Successful trial of synthetic diamond and put into production

First Machinery Ministry research units and factories in the country many research institutes and factories strong support and assistance, self-reliance, a successful trial of  cutting tools  diamond and put into production. Synthetic diamond is an  abrasive grinding  developed in recent years of new products, the production of such products on the technical preparation demanding. Its performance with natural diamond, as is the development of modern industry indispensable thing. Only a few countries in the world to produce the synthetic diamond.

The system energy change occurs in favor of the solid structural changes such electronic

If the energy change in favor of this occurs in the solid changes in the electronic structure, the high temperature phase transition occurs in the solid state, or may occur in the molten state or vapor state. This change occurred in the melt condition that the bonding characteristics of the distribution of the valence  polycrystalline diamond  statistical weight reduction effect tends to disappear remote orderly, coordination number is changed; the electronic excited state statistical weight chemotaxis to increase the role of short-range order corresponding enhancement. This change occurred in the gas condition that elemental interatomic or  abrasive grinding  bonding of the compound of the electron energy levels tend to disappear, all electronic transfers to a single atom or molecule level up, so that the electrons in the excited state is more statistical weight is increased. Accordingly, synthetic diamond can be solid, but also may be in the melt state and the vapor state conditions, depending on the pressure, temperature and component concentration and other factors can cause changes in the system. From the kinetic point of view, but also requires a carbonaceous material such as graphite into diamond with an appropriate transition rate.

Grinding tools, durability comparable unground improve

Practice shows that, after careful grinding tools, unmilled comparable durability increased by 50 percent. Using a cooling lubricant can reduce the temperature of the cutting zone and reduce tool and workpiece, the friction between the tool and the chip, to improve the tool life is advantageous. Experiments show that, with the emulsion  cutting tools  the cutting zone temperature 50 ℃ ~ 100 ℃, with cutting oil can reduce the cutting zone temperature 40 ℃ ~ 60 ℃. Therefore, high-speed steel cutting tool under conditions of heavy load, the multi-use aqueous cooling lubricants, cutting load lighter and requires high precision and surface roughness  abrasive grinding  are much lower with lubricant oil, the tool and lubricating film formed between the workpiece surface, to reduce friction. Carbide good heat resistance, generally without coolant, but in general steel with high-temperature  Polycrystalline diamond  finishing materials, in order to improve the durability of the tool, to ensure accuracy and surface roughness of the workpiece can also be used extreme pressure cutting oil emulsion or cooling lubrication. In summary, our analysis clearly affect the tool life of these factors and the relationship between them, may be based on the specific circumstances of the workpiece material, selection of appropriate materials and cutting tool, select the appropriate tool geometry, quality assurance tool sharpening and cooling lubrication conditions, in order to protect the higher tool life.

The strength of the workpiece material, the higher the hardness, the higher the cutting temperature generated, the faster tool wear

The strength of the workpiece material, the higher the hardness, the higher the cutting temperature generated, the faster tool wear, tool life is lower. Cutting carbon structural steel, carbon steel for tool life have a greater impact. The higher the carbon content, the proportion of cementite and pearlite greater the higher the hardness,  Polycrystalline diamond . Therefore, when the high-carbon steel cutting tool wear faster, lower durability; carbon steel cutting tool wear is relatively slow, durability is relatively high. Further processing of the material elongation of  Diamond blade  thermal conductivity, are to make the cutting temperature, reduced tool life. Tool material impact on tool life tool cutting part of the material affect tool life is a major factor in improving the cutting tool material, the use of high, the more wear and durability is also higher. Quality tool  grinding wheel  and cooling lubrication conditions on tool life of tool sharpening quality durability of the tool has a great influence. Such as cemented carbide cutting tools with silicon carbide grinding wheel, if no fine whetstone grinding, due to the small gap serrated blade, the higher front flank surface roughness and other reasons, the tool wear faster, low durability, and sometimes also easy chipping.

The impact of tool life was "hump-shaped"

Tool geometry parameters on the tool life of:Durability of the rake angle of the tool is clear, and too large, the blade reduces the strength, heat is poor, and easily damaged; if too small and the cutting force and the cutting temperature is increased too much, the durability of both cases are  polycrystalline diamond  rake angle influence on tool life was "hump-shaped", which is the highest peak of the anterior horn durability. Main angle decreases,  Polycrystalline diamond  strength,  Diamond blade  heat dissipation, durability increased. Furthermore appropriately reduced and vice angle increases the tool nose radius can increase strength and improve heat dissipation, so that tool life increased. Tool geometry parameters on the tool life have a more significant impact, is reasonable and advanced tool geometry is one important indicator of whether or not.

Ensure that the tool reasonable method durability

The first method is based on the principle of a single workpiece to develop a minimum durability, called the maximum productivity Durability: The second method is the method  polycrystalline diamond  lowest cost per work step to develop durability principle, known lowest cost Durability: the third method is based on the profit obtained per unit of time to develop maximum durability, called the maximum profit durability.
Analysis shows that the three following  grinding wheel  exists between durability, namely the production of general use of the lowest cost durability, and only when the production task is urgent, or an imbalance in the production of the weak link when it is used in the highest productivity durability.

Tool wear to a certain limit will no longer continue to use

Tool wear to a certain limit will no longer continue to use, the wear limit is called blunt standards.  grinding wheel  Standard ISO uniform regulations after the surface was measured with the wear width VB as a blunt tool wear standard. In actual production, in order to be more convenient, quickly and accurately determine the tool wear, tool life generally is to indirectly reflect the standard blunt tool.
After sharpening the cutting tool from the beginning up until the amount of wear experienced by blunt  Abrasive grinding wheel  total cutting time is called the tool life. Tool life and tool regrinding tool life is the product of the number of times that a new tool into use until retirement from the start until the total cutting time.