What are the decisive factors affecting the performance of diamond grinding wheel
Nov 27, 2021
01
Diamond type
Natural diamond and artificial diamond can be used as diamond abrasive for manufacturing diamond grinding wheel.
02
Diamond grain size
The selection of particle size should be comprehensively considered from the following aspects: first, the processing requirements. The basic principle is to use coarse-grained diamond during rough grinding and fine-grained diamond during fine grinding; The second is the type of bond. The general principle is to select coarse particles for the bond with good bond strength of diamond and fine particles for the bond with poor bond strength of diamond; The third is the grinding efficiency of the grinding wheel. The general principle is that under the condition of meeting the processing requirements and sufficient bond strength, coarse-grained diamond can be selected to improve the grinding efficiency.
03
Bond type
Diamond bonded grinding wheel bond: there are four kinds of bond used for diamond bonded grinding wheel, namely resin bond, ceramic bond, metal bond and electroplated metal bond. The order of their adhesion and wear resistance to diamond is electroplated metal bond > metal bond > ceramic bond > resin bond. The resin binder is mostly made of phenolic resin or polyimide resin as bonding material and metal powder, metal oxide and ordinary abrasive as filler; The main component of ceramic bond is vitrified material with low melting point, such as boron glass, lead glass, etc; According to the types of main metal powders, metal bonds are divided into bronze bonds, nickel or nickel cobalt alloy bonds, WC bonds, cobalt bonds, cast iron bonds, tungsten bonds, silver alloy bonds, etc; Electroplating metal binders mainly include nickel, nickel cobalt alloy, copper, etc.
04
Diamond concentration
Diamond grinding wheel concentration refers to the percentage of diamond volume in the working layer to the total volume of the working layer. Internationally used concentration expression method: the percentage of diamond volume in the working layer to the total volume of the working layer is equal to 25%, that is, the weight of diamond contained in each cubic centimeter volume is 0.88g, which is defined as 100% concentration.
General selection principles of diamond grinding wheel concentration: first, the finer the diamond particle size, the lower the selected concentration. When the workpiece requires fine grinding, low concentration shall be selected. Second, the higher the bonding strength of the binder, the more diamond particles can be firmly bonded, and the higher the selected concentration should be. Third, the grinding wheel with good contour requires high diamond concentration. Such as forming grinding wheel, grinding wheel with wide working surface, grinding groove grinding wheel, etc. Fourth, when the grinding quality requirements are not high, in order to improve the grinding efficiency, a higher concentration can be selected.
05
Diamond hardness
The hardness grade of diamond grinding wheel is divided into super hard, hard, medium hard, medium soft, soft and super soft. Selection principle of grinding wheel hardness:
1. When grinding hard materials, the diamond abrasive grains are easy to blunt, so a soft grinding wheel should be selected to make the diamond abrasive grains fall off in time and sharpen themselves; The opposite is true when grinding soft materials. However, when grinding particularly soft and tough materials, in order to avoid blocking the grinding wheel, a softer grinding wheel should be selected.
2. In case of high grinding temperature and poor cooling conditions, a soft grinding wheel shall be selected to avoid workpiece burns.
3. Under the conditions of grinding intermittent surface and large longitudinal feed, the diamond abrasive particles are subject to large force and easy to fall off, so the grinding wheel with high hardness shall be selected. Fourth, when molding grinding and bus geometry requirements are high, the hardness of the grinding wheel should be properly improved in order to maintain the contour of the grinding wheel.
