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The Basics of Nonferrous Metallurgy

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Solidification Processing of Sn-Pb Alloys in Magnetic Fields: Part One

The solidification process of metals provides an important opportunity to influence several key characteristics of the final product. Using magnetic fields can result in key benefits including improved metallurgical structure, reduced inclusions and improved mechanical properties to name but a few.

Solidification Processing of Sn-Pb Alloys in Magnetic Fields: Part Two

A wide range of detailed numerical simulations have been developed to help predict the influence of the electromagnetic convection on the solidification of Sn-Pb alloys.
The role of melt convection has also been studied during directional solidification of Pb-Sn alloys and shows a reduction of the boundary layer with electromagnetic stirring encouraging a thermal homogenization of the liquid bulk zone with affects being verified both in the macro- and microstructure.

Superplastic Aluminum Alloys

Superplastically formed (SPF) aluminum alloys have the ability to be stretched to several times their original size without failure when heated to between 470-520°C.
These dilute alloys containing zirconium, later to be known by the trade name SUPRAL, were heavily cold worked to sheet and dynamically recrystallized to a fine stable grain size, typically 4-5μm, during the initial stages of hot deformation.

Superplasticity of Aluminum Alloys: Part One

It is known that superplasticity refers to the ability of a material to demonstrate under tensile tests very high uniform deformation more than several hundreds percents without visible necking. There are two basic requirements in order to achieve superplastic flow in a polycrystalline material. First, the material must have a very small and stable grain size less than 10 μm. Second, superplasticity is achieved only at relatively high temperatures above 0.5Tm (where Tm is the absolute melting temperature) because superplasticity is diffusion-controlled process.

Superplasticity of Aluminum Alloys: Part Two

Investigations into the superplasticity possibilities of aluminums can lead to many potential gains in finding lighter yet capable materials in terms of strength performance.
This article covers the high-temperature deformation behavior of 5083 at different annealing temperatures and yields some interesting conclusions.

Surface Treatment Of Aluminum And Aluminum Alloys

Aluminum alloys are divided into two major categories: wrought and casting alloys. A further differentiation for each category is based primary on mechanism of property development. Many alloys respond to thermal treatment based on phase solubility. These treatments include solution heat treatment, quenching and precipitation, or age hardening.
In order to improve surface properties of final products, such as wear resistance, corrosion resistance, reflectivity etc., different types of surface treatment were designed. All of them are divided into several groups, such as electrochemical treatments, chemical treatments and coatings. In this article their terms and definitions will be explained.