Material is chosen with a product's design optimisation in mind. There have been many developments in the beginning of the 21st century that one now needs to consider when designing a product:
A product's material needs to be chosen with these points in mind. When a simple material does not fulfill the requirements, we can look to alloys (see Alloys) or create a composite (see Composites).
Example – Copper is the first choice of materials when looking for electrical performance under limited space conditions. The situation is different when you build a high-voltage line where weight and tensile strength are of central importance. The lighter and stronger the conductive material, the more space you can have between pylons. Copper is therefore displaced as the material of choice by a composite material composed of braided aluminum wires (as the lightest electrical conductor material) over a steel core (for high tensile strength).
Below are the main reasons that copper, copper alloys, and composites have so many existing uses and new applications are continuously being developed.