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Materials Science

4 min read

Part of Phase 5: Rebuilding Technology

Materials science explains what a material is rather than how to make it: grain size, phase and the presence of an interface account for most of what a metal, ceramic or plastic does, so the same iron and carbon can be file-soft or glass-hard depending on how it was cooled. The pages here sit beside the process articles. Stainless Steel Production and Aluminum Smelting cover the furnace work and the electricity, and these pages cover why the resulting metal behaves as it does.

Materials Science Principles, Crystal Structure, Grain Boundaries, Phase Diagrams, Mechanical Properties, Thermal Properties and Failure Modes cover the foundations. Halving the grain diameter raises the grain-size part of a metal’s yield strength by about 1.4 times, and the lever rule on the iron-carbon diagram shows a slowly cooled 0.40% carbon steel is about 51% pearlite.

Advanced Alloys, Stainless Steel, Austenitic Steel, Ferritic Steel, Aluminum Alloys and Bronze Alloys cover engineering metals beyond plain steel. Stainless needs at least 10.5% chromium, aluminium alloys climb from about 120 MPa to over 500 MPa through precipitation hardening, and bronze is best at 10-12% tin. Tool Steel has its own article in the industrial-production section.

Advanced Ceramics, Refractory Ceramics, Porcelain, Electrical Insulators, Chemical Vessels, Abrasives and Glass-Ceramics cover the non-metals that take heat, voltage and acid. Porcelain is fired at 1,260-1,400 °C so that feldspar melts and seals the pores, and a 300 mm grinding wheel at 1,500 RPM has a rim speed of about 23.6 m/s.

Composite Materials, Fiber-Reinforced Composites, Fiberglass, Natural Fiber Composites, Laminated Composites, Concrete Composites and Cermet cover combining materials. Hand-laid fiberglass gives 100-200 MPa at 1.5-2.0 g/cm³ against 7.8 for steel, and plain concrete’s tensile strength is effectively zero for design, which is why steel goes in the tension zone.

Polymer Engineering, Thermoplastics, Thermosets, Epoxy Systems, Phenolic Resins, Bioplastics and Rubber Compounding cover plastics and rubber. Whether a polymer melts, cures permanently or stretches depends on how its chains are linked, and a basic rubber compound carries 2-3 parts of sulfur per 100 parts of rubber.

Surface Treatments, Case Hardening, Precipitation Hardening and Galvanizing cover changing only the outer layer of a part. Pack carburising at about 900 °C for 2-8 hours gives a case of 0.5-2 mm, and a hot-dip zinc coating of 50-100 micrometres lasts 20-50 years in most environments.

Testing and Quality, Tensile Testing, Hardness Testing, Non-Destructive Testing, Dye Penetrant, Magnetic Particle and Metallography cover verifying what you made. A 10 mm bar of area 78.5 mm² that carries 31.4 kN has a tensile strength of 400 MPa, and a Brinell test with a 4.0 mm dent under 3,000 kg reads 229.

Principles

How structure produces properties, and how those properties are measured and lost.

Advanced Alloys

Engineering metals, and why each family behaves as it does.

Advanced Ceramics

Heat-resistant, insulating and chemically inert non-metals.

Composite Materials

Reinforcement in a matrix, from resin laminates to reinforced concrete.

Polymer Engineering

Thermoplastics, thermosets, bioplastics and rubber.

Surface Treatments

Protecting and hardening the outer layer of a part.

Testing and Quality

Measuring strength and hardness, finding flaws and reading structure.

45 items under this folder.