Engineering Alloys (Ferrous And Non-Ferrous)

INTRODUCTION

Out of solid materials utilized in engineering practice metals, plastic and ceramics are very common. Then metals might be used in their elemental forms like aluminium, copper and titanium. While a metallic element has additives much smaller in quantity than base element, the resulting material is called an alloy of base element. Out of all metallic elements it is iron whose alloys are utilized in largest quantity. All of such alloys in which iron forms the base are grouped as ferrous material. The other alloys are grouped as non-ferrous materials.

Ferrous materials, both of  metal and alloys have iron as their base and due to wide range of their properties are most useful for use in engineering machines and structures. Owing to the advents in steel technology and casting technique ferrous metals are cast, shaped and machined in many shapes & sizes. Several standard shapes of sections are variable     commercially which make the job of designer and constructor much easy. They are utilized for making bridges, trusses, ships and boilers. For such type of construction standard section and sheets of plats of steel are available. The other machine parts as gears, shafts, bearings, pulleys & bodies of machines might be made in steel through forming, cutting or casting processes or combination thereof. Metal cutting tools, punches, dies, jigs and fixtures are also built in ferrous metal. One of the largest consumers of steel is automobile industry. Perhaps in countries like USA where cars of bigger size are in use this weight could be as high as 800 kgf/car.

The first human effort in the direction of making tools was based upon meteoritic iron obtained from meteorite that had struck the earth. This happened more than 3000 BC.. The future trend is to replace steel by plastics in many machines and equipment. This target has been obtained in a number of home appliances. The demand for steel is level since 1965. Cost fluctuations in most of metals have been controlled. The similar is true for steel whose cost is increasing at constant rate since early eighties. The comparative price of various metals with piece of gold at 1000 is given in Table 1.

Table: Approximate Comparative Prices of Various Metals with Gold Piece of 100 as Base (per Weight)