Properties and Structure of AlZnMg/Steel Fibre Composite Material

Editorial Note and Synopsis

This paper does not fall within the usual strict definition of cast metals science and technology, since it is concerned with a wholly solid-state process. It has, however, been accepted for publication in Cast Metals, since its treatment of the influence of fibre reinforcement on mechanical properties of a light alloy is considered to be pertinent to the growing understanding of the behaviour of composites, whether wrought or cast, as a major group of essentially new materials.

In this paper, the author examines the properties of a composite material with a matrix of hardenable AlZn4Mg1 alloy, reinforced by maraging steel fibres. For the purpose of the investigation the material was produced from layers of steel reinforcement fibre, interleaved with aluminium foil, which were subsequently hot pressed under vacuum. It was found that the presence of reinforcement fibres increased the strength by approximately twice the initial value. Nevertheless, the theoretical strength and Young's Modulus were about 15% higher than the values obtained. This was thought to be due to the considerable heterogeneity of the matrix. The reinforcement steel exhibited plastic behaviour, the matrix condition depending on the type of ageing. The diffusion layer on the fibre surface exhibited brittle fracture.