Whilst DIMAR have produced carbide tools for the composite market for many years, we now introduce a new range of tools, including CVD coating and diamond-plated options that offer the market more effective solutions. With our propriety grades of carbide, we can offer the industry significant improvement in tool life-time, cutting quality and cost.
We are confident that DIMAR can provide producers working with composite producers, the most cost-effective tooling solutions, along with the highest quality and the full service back up that go beyond expectations.
Composite materials
Composite materials are made from reinforcing fibers and a polymer matrix, which serves to bind the two materials together. When combined these two individual materials form a single material that has many desirable characteristics including very high specific strength, corrosion resistance, impact resistance, and excellent durability.
FRP fiber REINFORCED plastic
Today’s most popular composites use reinforcing fibers such as fiberglass, carbon, and aramid and are held together by a matrix of plastic resin that can be thermoset or thermoplastic.
Difficulties in machining composites
Tool life
While these fibers offer great strength and durability to composite components they are also extremely abrasive and therefore negatively impact tool life.
Machining heat generation
Not all plastic matrix materials can withstand the heat generated during the machining of parts made from composites. Excessive heat generated during machining can melt the polymer matrix and damage the composite if care is not exercised.
Composite delamination
Components made from composite materials can be very susceptible to delamination caused by machining. The damage may not be apparent to the naked eye but under magnification separation of the layers caused by the tool can be seen. This damage can be caused by excessive tool wear and improper tool selection.
DIMAR has recognized the challenges of machining composite materials and have developed a group of tools that offer solutions to these demands.
With over 60 years’ experience in developing and manufacturing cutting tools for diverse applications and industries, DIMAR has used this experience to create cutting tools that can offer greater benefits over competition and meet the challenges faced by users machining modern composite materials.
Chip direction
The DIMAR tool range allows the user to select the chip direction based on part geometry and composition. By choosing the correct helix angle the user can optimize the cutting quality and minimize chipping. Selections include right hand helix (up shear), left hand helix (down shear), straight helix and a combination of up shear and down shear on the same tools.
Multi-flute tools
Tools that are designed to machine composite materials will have more flutes than the tools for wood, aluminum or steel. With more cutting surfaces engaged in the part, the load on each cutting edge is reduced. As a result, tool life and finished part quality is significantly increased. DIMAR Multi flute tools are highly recommended for machining of thin composite materials since delamination risks are reduced.
Part penetration
DIMAR’s geometry at the tool end provides the ability to penetrate the part the moment the tool starts working. The large number of tool flutes limits the chip out flow during initial penetration. For this reason, it is recommended that a spiral motion is used.
Through holes
For through-holes in composite parts, DIMAR recommends that a head of between 20-90 degrees be used when manual drilling is used. This geometry will provide the highest quality edge finish overall. For controlled feed drilling it is suggested that a tool with “up shear” helix be used.
CVD (Diamond) Tools
Some composite machining applications will require the use of high end tools referred to as CVD tools. DIMAR’s CVD (chemical vapor deposition) tools are comprised of 100% pure diamond permanently embedded on to tungsten carbide. The diamond coating can be applied at a thickness of 3-30 micron depending on the specific application.
DIMAR’s CVD tool range offers advantages and benefits when compared to traditional steel tools. Diamond, with its renowned reputation for hardness, offers significantly enhanced wear resistance in addition to a lower coefficient of friction and better heat dissipation. CVD tools have been known to last up to 10 times longer than regular tools. In certain applications using a CVD tool may require higher tool speeds (100 - 200% faster than non-CVD tools) as well as higher feed rates (70-150% faster).