Effect of heating on the hardness of human bone.

Specimens of dry human bone wee subjected to gradual or sudden heating up to different temperatures. After heating they were cooled suddenly or gradually to room temperature. Their hardness was studied by the Vickers and ball indentation tests. The deformation produced was studied by interferometric and phase-contrast techniques. Heating caused the bone to become brittle without any considerable changes in the surface features. Gradual cooling induced surface hardening. Heating was not found to affect indentation-induced surface distortion.