Huajing micro drill: a new field of application of nanodiamond

Due to the use of negative oxygen balance explosives to synthesize the obtained nanometer-scale diamond, not only has the comprehensive excellent properties inherent in diamond, but also has the singular characteristics of nanomaterials. Therefore, it is concerned by the majority of engineering and technical experts, especially its application in different technical fields. This article will provide an overview of the progress and effectiveness of nanodiamond applications in some areas. To demonstrate its important role and potential prospects for the improvement of traditional technology.

Nano-diamond is an industrial diamond with abnormal particle size and shape. The particle size of such diamond is between 0.5 and 10 nm, the average size is about 4 to 5 nm, and most of the particles are between 2 and 8 nm.

In view of the unique round particles of nano-diamond, it not only has the hardness and wear resistance of diamond, but also has super-lubricating properties.

Therefore, it has been applied in the fields of polishing, lubrication, plating, etc., and has achieved initial success.

1, super fine polishing

Polishing is a traditional field of diamond applications, and even today, polishing, including superfinishing, is still one of the most important aspects of instrumentation and mechanical manufacturing processes. However, the commonly used abrasive sizes are greater than 0.1 μm (100 nm), and the nano-diamond is not only high in hardness, but also has a particle size smaller than an order of magnitude than the best abrasive, and the carbon surface is highly susceptible to chemical change, and Compatible with any polar medium, this feature makes it possible for nanodiamond particles to be evenly distributed in the carrier. Therefore, nanodiamond particles are regarded as a new generation of ideal abrasives for ultra-fine polishing. It is worth noting that the polishing system containing nanodiamonds has The following advantages:

(1) Ultra-fine size nanodiamonds ensure minimum surface roughness and stability of the polishing system colloid;

(2) The chemical stability of nanodiamonds, which can be chemically used for the reduction of active additives and polishing systems in polishing systems;

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

(4) Due to the ion exchange and adsorption activities of nanodiamonds, the activity of ions and molecular products on the surface thereof can be reduced;

(5) The agglomerate structure of the nano-diamond agglomerates is advantageous for the regulation of coalescence in the suspension polishing system and is non-toxic;

(6) Polishing system containing nano-diamond can improve the quality and competition of polishing products to ensure the processing of difficult-to-machine materials.

2, lubrication

Lubrication is closely related to the operation of mechanical equipment. Some people visually compare the lubricating oil to the blood of mechanical equipment. It can be said that if lubrication is lost, there is no mechanical equipment.

Efficient and reasonable lubrication technology is the basic measure to ensure and improve the energy-saving, high-efficiency and long-term normal operation of mechanical equipment. It is the lifeblood of mechanical transportation and the application science for the development of national economy and people's welfare. Without efficient and reasonable lubrication technology, there is no advanced mechanical operation, and there is no possibility of advanced production and economic prosperity. Therefore, all industrial countries attach great importance to the research and popularization 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 calculations of Professor Roggeur of Germany, the loss of 1P3 to 1P2 in the world's energy production is in friction and wear, while Professor Gonster of the United Kingdom points out that the world consumes 30 energy. % to 40% is consumed in friction loss, and dry friction is harmful from the viewpoint of equipment lubrication. Mainly manifested in the loss of energy and the wear and tear of the parts.

Due to the extremely high hardness of diamond, the free grinding of the sharp surface on the friction surface and the rapid removal of the uneven peaks on the surface of the friction pair are extremely precise grinding and polishing processes, which cannot be achieved by ordinary machining. This action causes the contact area between the friction pairs to increase rapidly, speeding up the running-in process and improving the running-in precision. The spherical and quasi-spherical particles of the nanodiamond are embedded in the contact dimples between the friction pairs. It has excellent bearing capacity, the friction surface forms a ball bearing effect, exhibits good lubricity, turns sliding friction into rolling friction, and reduces frictional resistance, avoiding the occurrence of dry grinding. Two examples are presented here to illustrate the important role that nanodiamonds play in lubrication.

Studies by Daniel Kamman and Vitaly Komarov show that the use of core and shell diamonds conforms to traditional lubricants, reducing wear, friction and friction temperatures, and increasing the load and service life of equipment components.

The biggest difference with other oil additives is that it can be immediately effective and has good durability. After the addition, the sound of the engine will be quiet immediately, and the sound changes of the old machine and the diesel engine will be more obvious. The durability of the oil after the addition was tested in accordance with the US Army Standard (MTL) lubricant evaluation method. The results show that there are significant differences compared to conventional lubricants such as molybdenum disulfide, organic molybdenum, and fluororesin.

