Design and manufacture of automotive components in thermoplastic composite (Part II)

Abstract

The thermoplastic RTM process (T-RTM) is currently one of the most demanded process for R&D in the automotive sector. This sector tries to lighten the weight of the vehicle with highly resistant non-metallic components and with efficient manufacturing in cycle-time and cost. In the framework of the BIHARKONP project, EDERTEK-TECNALIA proposes the migration of a suspension arm, currently manufactured by means of metal stamping, to high mechanical requirements composite materials, obtaining a weight reduction of 30%. For the manufacture of this component it was proposed to redesign the component in carbon fiber (CF) and polyamide 6 matrix (APA6). The redesign (Part I) consisted in a mechanical calculation of the loads that the component had to support. The geometry has been changed with the aim of fulfilling the part specification and the peculiarities of the T-RTM process. For the manufacture of the component, a CF/APA6 composite laminate was defined and characterized and a specific CF for thermoplastics was selected. Subsequently, a T-RTM mold was designed and manufactured with inserts for fiber compaction and eight thermal control zones. The geometry of the control arm involves the manufacture of CF preforms by means of a thermal forming process with thermoplastic veils. Caprocast technology has been used to manufacture the prototype by caprolactam injection and its polymerization inside the heated mold. The prototype was subjected to bearing test, bushing insertion-extraction test and bushing strength test. The component was validated.