Mechanical Hardness as a Probe of Nanocrystalline Materials

Micro-Tensile Testing of Nanocrystalline Al/Zr Alloys

A novel micro testing machine has been used to perform tensile tests on nanocrystalline Al/Zr microsamples with grain sizes ranging from 10 to 250 nm. The problems associated with testing such small specimens (200μm × 200μm in the gage section) were overcome by using a contact-free interferometrie strain gage (ISDG) and alignment and low friction loading were assured by use of a linear air bearing. The postulated relationship between yield stress and hardness was investigated and will be discussed. The effect of the microstructure and the grain size of the compacts on their mechanical behaviour are also analysed.