3. Composite plating of nano diamond

The composite 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, and higher and higher requirements are put on the surface properties of materials. As an effective surface modification measure, surface coating technology has emerged and is widely used.

However, for some cylinders, piston rings, molds, crankshafts, bearings, etc., which are mainly due to contact fatigue or high temperature wear, a single coating has been difficult to meet. Studies have shown that the composite coating can effectively improve the bonding strength between the coating and the substrate, improve the distribution of stress in the coating and the direction of crack propagation, and obtain some special and excellent properties. Therefore, composite coatings have become one of the research hotspots in the field of surface engineering.

However, the solid particles (diamond, silicon carbide, etc.) in the composite plating film are both in the millimeter and micron order, and the finer the solid particles in the plating solution, the better the dispersibility of the particles in the composite plating layer, and the more obvious the strengthening effect of the plating layer. Therefore, nanodiamonds have advantages. Because it not only has the super hard, high anti-wear, heat and anti-corrosion properties of diamond, but also has rich functional groups such as hydroxyl, carboxyl and carbonyl on the surface of the particles, which has strong binding force with the plated surface, the dosage is small, and the performance is improved significantly. It is very suitable for composite plating, not only for metal surfaces, but also for the coating of rubber, plastic, glass and other surfaces.

It is understood that the annual metal corrosion loss in the world is about 150 billion US dollars. China's annual loss is 150 billion yuan, and metal plating is one of the solutions. China's electrolytic plating industry has reached more than 15,000, but the technology is similar, the level is low, the combination of wear-resistant corrosion degree and substrate is poor, and the pollution is large, which is a traditional industry that needs to be upgraded.

In recent years, the use of foreign nano-diamond composite plating film additives has begun to be effective, but it is expensive. Our nano-diamond electrolytic plating film additive has strong affinity with the substrate and its wear resistance is superior to that of foreign products. The price is only 60% of the foreign price, and has begun to replace the import. We have made a rough estimate. For example, the surface of electrolytic plating reaches 300 million square meters per year, the thickness of the plating layer is calculated as 5μm, and the nano diamond powder is required per square. 1 gram, a total of 30,000 tons of nano-diamond composite coating additive is required, equivalent to 600,000 kilograms of nano-diamond.

China's current annual output of 2 billion, will reach 3 billion in 2005, mainly supporting automobiles, motorcycles, home appliances, mining machinery, textile machinery, shipbuilding and precision machine tools, military and export, and urgently need nano-composite plating process upgrade.

The market for mold plating and plastic and glass decorative plating in China is huge, and the prospect of nano-diamond composite plating is broad.

Nano-diamond metal composite plating has the following properties: high wear resistance and microhardness; high corrosion resistance and small porosity; very low friction coefficient; high cohesion and adhesion; The ability to spread, therefore, has caused great interest and concern from engineering and technical experts. The application of nano-diamond metal composite plating will lead to innovations in electrochemical and electroless plating techniques.

4 nano diamond for magnetic recording system

First, nano-diamonds are used as anti-wear additives and physical denaturants in ferromagnetic coatings on magnetic tapes and magnetic disks. Secondly, the stability of magnetic recording can be improved by electrochemically compounding the additives.

(1) The nanodiamond additive significantly reduces magnetic domains (particles of ferromagnetics) into the ferromagnetic layer, that is, the recording density is significantly increased.

The nano-diamond is introduced into a special film in which the magnetic head is cleaned, and the wear resistance thereof is remarkably increased.

The soft magnetic information carrier containing nanodiamond has the following advantages: the wear of the magnetic carrier layer is reduced, the optimum working condition of the magnetic head and the reading is ensured, the friction of the magnetic carrier is reduced, and the running stability is improved.

(2) Compared with the pure CoP film, the amorphous film of the CoP nanodiamond soft magnetic film shows a microhardness increase of 30%; the wear resistance is increased by 3.5 times, the friction coefficient is reduced by 28.6%, and the magnetic core of the magnetic head The service life is increased by a factor of two.

Compared with the pure electrochemical or electroless CoP coating, the microhardness of the hard magnetic polycrystal of CoP nanodiamond is increased by 20%, the corrosion current is reduced by 37.5%, and the service life of the magnetic recording carrier is increased.

When the nanodiamond is added, the magnetic properties of the soft magnetic amorphous layer or the hard magnetic plating layer are not changed.

