Materials in Industry

Radical materials advances can drive the creation of new products or even new industries, but stable industries also employ materials scientists to make incremental improvements and troubleshoot issues with currently used materials. Industrial applications of materials science include materials design, cost-benefit tradeoffs in industrial production of materials, processing techniques (casting, rolling, welding, ion implantation, crystal growth, thin-film deposition, sintering, glassblowing, etc.), and analytical techniques (characterization techniques such as electron microscopy, x-ray diffraction, calorimetry, nuclear microscopy (HEFIB), Rutherford backscattering, neutron diffraction, etc.).

Besides material characterisation, the material scientist/engineer also deals with the extraction of materials and their conversion into useful forms. Thus ingot casting, foundry techniques, blast furnace extraction, electrolytic extraction all are part of the required knowledge of a materials scientist/engineer. Often the presence, absence or variation of minute quantities of secondary elements and compounds in a bulk material will have a great impact on the final properties of the materials produced, for instance, steels are classified based on 1/10th and 1/100 weight percentages of the carbon and other alloying elements they contain. Thus, the extraction and purification techniques employed in the extraction of iron in the blast furnace will have an impact of the quality of steel that may be produced.

The overlap between physics and materials science has led to the offshoot field of materials physics, which is concerned with the physical properties of materials. The approach is generally more macroscopic and applied than in condensed matter physics. See the important publications in materials physics for more details on this field of study.

Alloys of metals is an important and significant part of materials science. Of all the metallic alloys in use today, the alloys of iron (steel, stainless steel, cast iron, tool steel, alloy steels) make up the largest proportion both by quantity and commercial value. Iron alloyed with various weight percentages of carbon gives low, mid and high carbon steels. For the steels, the hardness and tensile strength of the steel is directly related to the amount of carbon present, while increasing carbon levels lead to lower ductility and toughness. The addition of silicon and graphitization will produce cast irons (although some cast irons are made precisely with no graphitization). The addition of chromium, nickel and molybdenum to carbon steels (more than 10%) gives us stainless steels.

Other significant metallic alloys are those of aluminium, titanium, copper and magnesium. Copper alloys have been know for a long time (during the Bronze Age), while the alloys of the other three metals have been relatively recently developed, due to the chemical reactivity of these metals and the resultant difficulty in their extraction which wasn't accomplished (electrolytically) until recently. The alloys of aluminium, titanium and magnesium are also known and valued for their high strength to weight ratios and, in the case of magnesium, their ability to provide electromagnetic shielding. These materials find special applications where high strength-weight ratios are desired (aero-space industry).

Other than metals, polymers and ceramics are also an important part of material science. Polymers are the raw materials (the resins) used to make what we commonly call plastics. Plastics really are the final product after a/many polymers and additives have been processed and shaped into a final shape and form. Polymers that have been around and are in current widespread use include polyethylene, polypropylene, polyvinyl-chloride, polystyrene, nylons, polyesters, acrylics, polyurethane, polycarbonates. Plastics are generally classified as "commodity", "specialty" and "engineering" plastics.

PVC is a commodity plastic, it is widely used, low cost and annual quantities are huge. It lends itself to an incredible array of applications, from faux leather to electrical insulation to cabling to packaging and vessels. Its fabrication and processing are simple and well-established. The versatility of PVC is due to the wide range of additives that it accepts. Additives in polymer science refers to the chemicals and compounds added to the polymer base to modify its physical and material properties.

Polycarbon would be normally considered an engineering plastic (other examples include PEEK, ABS). Engineering plastics are valued for their superior strengths and other special material properties. They are usually not used for disposable applications, unlike commodity plastics.
Specialty plastics are really the materials with unique characteristics, such as ultrahigh strength, electrical conductivity, electro-florescence, high thermal stability, etc.

It should be noted here that the dividing line between the various types of plastics is not based on material but rather their properties and applications. For instance, polypropylene (PP) is a cheap, slippery polymer commonly used to make disposable shopping bags and trash bags. It is commodity. But a variety of PP called Ultra-high Molecular Weight Polypropylene (UHMWPE) is an engineering plastic which is used extensively as the glide rails for industrial equipment.

Another application of material science in industry is the making of composite materials.
Composite materials are structured materials composed of at least two different macroscopic phases. An example would be steel-reinforced concrete. Also, take a look at the plastic casing of your telly set, cell-phone: these plastic casings are usually a composite made up of a thermoplastic matrix such as acrylonitrile-butadiene-styrene (ABS)in which calcium carbonate chalk, talc, glass fibres or carbon fibres have been added (dispersants) for added strength, bulk, or electro-static dispersion.