- February 21, 2017
- Posted by: Roger Walker
- Category: Reviews
Modern tools push the thermal limits of the materials from which they’re made. Some suffer mechanical friction (such as drill bits and space shuttle nose cones), some electrical heat (like lasers and computer processors) and some are assaulted by heat sources they contain (such as nuclear reaction chambers). All of them must be cooled one way or another – or fail.
Without heat control, instruments become inaccurate – potentially disastrous in medical or manufacturing scenarios or in computers. Components also age faster because of micro-fractures caused by expansion and contraction, or meltdown or seize up, potentially causing serious burns to their users. Most perform worse outside of a narrow temperature range – pushing up overheads.
Heat-sinks and Thermal Adhesives
Heat dissipation requires a material that radiates or convects away the heat (the heat-sink) and another to bond that sink tightly to the heat-stressed substrate – such as a metal bonding adhesive. Because heat control is such a ubiquitous and critical issue, both sinks and adhesives are the focus of intense R&D.
The adhesive must maintain contact between the hot body and its sink under challenges of temperature, vibration and chemical exposure. It must retain excellent conductivity across that range of variables too. An epoxy, for example, must have flexibility so that it neither cracks nor loses contact.
Designing machinery for heat control involves complex trade-offs between temperatures, material life-span and cost, as well as the performance, bulk, weight and other characteristics of additional thermal dissipation materials. It’s therefore necessary to consult specialists such as http://www.ct1ltd.com/ to help identify the best solutions for specific situations.
Technology is changing rapidly. Metallic infused epoxies may be replaced by ones based on graphene. Carbons have less weight, greater stability, and higher melting points – graphene’s is approximately the same as the temperature of the Sun.
Some heat sinks already use Annealed pyrolytic graphite (APG) instead of just metal. Soon there’ll be carbon nano-tube and graphene sinks.
The future may see metal wiring in circuits replaced with carbon fibres and components printed using graphene “inks” that run cooler in the first place (or will run faster for the same heat load). In mechanical settings, carbon lubricants and 3D printed carbon components could generate less heat from friction than our heavier existing machinery.