MATERIALS AND HARDWARE

Introduction

This module will deal with a broad group of materials and hardware that are used in aircraft engineering. These materials can be classed into the three main categories of Ferrous Metals, Non-Ferrous Metals and Non-Metallic materials. Additionally, combinations of many of these materials are being used in the aerospace industry.

The usefulness of any materials may be enhanced as a result of the addition of other materials that alter the basic characteristics to suit the specific requirements of the aircraft designer. A metal’s usefulness is governed principally by its physical properties. Those properties depend upon the composition of the metal, which can be changed considerably by alloying it with other metals and by heat-treatment. For example, the strength and hardness of steel can be intensified by increasing its carbon content, adding alloying metals such as Nickel and Tungsten, or by heating the steel until red-hot and then cooling it rapidly.

Apart from the basic requirement of more and more strength from metals, other minor characteristics can also be added, when such features as permanent magnetism, corrosion resistance and high-strength whilst operating at elevated temperatures, are desired.

Composites make up a large part of the construction of modern aircraft. In the early days, composites and plastics were limited to non-structural, internal cosmetic panels, small fairings and other minor parts. Today there are many large aircraft, which have major structural and load-carrying parts manufactured from composites. In addition to maintaining or increasing component strength, composite materials contribute to the important factor of weight saving. There are also many modern light aircraft that are almost totally manufactured from composites and contain little metal at all.