B. Ilschner

The influence of thermal and surface treatments on the anelastic creep of Al-Zn and Al-Cu alloys

Abstract In many industrial applications, like high precision force measurements or nanopositioning, the elastic and dimensional stabilities of materials are required at a nanometric scale. Therefore, some aspects of room temperature creep of commercial Al-Zn and Al-Cu alloys have been studied. The anelastic creep was measured at room temperature by means of a high resolution laser interferometer. The irreversible component of the deformation was quantified by measuring the viscoelastic after-effect. The anelastic relaxation of Al-Zn has been studied as a function of annealing time and temperature. The results are correlated with the size and the density of precipitates and the extension of the precipitate free zone. The influence of a surface treatment (sandblasting, electropolishing, Cu-galvanizing, chroming, Zn-plating) on anclastic relaxation has also been considered and explained in terms of the anelastic and elastic properties of both the surface layer and the bulk.

Anelastic relaxation in AI-4 Wt Pct Cu-AI2O3 fiber-reinforced composites

In many industrial applications, like high precision weighing and positioning, the elastic and dimensional stability of materials is required at a nanometric scale. High-resolution laser interferometry and mechanical spectroscopy have been employed to measure low-temperature anelastic creep of the short-fiber-reinforced composite Al-4 wt pct Cu-Al2O3. The typical strain resolution of the laser interferometer is 10-10. Fiber reinforcement has been found to increase the dislocation density in the metal matrix; in parallel, damping and anelastic creep are enhanced. This behavior has been explained on the basis of the structure of interparticle dislocations and θ′ relaxation.

Teaching materials science and engineering

This paper is written with the intention of simulating discussion on teaching materials science and engineering in the universities. The article illustrates the tasks, priorities, goals and means lying ahead in the teaching of materials science and engineering for a sustainable future.