All about CBN cutting tools and their use!
INTRODUCTION
Diamond and cubic boron nitride (CBN) are the two hardest materials used as a cutting tool.Next to diamond CBN is the second hardest substance that can cut all ferrous materials. Diamond is available naturally and another side Carbon-Boron Nitride is man-made. Both the materials can be produced in a laboratory with high pressure and temperature. The demand for higher productivity and low manufacturing cost, thereby imposed development and need for cutting tools capable of operating at high speeds.
CUTTING MECHANISM
High machine speeds produce higher stress and increase the temperature at the workpiece which requires better refractory tool materials. Meanwhile, in cutting hardened steels, irons, super alloys, and metal composites, these tools have a very short span and sometimes becomes unable to cut at all because of the fracture at cutting edge. The materials difficult to cut are mostly shaped by grinding.
ADVANCEMENT
High-pressured cutting technology has made it possible to an evolution of new generation super hard materials on basis of diamond and cubic boron nitride. The tools based on these materials have gradually increased the cutting speeds by century. A CBN tool expected to have adequate fracture toughness to perform under severe machining condition.
PERFORMANCE
The main application of the composite CBN tool is in the machining of hardened steels, irons, hard alloys, and other difficult-to-cut materials.
CVD COATING
Chemical vapor deposition (CVD) is the process in which react and/or decompose on the substrate surface to produce the desired thin film deposit. CVD coating was first used for hard coatings.
CONCLUSION
The CBN tools have an excellent combination of properties such as hardness, inertness and fracture toughness which has been demonstrated that these tools can be used to machine hardened steels, cast irons, titanium alloy economically. These tools can be used for hard-machining of steels in continuous cutting conditions, and hence avoid the grinding operation.
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