Effect of workpiece and tool conditions on tool wear in woodworking
- The effect of the nature of the workpiece being cut
Density is one of the basic physical and mechanical properties of wood and has little effect on cutting tool wear. For the material itself to be cut, the processing properties that must be considered are as follows: wood moisture content, silicon oxide or silicate content, extract composition and content. Generally, the cutting resistance of air-dry wood is greater than that of raw wood, but when cutting non-silicon tree species, the wear of raw wood cutting tools is larger. On the other hand, when cutting tools made of tool steel materials that do not contain silicon trees, the wear amount of cutting gas dry wood tools is larger, it can be seen that the presence or absence of silicon substances makes the results of tool wear completely opposite, but if carbide is used, silicon substances will have no effect on the amount of tool wear. The PH value of the water extract of the wood is mostly less than 7, which is acidic, which is also the reason why the raw material causes more wear to the tool than the air dry material, especially in the PH value of less than 4 occasions, its tendency is more obvious. Other extractive components that can chelate with the tool material can also increase tool wear. This kind of corrosion wear is more effective in corrosion engineering with cathodic corrosion prevention method, the tool side is the cathode, the workpiece side is the anode, and the direct current of a certain voltage is added between the two for cutting processing, and the corrosion is suppressed when the voltage is increased, so that the wear amount is reduced. Adhesives and fillers used in wood materials, as well as foreign objects such as tiny sand particles mixed into wood composites during processing and manufacturing can also cause or exacerbate tool wear
- The effect of tool conditions
Under normal circumstances, the greater the hardness of the tool material, the smaller the tool wear, compared with alloy tool steel, the wear of high-speed steel is small, and the wear of cemented carbide is smaller. However, there are also cases that do not conform to this law, such as cemented carbide, not necessarily because of high hardness, bending strength is not high, the amount of wear must be small. If the tungsten carbide particle diameter in the cemented carbide becomes smaller, the content of metal cobalt increases, the hardness and bending strength of the material are increased, and the amount of wear and stripping is also increased. The relationship between hardness and wear is also reversed in tool steels. Such as the tool material containing large particles of carbide, its overall hardness is relatively small, the wear amount is also very small. So hardness and wear is not a simple linear relationship.
The physical properties that affect the amount of tool wear include thermal conductivity, specific heat, coefficient of thermal expansion, Angle of cutting edge, etc. In addition to the research and improvement of the tool material, in order to make the tool toughness at the same time as the surface hardness is relatively high, the tool can also be coated with coating treatment, the surface of the wood cutting tool, especially the hard metal material coated with chromium after the knife surface, the tool is only worn in the front knife surface, which can slow down the passivation of the knife edge.
There are many other factors that affect tool wear, and we SHJ have been committed to providing more professional solutions.
