Basalt Fiber Based Sheet Molding Compound and Composites for Automotives

The motivation of present research is to evaluate the potential of Basalt fiber based Sheet Molding Compound (SMC) as a novel and cost effective material form for the use of composites in automotive applications for net-shape production and light weighting. The present paper reports results from our ongoing research on the feasibility trials for introducing Basalt fibers in sheet molding compounds through material manufacturing trials, panel fabrication, testing and comparison to current SMC materials. The technical approach included: Multi-Scale Characterization of Basalt fibers and Interface Shear Strength, Evaluation of Tow Properties, Manufacturing of SMC using Basalt fibers, Fabrication of test panels from SMC containing Basalt fibers, Characterization of the physical and mechanical properties of the Basalt fiber SMC test panels, and finally the Comparison of the Basalt containing SMC with standard SMC containing glass fiber as a reinforcement. The sheet molding compounds were formulated by Hexion using Mafic Basalt Fiber with optimized sizing and suitable resin systems and the composite panels were provided to the authors for its detailed characterization at the University of Tennessee, Knoxville. Multi-scale characterization work started with evaluating single basalt fibers using a very unique nano-tensile testing system. Through CSM (Continuous Stiffness Measurement), dynamic properties are determined throughout deformation process of single basalt fibers, and highly precise tensile modulus as well as its variation with axial strain till failure was obtained. Suitable number of single fibers were evaluated to obtain a two parameter (shape and strength) Weibull statistics for a gage length of 25 mm.