Surfi-Sculpt is a revolutionary materials processing technology developed at TWI. A power beam is used to generate precisely defined textured surfaces in a matter of seconds per cm2.
This novel power beam materials processing technology creates carefully designed features across a surface, using a laser beam or an electron beam, although the latter process variant is significantly more advanced in its development and has been used in the vast majority of tests to date.
The beam is deflected rapidly over a substrate surface to displace material in a controlled manner. The result is a textured surface consisting of an array of protrusions above the original surface and a corresponding array of intrusions or cavities in the substrate. The process can be used to produce high aspect ratio spikes up to 2mm in height, as well as blades, channels, swirls and burr-free holes in a range of metals, polymers, ceramics and glasses. The process takes just a matter of seconds per square centimetre with the size, shape and distribution of the features all able to be varied to produce a surface tailored for specific applications.
When the beam comes into contact with the substrate surface it creates a molten pool of material. If the beam is then translated sideways, the combined effects of vapour pressure and surface tension allow the material from the hole to be piled up behind the beam. By repeating this process many times at the same site, protrusions of the order of 2mm in height and 0.2mm in width may be grown, with each being accompanied by one or more corresponding intrusions or holes. A whole series of protrusions can be built up simultaneously across a substrate. With careful control of the beam process parameters (beam accelerating potential, beam current, focus, etc), the design of a unique pattern and precisely defined deflection movements, it is possible to create a wide variety of different surfaces.
The features that can be created using Surfi-Sculpt include:
- High aspect ratio features
- Honeycomb structures
- Hollow conical features
- Multiple stage treatments
- Fine-scale fins
- Holes/slots with no burrs on the reverse
Because the process is highly flexible, it offers the opportunity to design customised surfaces for any application.
Applications
Surfaces produced with the Surfi-Sculpt process have shown potential for the following applications:
- Composite to metal bonding (also known as ComeldTM)
- Promotion of adhesive bonding
- Bonding and direct moulding of polymers to metal parts
- Manufacture of aerodynamically enhanced surfaces
- Manufacture of hydrodynamically enhanced surfaces
- As a preparation prior to surface coating
- Manufacture of filters and other applications requiring shaped slots and holes, e.g. for mixing of gases and/or liquids
- Manufacture of surfaces with enhanced thermal properties
- Manufacture of tailored surfaces with specific wave interaction, absorption, emission and/or propagation properties
- Manufacture of locally alloyed functional surfaces with specific mechanical, electrical, magnetic, thermal chemical, and other properties
- A prototype liquid cold plate heat exchanger (courtesy of Thermacore Europe)
TWI would welcome collaboration with potential industrial users of the technology in any of the above application areas.