Study on wear life of high speed cutting tools

Since the 1980s, due to the breakthrough in the design and manufacturing technology of functional components such as spindle and feed system of NC machine tool, the spindle speed and feed speed of NC machine tool have been greatly improved. Driven by the comprehensive progress of modern manufacturing technology, cutting technology has entered a new stage of high-speed cutting. At present, high-speed cutting has been widely used in mold, aviation, automobile and other manufacturing fields, has produced significant economic benefits, and is expanding to other application fields.

High speed machining puts forward a series of new requirements for cutting tools. The research shows that the main causes of tool damage in high-speed cutting are the wear and damage caused by mechanical friction, bonding, chemical wear, edge collapse, crushing and plastic deformation under the action of cutting force and cutting temperature. Therefore, the main performance requirements of high-speed cutting tool materials are heat resistance, wear resistance, chemical stability, thermal shock resistance and coating rupture resistance. Ceramic, CBN, PCD, cermet and other tool materials have good heat resistance and wear resistance. When their toughness is improved, they are very suitable for high-speed cutting. The development of advanced coating technology has further improved the performance of tool materials. At present, the development of new coating materials and coating technology is in the ascendant, which indicates that coated tools will have great development potential and broad application prospects in the field of high-speed cutting.

In this paper, the wear mechanism of ceramic tools, cubic boron nitride tools, diamond tools, cermet tools and coated tools in high-speed machining is comprehensively reviewed, and the wear morphology and wear life of tools are analyzed. These studies will be beneficial to the reasonable selection and wear control of high-speed cutting tools in practical production and processing.

2 wear patterns of high speed cutting tools

In high-speed cutting, the main wear patterns of the tool are flank wear, micro chipping, boundary wear, flake peeling, crater wear on the front flank, plastic deformation and so on.

Flank wear is the most common wear form of high-speed cutting tools, which can be regarded as the normal wear of tools. The increase of the width of the flank wear zone will make the tool lose cutting performance. In high-speed cutting, the VB value of the uniform wear zone width on the flank is often used as the wear limit of the tool.

Micro chipping is a small gap on the cutting edge of the tool, which often occurs in intermittent high-speed cutting. The occurrence probability of micro chipping can be reduced by selecting tool materials with good toughness, reducing feed rate and changing the main deflection angle of the tool to increase stability. Generally, as long as the size of the tool micro chipping edge is controlled within the wear limit, the tool can still continue cutting.