1 Introduction Next page Nordic Style Floor,Solid Wood Underfloor Heating,Solid Oak Wood Flooring,Vival Solid Wood Floor TECLIC , https://www.teclicfloors.com
In ultra-precision machining, the main factors to ensure the quality of the machined surface are high-quality tools, in addition to high-precision machine tools and ultra-stable machining environments. Natural diamond has high hardness, good wear resistance, high strength, good thermal conductivity, low friction coefficient with non-ferrous metals, good anti-adhesion and excellent corrosion resistance and chemical stability. It can sharpen sharp edges and be sharpened. It is considered to be the most ideal tool material for ultra-precision cutting, and has an important position in the field of machining, especially in the field of ultra-precision machining.
2 Physical properties of single crystal diamond
Diamond is a crystal of a single carbon atom, and its crystal structure belongs to the equiaxed face-centered cubic system (a system with the highest atom density). Since the bond between carbon atoms in diamond is sp3 hybrid covalent bond, it has strong binding force, stability and directionality. It is the hardest substance known in nature at present, and its microhardness can reach 10000HV. Other physical properties are shown in the table.
Table 1 Physical properties of diamond
Physical properties - numerical hardness -60,000 to 100,000 MPa, bending strength with crystal direction and temperature -210 to 490 MPa
Compressive strength -1500～2500MPa
Elastic modulus - (9 ~ 10.5) × 10 12 power MPa
Thermal conductivity -8.4～16.7J/cm·s·°C
Mass heat capacity -0.156J/(g·°C) (normal temperature)
Start oxidation temperature -900~1000K
Start graphitization temperature -1800K (in inert gas)
Friction coefficient between aluminum alloy and brass -0.05 to 0.07 (at normal temperature)
In the late 1970s, in the research of laser nuclear fusion technology, it was necessary to process a large number of high-precision soft metal mirrors, which required the surface roughness and shape accuracy of soft metals to reach ultra-precision levels. If the traditional grinding and polishing methods are used, not only the processing time is long, the cost is high, the operation is difficult, and the required precision is not easily achieved. Therefore, there is an urgent need to develop new processing methods. Driven by real-world demand, single-crystal diamond ultra-precision cutting technology has been rapidly developed. Due to the physical properties of single crystal diamond, it is not easy to stick to the knife and produce built-up edge when cutting. The surface quality is good. When processing non-ferrous metals, the surface roughness can reach Rz0.1~0.05μm. Diamond can also effectively process non-ferrous metal materials and non-metallic materials, such as non-ferrous metals such as copper and aluminum and their alloys, ceramics, unsintered hard alloys, various fiber and particle reinforced composite materials, plastics, rubber, graphite, glass. And a variety of wear-resistant wood (especially solid wood and plywood, MDF and other composite materials).