The Diamonds In most cases the diamonds are synthetically manufactured to specific shapes, depending on what material they are to cut, though some segments can contain a mix of synthetic and real. Synthetic diamonds have exactly the same degree of hardness as natural diamonds but, whereas natural diamonds vary in structure, synthetic ones can be manufactured to optimum structures that remain consistent. They can also be adjusted in grain size and crystalline shape to suit the cutting of specific materials and thereby optimise the life of the blade. Blade life is not solely dependent on how many diamonds are present, but rather on a balance between diamond concentration and bond composition, in relation to the material to be cut. There are three different methods of joining the segments to the blank: Sintering - This fuses the bond metals, with heat and high pressure, onto the blank. Cheaper blades use this process. Laser welding - Used for high quality blades where the join is permanent. Any segment-loss is almost always caused by user error. Soldering - On large diameter wet cutting discs, the segments are brazed to the blank using silver solder. Because a wet blade will be working with cooling water, it will not require its segments to be joined at high temperature.
Bond Materials to be cut will rank somewhere on a scale from hard & dense to soft & abrasive; this is known as the ‘MOHS’ scale. When the material is hard, such as glass, the diamond grain will wear down or break. Therefore, it is necessary for the bond to be soft allowing it, and the diamond grain, to wear away evenly. When the material is soft, such as asphalt, the diamond grain will remain in good condition. However, the bond will need to be hard to withstand wear from the abrasive large particles found in asphalt and other soft materials. A blade designed for cutting granite, but used on asphalt, would suffer rapid bond wear and consequential loss of unworn diamonds. An asphalt blade used to cut granite would result in rapid diamond loss on the surface of the segment but with the bond remaining intact, resulting in no cutting action. The perfect wear is when diamond grain is released evenly, exposing new diamond and where the bond trails behind each diamond like a comet tail, giving it support and optimum cutting. Blank The core is made from heat treated high alloy steel and balanced to withstand the stress of rotating up to 7,950m/sec (for a 300mm blade) without warping. Blanks can be made in various designs to bring consistent perfection to the cut.
Where the finished appearance of the cut is important, such
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