On the abrasive machining
Sherry Huang
wenku.baidu.com
2015-09-16 17:14:12
Abrasives are used for grinding, lapping and polishing tools. Most of the abrasive with abrasive artificial abrasive plus binding agent made from natural mineral rock is also useful directly processed into natural abrasive. Abrasives except in machinery manufacturing and other metalworking industries are widely used, but also for the processing of food processing, paper industry and the ceramics, glass, stone, plastic, rubber, wood and other non-metallic materials.
Abrasives source of their raw material, natural and artificial abrasive abrasive categories. Commonly used in machinery industry is only natural abrasives Whetstone. Artificial abrasive according to the basic shape and structure of distinction, grinding wheel, grinding head, Whetstone, sand tile (collectively, bonded abrasives) and coated abrasives five. In addition, it is customary to also as a class abrasive grinding tools.
Bonded Abrasives used by abrasive can be divided into ordinary abrasive abrasive and super abrasive abrasive. The former general with corundum and silicon carbide abrasives, which are made of diamond and cubic boron nitride and other superhard abrasive. In addition, there are some special varieties, such as sintered corundum and other abrasive.
Abrasive hardness depends mainly on the amount of binding agent is added to the number and density of abrasive grit off easily, said lower abrasive hardness; on the contrary, represents a high hardness. Hardness grades are generally divided into super-soft, soft, soft, medium, medium-hard, hard and superhard seven level, from these levels may also be subdivided into several smaller stages. The method of measuring the hardness of abrasive, more commonly used hand cone, mechanical cone method, Rockwell hardness measurement method and blasting hardness assay.
Hardness of the dynamic elastic modulus of the abrasive has a corresponding relationship, which is conducive to the determination by the abrasive audio method to represent the dynamic elastic modulus of the abrasive hardness. In grinding, the high if they are grinding the workpiece material hardness, generally used in low hardness abrasive; on the contrary, the selection of high hardness abrasive.
Abrasives crude into tight, medium and loose categories. Each category can be further subdivided and number, with the organization number to distinguish. Abrasives organization number larger share of abrasive abrasive volume percentage of smaller, wider gap between grains, represent more loose tissue. Conversely, the smaller number represents more tightly organized organization. Loose organization of abrasive passivation is not easy when you use less heat in the grinding process, the workpiece can reduce heat deformation and burns. Tight organization of abrasive grains not falling, is conducive to maintaining abrasive geometry. Abrasives organization to be only in the manufacture of abrasive formulation according to control, generally do not make the determination.
Resin bonded abrasives are generally in the press molding at room temperature, there is also heating side pressurized hot pressing process in heating conditions below. After forming in the hardening furnace hardening. When the phenolic resin as binder, curing temperature is 180 ~ 200 ℃.
Rubber bonded abrasives mainly roll-on mixing, and roll into thin slices, then die cutter punching molding; also some with loose materials, put on the inner mold press molding. After the vulcanization molding in the vulcanization tank, a temperature of 165 ~ 180 ℃.
Metal bonded abrasives manufacturing process, there are two powder metallurgy method and a plating method, mainly for superhard abrasive abrasive. Bronze powder metallurgy as the binding agent, or after mixing by hot press molding at room temperature, and then sintering processing. Plating nickel or nickel-cobalt alloy as the plating metal plating process by abrasive consolidated on a substrate made of abrasive.
Special varieties have sintered corundum grinding wheel and other abrasive fibers. Sintered corundum abrasive is alumina powder and an appropriate amount of chromium oxide mixing, forming, sintering at about 1800 ℃. This abrasive compact, with high strength, mainly used for processing watches, instruments and other components. Fiber abrasive is adhered containing or abrasive filaments (such as nylon) as made of raw materials, its good elasticity, mainly used for metal polishing materials and products.
Abrasives source of their raw material, natural and artificial abrasive abrasive categories. Commonly used in machinery industry is only natural abrasives Whetstone. Artificial abrasive according to the basic shape and structure of distinction, grinding wheel, grinding head, Whetstone, sand tile (collectively, bonded abrasives) and coated abrasives five. In addition, it is customary to also as a class abrasive grinding tools.
Bonded Abrasives used by abrasive can be divided into ordinary abrasive abrasive and super abrasive abrasive. The former general with corundum and silicon carbide abrasives, which are made of diamond and cubic boron nitride and other superhard abrasive. In addition, there are some special varieties, such as sintered corundum and other abrasive.
Abrasive hardness depends mainly on the amount of binding agent is added to the number and density of abrasive grit off easily, said lower abrasive hardness; on the contrary, represents a high hardness. Hardness grades are generally divided into super-soft, soft, soft, medium, medium-hard, hard and superhard seven level, from these levels may also be subdivided into several smaller stages. The method of measuring the hardness of abrasive, more commonly used hand cone, mechanical cone method, Rockwell hardness measurement method and blasting hardness assay.
Hardness of the dynamic elastic modulus of the abrasive has a corresponding relationship, which is conducive to the determination by the abrasive audio method to represent the dynamic elastic modulus of the abrasive hardness. In grinding, the high if they are grinding the workpiece material hardness, generally used in low hardness abrasive; on the contrary, the selection of high hardness abrasive.
Abrasives crude into tight, medium and loose categories. Each category can be further subdivided and number, with the organization number to distinguish. Abrasives organization number larger share of abrasive abrasive volume percentage of smaller, wider gap between grains, represent more loose tissue. Conversely, the smaller number represents more tightly organized organization. Loose organization of abrasive passivation is not easy when you use less heat in the grinding process, the workpiece can reduce heat deformation and burns. Tight organization of abrasive grains not falling, is conducive to maintaining abrasive geometry. Abrasives organization to be only in the manufacture of abrasive formulation according to control, generally do not make the determination.
Resin bonded abrasives are generally in the press molding at room temperature, there is also heating side pressurized hot pressing process in heating conditions below. After forming in the hardening furnace hardening. When the phenolic resin as binder, curing temperature is 180 ~ 200 ℃.
Rubber bonded abrasives mainly roll-on mixing, and roll into thin slices, then die cutter punching molding; also some with loose materials, put on the inner mold press molding. After the vulcanization molding in the vulcanization tank, a temperature of 165 ~ 180 ℃.
Metal bonded abrasives manufacturing process, there are two powder metallurgy method and a plating method, mainly for superhard abrasive abrasive. Bronze powder metallurgy as the binding agent, or after mixing by hot press molding at room temperature, and then sintering processing. Plating nickel or nickel-cobalt alloy as the plating metal plating process by abrasive consolidated on a substrate made of abrasive.
Special varieties have sintered corundum grinding wheel and other abrasive fibers. Sintered corundum abrasive is alumina powder and an appropriate amount of chromium oxide mixing, forming, sintering at about 1800 ℃. This abrasive compact, with high strength, mainly used for processing watches, instruments and other components. Fiber abrasive is adhered containing or abrasive filaments (such as nylon) as made of raw materials, its good elasticity, mainly used for metal polishing materials and products.
