. Hand lay-up lamination method was employed in which the reinforcement was constant at 40 wt% for all the composition. The study examined three key processing factors: (i) Reinforcement (R) with six variations of 0 wt%, 40 wt% G, 40 wt% C, 10G/30 wt% C, 10C/30 wt% G 20G/20 wt% C; (ii) Nature of Fibre (NF) in woven, unidirectional, and chopped forms; and (iii) Temperature (T) at 30 °C, 50 °C, and 70 °C. Using the Taguchi optimization method, L18 experimental samples were prepared, with tensile strength selected as the response parameter. Validation tests including microstructural, thermal and mechanical tests were conducted on the best four samples from the optimization The experimental results identified sample R5NF2T70 as having the highest tensile strength (160 MPa). This was corroborated by the Taguchi optimization, which also predicted R5NF2T70 (10C/30G woven fibre cured at 70 °C) as the optimal combination. Reinforcement emerged as the most significant processing facto, followed by Nature of Fibre and Temperature. Further validation of the top four optimized samples (R5NF1T50, R6NF1T70, R6NF2T30, and R5NF2T70) revealed that while R5NF2T70 exhibited superior tensile strength, thermal stability, hardness and flexural strength among the selected samples. Microstructural analysis of R5NF2T70 indicated a well-integrated composite structure. The consistent identification of R5NF2T70 as the best overall performing composite, considering its balance of properties, suggests its suitability for high-strength applications in various industries.