Powder is widely used in our daily life and industrial and agricultural production. For example, flour, cement, plastics, paper, rubber, ceramics, pharmaceuticals, etc., the following are some important applications that simply describe powder:

First, in the ceramic material industry:
The traditional ceramic preparation process is as follows： 
    The mineral raw material → ceramic powder → uniformly mixed according to the ratio → forming the billet → sintering → obtaining the finished ceramic product。
1、Excellent performance of ceramic materials: Compared with metal: it has high temperature resistance, corrosion resistance, wear resistance and high hardness; it has some characteristics in sound, light, electricity, magnetism and heat.
2、Achilles heel of ceramic materials：
    Brittle: no significant deformation, brittle fracture. Improving brittleness is the goal pursued by ceramics scholars and is an eternal topic。
    Difficult to process: It is extremely hard and can be used as a tool material. Who can process it？
    Difficult to sinter: The melting point of ceramic materials is generally high, and the sintering temperature is related to the melting point, so the sintering temperature is also high.
3, the advantages of nano-powder: it is possible to toughen ceramics with nano-powder, which can be processed to reduce the sintering temperature.
二、Application of powder technology in metallurgical industry：
1. Metallurgical technology: The iron and steel smelting process must go through the following processes: mining iron ore → broken iron ore → beneficiation to obtain iron fine powder (about 63% iron) → sintering into pellets → such as blast furnace smelting → get pig iron。
Among them: crushing and beneficiation and pelletizing sintering involve the field of split engineering. Some alloy fillers are powder。
2、Powder metallurgy：
All kinds of raw materials are powders, which are mixed and sintered to form metal or alloy workpieces without mechanical processing, high production efficiency and small degeneration。
3、Cemented carbide: For example, W-Co cemented carbide, because of the high melting point of W, it is difficult to obtain parts by smelting method. Usually, the chemical element is used to obtain the elemental material. The alloy tool can be manufactured by powder metallurgy.
 Third, the catalyst
1. Superfine powder advantage:
     The particles are fine and much larger than the surface. The proportion of the number of surface atoms increases, the number of unsaturated bonds increases, and the surface activity is high.
2, suitable as a catalyst material: using nano-scale powder as a catalyst can greatly improve the reaction rate and efficiency
3. Example: Using nano-nickel as a rocket solid fuel reaction catalyst, the combustion efficiency can be increased by 100 times. A catalyst made of nickel and a copper-zinc alloy as a main component can increase the efficiency of hydrogenation of organic matter by more than 10 times that of a conventional nickel catalyst. The use of nano-scale powder can be increased to 100 times.

 Fourth, the coating material
     Adding a new layer of material to the metal surface will bring new properties to the material.
1, the composition of the coating
Metal and alloy ultrafine powder coating materials: some elements are based, such as nickel, chromium, copper, iron. Then, a layer is formed to form an ultrafine powder alloy powder such as aluminum, carbon, boron, silicon or the like.
2. Thermal barrier coating (TBC: Thermal Barred Coating)
The inorganic non-metallic material forms a composite coating with the ceramic ultrafine powder. Considering the high melting point of the ceramic material, a transitional material is added between the coating and the base metal to ensure a firm bond. Currently, U.S. Air Force aircraft turbine engine blades are coated with TBC material.
3, stealth material coating
The surface of the US F117 stealth aircraft is coated with stealth coating material, the so-called stealth aircraft.
 Stealth coating material composition: coating with nano-scale powder, the surface of the aircraft is covered with a layer of infrared and microwave stealth materials. It has excellent broadband microwave absorption and can escape radar monitoring.
4, the principle of invisibility:
 One of the principles:
 There are a variety of nanoparticles in stealth materials that are smaller than infrared and radar wavelengths. Therefore, the transmittance of the nanoparticles to these two waves is much stronger than that of the conventional materials, the reflectance is reduced, and the signal received by the detector is weak.
 The second principle:
    The specific surface area of the nanoparticles is large, 2-4 orders of magnitude larger than that of the general material, and the absorption rate for infrared and radar waves is larger than that of conventional materials, resulting in a decrease in reflectance and a weak signal received by the detector.