Application of the hottest nano diamond

Application of nano diamond

Abstract: nano diamond not only has the inherent excellent properties of diamond, but also has the unique properties of nano materials. It is these comprehensive technical characteristics that enable it to be applied in traditional and new technical fields and achieve initial results. This paper briefly describes the applications of ultra precision polishing, lubrication, composite plating, magnetic recording system and medical treatment, and points out that nano diamond particles have the characteristics of spherical and quasi spherical, which makes the friction surface form ball bearing effect and show good lubricity, So as to avoid the occurrence of friction phenomenon, and for some workpieces that fail mainly due to contact fatigue or high temperature wear, the composite coating of nano diamond metal has obvious advantages

key words: nano diamond; Polishing; Lubrication; Composite plating; Medical treatment

due to the nano scale diamond synthesized by detonation of negative oxygen balanced explosives, it not only has the inherent comprehensive excellent properties of diamond, but also has the unique characteristics of nano materials. Therefore, it has attracted the attention of the majority of engineering and technical experts, especially to explore this kind of phenomenon, which is called the application of submission in different technical fields. In this paper, the progress and achievements of the application of nano diamond in some fields will be summarized. To show its important role and potential bright prospects for the improvement of traditional technology [1]

nano diamond is an industrial diamond with abnormal particle size and shape. The particle size of this kind of diamond is 0 5 ~ 10nm, the average size is about 4 ~ 5nm, and most particle sizes are between 2 ~ 8nm. [2]

it is found that there is a chemical functional group with a wide spectral range on the surface of black powder, which expands the possibility of chemical reaction on its surface, which is conducive to the combination with lubricating oil, polytetrafluoroethylene (PTFE), rubber and other materials

Figure 1 particle size distribution (typical)

Figure 2 approximate range of particle area size

in view of the unique circular particles of nano diamond, it not only has the hardness and wear resistance of diamond, but also has super lubrication performance

therefore, it has been applied in polishing, lubrication, plating and other technical fields, and has achieved initial results

1 ultra precision polishing

polishing is a traditional field of diamond application. Even today, polishing, including ultra precision grinding, is still the most important link in the process of instrument and machinery manufacturing. However, at present, the commonly used abrasive size is greater than 0 one μ M (100nm), nano diamond not only has high hardness, but also the particle size is less than one order of magnitude than the best abrasive, and the carbon surface is easily affected by chemical changes, and can be compatible with any polar medium. This feature makes it possible for nano diamond particles to be evenly distributed in the carrier. Therefore, nano diamond particles are regarded as a new generation of ideal abrasive for ultra-fine polishing, Table 2 lists the polishing results of different hardness and elastic materials

it is worth pointing out that the polishing system containing nano diamond has the following advantages:

(1) ultra-fine nano diamond can ensure the minimum value of surface roughness and the stability of colloid in the polishing system

(2) the chemical stability of nano diamond can be used as active additive of polishing system and reduction of polishing system chemically

(3) reduce the component of polished surface materials and reduce material loss

(4) due to the ion exchange and adsorption activity of nano diamond, the activity of ions and molecular products on its surface can be reduced

(5) the agglomeration structure of nano diamond aggregates is conducive to the regulation of agglomeration in the suspension polishing system, and is non-toxic

(6) the polishing system containing nano diamond can improve the quality and competitiveness of polished products, so as to ensure the machinability of hard to machine materials

2 lubrication

lubrication is closely related to the operation of mechanical equipment. Some people vividly compare lubricating oil to the blood of mechanical equipment. It can be said that without lubrication, there will be no mechanical equipment

efficient and reasonable lubrication technology is the basic measure to ensure and improve the energy-saving, efficient and long-term normal operation of mechanical equipment, the lifeblood of mechanical transportation, and the applied science to serve the national economic development and people's life and welfare. Without efficient and reasonable lubrication technology, there will be no advanced machinery operation, and there will be no advanced production and economic prosperity. Therefore, all industrial countries attach great importance to the research, promotion and application of advanced and reasonable lubrication technology

at present, the effective utilization of mechanical energy in the world is only about 30% on average. According to the calculation of Professor logeffer of Germany, the 1p3 to 1P2 loss of energy production in the world is friction and wear, while Professor Joost of Britain pointed out that 30% - 40% of the world's energy consumption is friction and wear. From the perspective of equipment lubrication, dry friction is harmful. It is mainly manifested in the loss of energy and wear of parts

due to its extremely high hardness, diamond can grind the sharp convex on the friction surface freely and quickly remove the uneven micro peaks on the surface of the friction pair. It belongs to an extremely precise grinding and polishing process, which cannot be achieved by ordinary machining. This effect makes the contact area between friction pairs increase rapidly, accelerates the running in process and improves the running in accuracy. The spherical and quasi spherical particles of nano diamond are embedded in the contact micro concave between the friction pairs. With excellent bearing capacity, the friction surface forms a ball bearing effect, showing good lubricity, turning sliding friction into rolling friction, reducing the friction resistance, and avoiding the occurrence of dry grinding. Here, two examples are introduced to illustrate the important role of nano diamond in lubrication

example 1. The research of Daniel kamman and Vitaly Komarov shows that the use of core and shell diamond conforms to the traditional lubricating fluid, which can reduce the wear, friction coefficient and friction temperature, and improve the load and service life of equipment components [3]

example 2. The biggest difference with other engine oil additives is that they can take immediate effect and have good durability. After adding, the sound of the engine immediately becomes quiet, and the sound of old machines and diesel engines changes more obviously. The durability of the added engine oil was tested according to the lubricant evaluation method of American military specification (MTL). The results show that it is obviously different from the traditional lubricants such as molybdenum disulfide system, organic molybdenum system and fluorine resin, as shown in Figure 3, figure 4 and figure 5

