Topic 4: Controlled crystallization of amorphous materials (4:00)

Plan of the lecture

1. Areas of production of bulk nanostructured materials.

2. Controlled crystallization of amorphous materials.

Currently, there are three areas of production of bulk nanostructured materials: a controlled crystallization of amorphous materials, compaction of ultrafine powders and severe plastic deformation of materials with conventional grain size.

When using controlled crystallization of amorphous materials the transition from the amorphous material in micro-and nanocrystalline state is in the process of sintering of amorphous powders, as well as hot or warm pressing or extrusion. The size of the crystals, resulting in an amorphous material, control the temperature of the process. Method is promising for the materials for various applications (magnetic, heat-resistant, wear-resistant, corrosion-resistant, and so on), and on a variety of bases (iron, nickel, cobalt, aluminum). The disadvantage is that the receipt of the nanocrystalline state are less likely than microcrystalline.

Recommended Reading

1. New materials / VN Antsiferov, FF Bezdudny, LN Belyanchikov and others, ed. YS Karabasova, Ministry of Education of the Russian Federation. - Moscow: MISA, 2002. - 736 p.

2. New substances, materials and products made of them as objects of inventions: Directory / VI Blinnikov etc. - Moscow, Metallurgy, 1991. - 262 p.

3. Rzhevskaya SV Materials science. - M. Bauman, 2000. - 280.

4. Kulikov V.Yu. Textbook for the course "New Materials", KSTU, 2006.

5. Morokhov ID, Cowards DD, Lapovok VI Physical phenomena in ultra environments. - Moscow: Nauka, 1984.

6. Gusev AI Nanocrystalline materials: preparation methods and properties. - Ekaterinburg, 1998.

Control tasks for independent work of the student (theme 4) [1, 2, 3, 7]

1. The use of controlled crystallization of amorphous materials for wear resistant steels.

2. The use of controlled crystallization of amorphous materials for high-temperature steels.

3. The use of controlled crystallization of amorphous materials for magnetic steel.

Topic 5 Compaction of ultrafine powders (4:00)

Plan of the lecture

1. Compacting ultra Proshko.

2. Scheme for producing bulk nanomaterials by evaporation, condensation and compaction.

3. Hot extrusion method.

4. By hot pressing.

The second direction associated with the compaction of UDP, developing in several variants. In the first case, the method of evaporation and condensation of atoms to form nanoclusters - particles deposited on the cold surface of a rotating cylinder in the rarefied atmosphere of an inert gas, usually helium (Figure 1.1).

1 - a rotating cylinder, cooled by liquid nitrogen, 2 - scraper, 3 - an inert gas (usually not), 4 - Evaporator 5 - valve, 6 - fixing the mold 7 - slide 8 - piston 9 - sleeve, 10 - site of the final compaction at high pressure, 11 - unit prior compaction