5, nano diamond for medical treatment

Abnormally high adsorption capacity of nanodiamonds, large specific surface area, large number of free electrons on the surface (a large number of atomic donors), nanometer size, a large number of oxygen-containing functional groups on the surface of the crystal, chemical inertness of the particles, hydrophilicity of the surface Characteristics are important for the agents that may be used for treatment.

Nanodiamonds can be applied to oncology, gastroenterology, cardiology, vascular disease diagnosis and treatment, etc. They are not carcinogenic or mutagenic, and are not toxic.

Nanodiamonds show very high activity against pathogenic viruses, microorganisms and bacteria, and they are strongly absorbed due to their high adsorption capacity and other unique properties. They are superactive adsorbents. Biologically reducing the mobility of active substances is a means of sharply strengthening the action of pharmaceutical agents, and the application of nanodiamonds induces the normalization of blood pressure. In addition, when the gastrointestinal system is sick, nanodiamond is effective and is the best means to prevent burns, different skin diseases, and visceral poisoning.

Nano-diamond is applied to aqueous and oily suspensions, which is beneficial to the strengthening of tumor medicinal reagents, as well as reducing and eliminating painful effects, normalizing intestinal peristalsis, improving blood parameters, and improving the activity of life and immune systems. Discharge from the body and so on.

The combination of nanodiamonds with chemical and radiotherapy shows great promise. Malignant neoplasms are used to prevent mutagenicity of therapeutic agents, and nanodiamonds do not reduce their efficacy, as well as prevent the occurrence of mutations in normal cells and secondary tumors under the action of cancer drugs.

A nanometer diamond of about 0.02 to 0.05 g is required for a course of treatment.

6, nano-diamond has thousands of times higher conductivity than copper , can be made into OLED panel, battery shielding coating, anti-corrosion coating, its conductivity, toughness can be used in semiconductor, photovoltaic, battery, display field, can also do It can be used as a medical device (diamond tooth, human blood vessel, etc.) as a sensor, as a charged contact, for seawater desalination, for mobile equipment, energy production and storage, and its battery storage capacity is 10,000 times that of lithium batteries;

7. Application of nanodiamonds on renewable resources : Through a device called a thermionic energy converter, various solar, geothermal and nuclear energy resources are converted into electrical energy. Through the combination with plasma nanostructures, the superior properties of the diamond in the thermionic converter are maximized, thereby maximizing the absorption of solar energy and ultimately converting it into electrical energy.

The beta radiation produced by carbon 14 (C14) in radioactive graphite improves the performance of the thermionic diamond energy converter. If C14 in the energy converter can be fully utilized, it will provide a more economical method for the treatment of radioactive graphite in retired nuclear reactors. These materials can be used as a raw material for a new type of thermionic energy converter, called the "β-enhanced thermionic diamond converter" (BTDC).

8. Application of nanodiamonds in photoluminescence : Researchers at the University of Rochester in the United States first measured the beam emitted by photoluminescence on suspended nanodiamonds in free space; this experiment used lasers to hold nanodiamonds in the air. Then, the diamond is irradiated with another laser beam to emit light in a fixed frequency form.

This nanostructured optomechanical resonator can be used in high-sensitivity sensors to measure small displacements of metal plates and mirrors in microchip devices and to help people understand friction from nanometer concepts.

9. Nano-diamonds for research and development

A new diamond sensor capable of working in very extreme environments, such as deep gas and oil drilling or space development; new diamond laser media for industrial and medical laser applications and next-generation diamond-coated organisms Medical implants are twice the life of existing grafts.

The research team at Harvard University has made another gratifying step in the field of quantum technology by developing nano-diamond wire equipment.

The new device provides a stable, bright single photon source at room temperature; one of the fundamental elements for safe and fast calculations in optical applications.

The research results have brought the application of nanostructured diamond equipment to quantum communication and computing to a new level, and it is expected to play a significant role in biochemical sensing and scientific imaging.

Nano-diamond wires provide a more natural and efficient interface solution for exploring individual color centers; this device brightens the color center and enhances the sensitivity of the color center. The resulting enhanced optical properties greatly enhance the efficiency of photon collection compared to natural diamond devices.

In the research of nano-diamonds for more than 40 years, the research of nano-diamonds has gone all the way to the present, from the immature to the present, the role of nano-diamonds is getting bigger and bigger, and the development of science and technology will also be immeasurable. The role.