Why bond diamond? As most of us already know, diamond is the hardest material known to mankind. Most of us will have been told by an enthusiastic school teacher, “The only way to cut a diamond is to use another diamond.” As well as its coveted beauty which makes it one of the most valuable and sought-after gems, diamonds also have a great number of industrial uses.
Diamond grains are fixed on the functional part of the tool by a bonding material or some other method. Typical tools where diamonds are on the machining parts include diamond cutting tools, twist drill bits, grinding tools, saw blades, drawing dies, and diamond polishing pads. These can range in size from small, handheld cutting tools up to massive boring drills used in the mining industry.
Several methods of attaching them to other substrates include adhesive bonding, sintering, brazing, electroplating (by chemical vapor deposition method), and lastly, cemented carbide liners. Adhesives offer an effective yet low-cost method of bonding. They are ideal for bonding diamonds to a variety of different materials as desired (rather than have to incorporate various other joining procedures to work around different substrates).
Selecting an adhesive with the right characteristics is important to achieve optimum diamond bonding performance. Key features essential to successful diamond adhesive bonding include:
In summary, it is a “tool” order (!) to find an adhesive that ticks all the boxes. Generally, heat-cure single part epoxies with a specialist toughening matrix are the preferred choice for adhesive bonding of cutting tools, both for bonding diamond grains but also tungsten carbide wear tips.
For further information, please contact Permabond’s technical team via our inquiries page here.