5.3 Modern Materials


  • Modern Materials: Materials developed by engineers and scientists through research and experimentation. They are typically designed to perform specific functions and are often discovered by accident.

    • Key Characteristics:

    • Developed for specialist applications.

    • Enhanced properties make them suitable for a range of products.

Examples of Modern Materials:

  • Kevlar

  • Polymorph

  • Precious Metal Clay

  • High-Density Modelling Foam

Kevlar

  • Definition: Kevlar® is a high-performance aramid fibre spun into a thread and woven into fabric.

  • Key Properties:

    • Stops bullets and provides thermal protection at temperatures over 120°C.

    • Lightweight, hard-wearing, extremely strong, and stiff.

    • Heat and chemical resistant.

    • Approximately five times stronger than steel.

  • Applications:

    • Used in bulletproof vests.

    • Other potential uses include high-performance protective clothing and accessories.

  • Initial Purpose: DuPont required a strong, stiff, and lightweight material to replace steel reinforcements in tires.

  • Current Usage:

    • Apart from protective clothing, Kevlar fibres enhance composite materials used in various high-performance applications.

Increased Safety and Efficiency with Kevlar

  • Properties:

    • Excellent impact resistance and tensile/torque strength.

  • Applications in Vehicles:

    • Used in high-performance vehicles (land, sea, air) to produce stronger, lighter, and safer products.

    • Example: The Eurofighter utilizes material reinforced with Kevlar, allowing greater fuel efficiency and speed.

Modern Material: Polymorph

  • Definition: Thermoplastic modern material that becomes malleable at low temperatures.

  • Properties:

    • Becomes easy to mould by hand when heated in water to 62°C.

    • Can be remoulded multiple times; becomes very tough and durable upon cooling.

    • Comparable to nylon in terms of durability and toughness.

    • Non-toxic and biodegradable.

  • User-Friendliness:

    • Safe and easy to use, especially at home.

Applications of Polymorph

  • Common Uses:

    • Personalized ergonomic products and parts like handles, orthodontic moulds, and gum shields.

  • Target Users:

    • Particularly useful for the elderly, those with disabilities, or individuals with deformities.

Modern Material: Precious Metal Clay (PMC)

  • Definition: Made from particles of precious metals suspended in a water-based non-toxic organic binder.

  • Properties:

    • Can be shaped by hand or moulded like traditional modelling clay.

    • The binder is burnt off during the firing process, resulting in a product that is over 90% precious metal.

    • Experiences a shrinkage of 5-15% during firing.

  • Comparison with Traditional Techniques:

    • What are the benefits of using PMC over traditional metalworking techniques?

Pros and Cons of PMC

  • Advantages:

    • Accessible material with low tool requirements and minimal metalsmithing skills needed.

    • Easy to work with, allowing for quick production with options for firing in kilns or butane torches.

    • Allowance for stone setting and joining with slips.

  • Disadvantages:

    • Can dry out if overworked or improperly stored.

    • Not as strong as sterling silver.

    • Generally more expensive than traditional materials, albeit with lower setup costs.

Modern Material: High-Density Modelling Foam (HDMF)

  • Definition: A strong and lightweight rigid material used for creating high-quality 3D models.

  • Properties:

    • Retains good surface detail; compatible with fillers, primers, and paints for finishing.

    • Can be CNC milled, routed, or shaped manually.

    • Efficient for producing moulds for vacuum forming and low-temperature metal casting.