Introduction of Basic Knowledge and Varieties of Ceramic Grinding Wheel

1. Material selection of ceramic grinding wheel
Ceramic grinding wheels use more types of abrasive materials, each suitable for different cutting and grinding. Specifically, brown corundum (A) is suitable for grinding carbon steel, cast iron alloy steel, hard bronze, etc. White corundum (WA) is suitable for grinding hardened steel, alloy steel, high speed steel, tool steel, etc. Black silicon carbide (C) is suitable for grinding non-ferrous metals, rubber, leather, plastics, etc. Green silicon carbide (GC) is suitable for grinding hard alloy, optical glass, ceramic materials, etc. SG and CBN ceramic abrasives are widely used in difficult to grinders.
In addition, in order to give full play to the advantages of various abrasives in grinding, mixed abrasives have been widely used in the manufacture of abrasive tools to improve the grinding efficiency of abrasive tools. For example, when grinding ductile iron, A/WA mixed abrasives are generally used.
2. Grinding tool granularity selection principle
When selecting the abrasive particle size, it is mainly selected according to the requirements of processing accuracy, surface roughness and grinding efficiency. The general principles are as follows:
(1) It is required that the roughness of the ground workpiece is high, and the coarse grain size should be selected; the surface roughness is required to be low, and the fine grain size should be selected.
(2) When the workpiece requires higher geometric accuracy and lower surface roughness, the mixed particle size should be selected.
(3) The geometric accuracy of the workpiece is required to be high. When the contact area between the grinding wheel and the workpiece is small, the fine grain size is selected; when the contact area is large, the coarse grain size is selected.
(4) The workpiece material is hard and brittle, and fine granularity should be selected; the workpiece material is soft and tough, and coarse granularity should be selected.
(5) The thermal conductivity of the workpiece is poor, easy to heat deformation, easy to burn, should choose a coarser granularity.
3, Abrasives hardness selection principle
When selecting the hardness of the abrasive tool, it is mainly selected according to the nature of the workpiece material and the grinding method. The general principles are as follows:
(1) When grinding hard materials, abrasive particles are easy to blunt. In order to make the blunt abrasive particles fall off in time, softer abrasives should be selected.
(2) When grinding soft materials, abrasive grains are not easy to blunt. In order not to make the unblunt particles fall off prematurely, harder abrasives should be used.
(3) When grinding very soft and tough non-ferrous metal materials, in order to avoid the grinding tool being blocked, a softer grinding tool should be selected.
(4) If the linear speed of the grinding wheel is low, a harder grinding wheel should be selected; if the linear speed of the grinding wheel is high, a softer grinding wheel should be selected. The contact area between the grinding wheel and the workpiece is large, and a softer grinding wheel should be selected; the contact area is small, and a harder grinding wheel should be selected.
(5) When grinding workpieces with poor thermal conductivity, easy deformation and burn, a softer grinding wheel should be selected.
(6) dry grinding, in order to reduce the heat, to avoid workpiece burn, should be wet grinding when the hardness of soft 1-2 small grade.
(7) When the grinding effect is required, a softer grinding wheel can be selected.
(8) When the roughness requirement is low, a harder grinding wheel can be selected.
4. Selection principle of grinding tool organization
The organization selection should be selected according to the grinding method, the nature of the workpiece material, the machining allowance, the contact surface size of the grinding tool and the workpiece. The general principles are as follows:
(1) general cylindrical grinding, internal circular grinding, no center grinding, tool grinding or grinding wheel circular grinding plane, etc., choose medium organization.
(2) grinding soft and tough metal, choose loose organization; grinding hard and brittle metal, should choose a more compact organization.
(3) large contact area, should choose loose organization; contact area is small, should choose tight organization.
(4) grinding leather and other low hardness and toughness of the material and sheet easy to burn deformation of the workpiece, can choose loose tissue grinding wheel.
(5) The grinding allowance is large, and the looser organization is selected; the grinding allowance is small, and the tighter organization is selected.
5. Ceramic grinding wheel applications
Ceramic bond is the most widely used, in the grinding process of good shape retention, practical in rough grinding (such as inner circle, outer circle, plane grinding, etc.), molding grinding (such as grinding thread, grinding gear, etc.), grinding crankshaft and a variety of cutting edge grinding. In addition, large pore grinding wheels can be made with ceramic bonds for grinding rubber, plastics and other materials with low hardness and high toughness.