Evaluation of Some Orthopaedic Materials

Mechanical properties of some orthopaedic products—Alpha—plast, Barplasty, CFB, and Durament were evaluated. After polymerising into plaques, test samples were ma chined into coupons. Notched specimens were fractured under tension using the IN- STRON. Fracture toughnesses, fracture energies and tensile stresses were subsequently calculated. Fractography revealed that toughness and fracture energy correlated with duc tility and cohesion. Tougher materials tended to show more transgranular fracture, though the intergranular mode was also observed. The KEVEX unit indicated Zr and some Si was present. Dispersed non-spherical particles were also seen in SEM micrographs. Tough nesses and energies were lower than those reported earlier [1] . Voids, incoherent inter faces, larger notch widths, and lubrication by filler particles could result in lowered yield stress and toughness. The method of preparation, initial particle size distribution, and ac tivating agents also affect properties [2-5].