Contact-Damage Resistance of Partially Leached Glasses

Strength degradation characteristics of partially leached glass rods damaged in sharp contact are investigated. Residual compressive stresses in the outer layer (clad) of the treated rods inhibit the growth of surface cracks toward the inner region (core). The strength of rods indented quasi‐statically with a Vickers diamond pyramid shows functional dependences on contact load and clad stress in good agreement with predictions based on indentation fracture theory. The analysis identifies the degree of residual compression as the key parameter in the strengthening effect; however, in designing for high‐performance applications it may be necessary to optimize material properties (e.g. toughness, elastic moduli) and dimensions of the clad/core composite. Partial leaching, with its potential for developing high, uniform stresses over the clad thickness, may be advocated as a most useful means of obtaining high resistance to adverse contact conditions.