Tool is hard, can be used as the time delay, cutting tool also has the certain wear and tear, several reasons that affect the tool wear are what? Through summarizing the several reasons.
1, the cutting tool material
Cutting tool material is the basic factor, decision tool cutting performance for machining efficiency and machining quality, cost and impact on the tool life.
The hard cutting tool material is, the resistance to wear, the better, the higher the hardness, impact toughness is lower, the material is brittle. Hardness and toughness is a pair of contradiction, also is the cutting tool material should be overcome by a key. For graphite tools, common tialn coating can choose the appropriate on select material toughness is relatively better, which is the cobalt content is a little higher; For diamond coating graphite tools, can choose the appropriate on select material hardness is relatively better, which is slightly lower cobalt content;
2, cutting tool geometry angles
Graphite to choose the appropriate tool geometry angles, helps to reduce the vibration of the cutting tool, in turn, graphite artifacts is not easy to collapse lack;
(1) the anterior horn, the graphite processed through negative rake Angle, cutting tool edge strength, impact resistance and friction performance is good, with the decrease of the absolute value of negative rake Angle, the blade surface wear area changed little, but overall showed a trend of decrease, with positive rake Angle processing, along with the rising of the rake Angle, cutting tool edge strength is weakened, cause after the blade surface wear. Processing negative rake Angle, cutting resistance, cutting vibration, increases the using dazheng rake Angle processing, serious tool wear, cutting vibration is bigger also.
Angle after (2), if the Angle increases, the cutter blade intensity is reduced, the blade surface wear area is gradually increased. Cutter, Angle is too large after cutting vibration is strengthened.
(3) the spiral Angle, spiral Angle is small, the same cutting edges and cut into the graphite artifacts the blade length of the longest and largest cutting resistance, cutting tool on cutting force, tool wear, the milling force and cutting vibration is one of the biggest. When the helix Angle is large, the milling force in the direction of the deviation degree on the surface of the workpiece, cutting impact of graphite materials due to its broken intensified, and thus tool wear, the milling force and the cutting vibration is increased. Therefore, cutting tool Angle change on the tool wear, milling force and the influence of cutting vibration is a former Angle, Angle and helix Angle after comprehensive, so in terms of selection must be more careful.
3, tool coating
Diamond coated cutting tools of high hardness, good wear resistance, and low coefficient of friction, diamond coating is the best choice of the graphite processing cutting tool at present stage, also can reflect graphite tools most superior performance; Diamond coating cemented carbide cutting tool is a combination of the advantages of natural diamond's hardness and strength and fracture toughness of cemented carbide; But in the domestic diamond coating technology is still in its infancy, and the cost of investment is very big, so the diamond coating won't have too big development in the near future, but we can in the general tool, on the basis of the optimization tool Angle, material selection, etc and improve structure of ordinary coatings, to some extent, can be in graphite processing of the application.
Diamond coated cutting tools and the common coating tool geometric angles have substaintial distinction, therefore in designing diamond coated tools, due to the particularity of graphite processing, its geometrical angles can be appropriately enlarge, cutting groove is larger, also won't reduce the cutting tool edge abrasion resistance; For ordinary tialn coating, although its abrasion resistance is larger than that of uncoated cutting tool has significantly improved, but compared with diamond coating, in the graphite machining its geometrical angles down should be appropriate, in order to increase its wear resistance.
4, the strengthening of the cutter blade
Cutter blade passivation technology is a still not been paid attention to by people, and again the issue is very important. Blade, diamond grinding wheel grinding of carbide cutting tools after microscopic gaps exist different degree of blade and curf) (that is, the tiny crack. Graphite high-speed cutting processing cutting tool performance and stability is put forward higher requirements, especially the diamond coating tools must pass a knife edge passivation before coating, to guarantee the robustness and the service life of the coating. Tool after passivation is to solve the grinding of cutting tool edge micro gap defect, make the value of its front to reduce or eliminate, achieve smooth level off, sharp, strong and durable.