Fig. 3 durability time of various additives under 1000 pounds load (Falex experiment)

3 composite plating of nano diamond [4 ~ 9]

the compounding of materials is an inevitable trend of material development. With the development of modern industry, mechanical parts need to work under complex and engraved conditions and environments, which puts forward higher and higher requirements for material surface properties. As an effective surface modification measure, surface coating technology came into being and has been widely used

however, for some cylinder blocks, piston rings, molds, crankshafts, bearings, etc. that fail mainly due to contact fatigue or high-temperature wear, a single coating is difficult to meet the requirements. The research shows that the composite coating can effectively improve the bonding strength between the coating and the substrate, improve the distribution of internal stress and the direction of crack propagation, and obtain some special and excellent properties. Therefore, composite coating has become one of the research hotspots in the field of surface engineering

however, the solid particles (diamond, silicon carbide, etc.) in the composite electrodeposition film are in the order of millimeter and micron. The finer the solid particles in the plating solution, the better the dispersion of particles in the composite coating, and the more obvious the strengthening effect of the coating. Therefore, nano diamond has advantages. Because it not only has the superhard, high anti-wear, heat-resistant and anti-corrosion properties of diamond, but also has rich hydroxyl, carboxyl, carbonyl and other functional groups on the surface of particles. It has a strong binding force with the plated surface, with small dosage and significantly improved performance. It is very suitable for composite plating, which can be used not only on metal surfaces, but also on rubber, plastic, glass and other surfaces

it is understood that the annual metal corrosion loss in the world is about 150billion US dollars. China's annual loss is 150billion yuan, and metal plating is one of the ways to solve it. There are more than 15000 electrolytic electroplating plants in China, but the technology is the same, the level is low, the bonding strength between wear-resistant corrosion degree and substrate is poor, and the pollution is large. It is a traditional industry that needs to be upgraded urgently

in recent years, foreign nano diamond composite coating additives have been used, which have obvious effects but are expensive. Our nano diamond electrolytic plating film additives have strong affinity with the substrate, and their wear resistance is superior to foreign products. The selling price is only 60% of that of foreign countries, and now it has begun to replace imports. We have made a rough estimate. For example, the electrolytic plating surface reaches 300million square meters every year, and the plating thickness is 5 μ M calculation, 1 g of nano diamond lime powder is required per square meter, and a total of 30000 tons of nano diamond composite coating additives are required, equivalent to 600000 kg of nano diamond

at present, China has an annual output of 2billion, which will reach 3billion in 2005. It is mainly supported by automobiles, motorcycles, household appliances, mining machinery, textile machinery, shipbuilding and precision machine tools and instruments, military industry and exports. It is in urgent need of nano composite electroplating process upgrading

there is a huge market for die plating and decorative plating of plastic and glass in China. Before nano diamond composite plating, just close the oil delivery valve

nano diamond metal composite plating has the following commonalities; High wear resistance and microhardness; High corrosion resistance and small porosity; Very low friction coefficient; High cohesion and adhesion; Electrolyte has high diffusion ability, so it has attracted great interest and attention of engineering and technical experts. The application of nano diamond metal composite plating will lead to the innovation of electrochemistry and electroless plating technology

4 nano diamond is used in magnetic recording system

first, nano diamond is used as an additive for wear reduction and a physical denaturant in ferromagnetic coating of magnetic tape and disk; Secondly, the stability of magnetic recording can be improved by adding its additive to the electrochemical composite film [10 - 12]

(1) nano diamond additives into the ferromagnetic layer significantly reduce the magnetic domain (ferromagnetic particles), that is, the recording density increases significantly

when nano diamond is introduced into the clean special film of the magnetic head, its wear resistance is significantly increased

the soft magnetic information carrier containing nano diamond has the following advantages: the wear of the magnetic carrier layer is reduced, the best working conditions of the magnetic head and reading can be ensured, the friction of the magnetic carrier is reduced, and the operation stability is improved

(2) compared with pure cop film, the amorphous film of cop nano diamond soft magnetic shows that the microhardness increases by 30%; If there is a large difference between the actual humidity and the target humidity, the wear resistance is improved by 3 5 times, the friction coefficient decreases by 28 6%, and the service life of the magnetic head iron core is doubled

compared with pure electrochemical or electroless plating cop coating, the microhardness of hard magnetic polycrystal of cop nano diamond is increased by 20%, and the corrosion current is reduced by 37 5%, the service life of magnetic recording carrier increases

when nano diamond is added, the magnetic properties of both soft magnetic amorphous and hard magnetic coatings do not change

when the layer thickness is 1 M, the unit consumption of nano diamond is 1m2, about 1 carat

5 nano diamond for medical treatment

nano diamond has exceptionally high adsorption capacity, large specific surface area, and a large amount of freedom on the surface