1. The past, present and future of metal materials
Phase 1 - Raw Steel Production
4300 BC: Natural gold, copper and forging crafts
2800 BC: Iron smelting
2000 BC: Prosperity of bronze wares, chimes and weapons (Shang, Zhou, Spring and Autumn and Warring States)
Eastern Han Dynasty: repeated forging steel → the most primitive deformation heat treatment process.
Quenching technology: "Bath with the drowning of five animals, quench with the fat of five animals" (modern water quenching, oil quenching).
King Fuchai of Wu and King Goujian of Yue
Bronze Dun and Zun Plates from the Shang and Zhou Dynasties
Shang Dynasty Bronze Human Face with Longitudinal Eyes
A copy of the chime bell from Leigudun Tomb No. 2
In 1981, a set of Chime Bells from the Warring States Period was unearthed from Tomb No. 2 in Leigudun, Hubei Province, with accurate rhythm and beautiful timbre. Its number and scale are second only to Zeng Hou Yi chime bells, with a total range of more than 5 octaves. It can be tuned by itself, and various music composed of five-tone, six-tone and seven-tone scales can be played. Five people are required to perform together, and all the voices come out in unison, symphonic and overlapping, which is worthy of being the unparalleled sound of ancient music.
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The second stage - the foundation of the discipline of metallic materials
Lay the foundation of metal materials disciplines: metallography, metallography, phase transformation and alloy steel, etc.
1803: Dalton proposes atomic theory, Avogadro proposes molecular theory.
1830: Hessel proposed 32 crystal types and popularized the crystal index.
1891: Scientists from Russia, Germany, Britain and other countries independently established the lattice structure theory.
1864: Sorby prepares the first metallographic photograph, 9 times, but significant.
1827: Karsten isolated Fe3C from steel, and in 1888 Abel proved that it was Fe3C.
1861: Ochernov proposed the concept of the critical transformation temperature of steel.
At the end of the 19th century: Martensite research has become fashionable, Gibbs obtained the phase law, Robert-Austen discovered the solid solution characteristics of austenite, and Roozeboom established the equilibrium diagram of the Fe-Fe3C system.
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The third stage - the great development of micro-organization theory
Alloy phase diagram, invention and application of X-ray, establishment of dislocation theory.
1912: Discovered X-rays, confirmed that α(δ)-Fe is bcc, γ-Fe is fcc; solid solution law.
1931: Discovery of the expansion and contraction of the γ region of alloying elements.
1934: Russian Polanyi, Hungarian Orowan and British Taylor independently proposed the dislocation theory to explain the plastic deformation of steel; the crystallography of martensitic transformation.
1938: The electron microscope is invented.
1910: A stainless steel was invented, and F stainless steel was invented in 1912.
1990: Invented the Brinell hardness tester, Griffith proposed that stress concentration will lead to microcracks.
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The fourth stage - in-depth study of micro theory
In-depth research on microscopic theory: research on atomic diffusion and its essence; steel TTT curve measurement; bainite and martensite transformation theory formed a relatively complete theory.
Establishment of dislocation theory: The invention of the electron microscope prompted the precipitation of the second phase in steel, the dislocation slip, and the discovery of incomplete dislocations, stacking faults, dislocation walls, substructures, Cottrell air masses, etc., and developed the dislocation theory. wrong theory.
New scientific instruments are constantly invented: electron probe, field ion emission microscope and field electron emission microscope, scanning transmission electron microscope (STEM), scanning tunneling microscope (STM), atomic force microscope (AFM), etc.
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2. Modern metal materials
Research and development of advanced structural materials is an eternal theme.
Develop high-performance structural materials: from the pursuit of high strength, high temperature resistance, corrosion resistance, and wear resistance to reducing mechanical weight, improving performance, and extending service life. A wide range of applications from composites to structural materials, such as aluminum matrix composites. Develop low-temperature austenitic steels for various applications.
Transformation of traditional structural materials: The important way is to have finer and more uniform structures, purer materials, and focus on craftsmanship. The "new generation steel material" is twice as strong as existing steel materials. The "9.11" incident in the United States exposed the poor resistance to high temperature softening of steel structures used in construction, which promoted the development of high-strength hot-rolled fire-resistant and weather-resistant steel.
Develop other high-performance steels: use various new processes and new methods to manufacture new tool steels with good toughness and wear resistance. Economical alloying is a development direction of high-speed steel, and the development of various surface treatment technologies for tool materials is of great significance in the development of new tool materials.
Advanced preparation technology: such as metal semi-solid processing technology, the maturity and application of aluminum-magnesium alloy technology, the technical limit of existing steel and the strengthening and toughening of steel are the directions of efforts.
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3. Sustainable development and trend of metal materials
In 2004, "Materials Industry in a Recycling Society - Sustainable Development of Materials Industry" was proposed.
Microbial metallurgy: waste-free production, already industrially produced in many countries. Copper produced by microbial metallurgy in the United States accounts for 10% of the total output, and sea squirts are artificially cultivated in Japan to extract vanadium. Seawater is a liquid mineral, and the amount of alloying elements contained in seawater exceeds 10 billion tons. Now magnesium, uranium and other elements can be extracted from seawater. About 20% of the magnesium produced in the world comes from seawater, and the United States already meets 80% of the demand for this kind of magnesium.
Recycling material industry: To adapt to the needs of the times, integrate ecological and environmental awareness into the design of products and production processes, improve the utilization rate of materials, and reduce the environmental burden in the process of production and use. Develop an industry that forms a virtuous cycle of "resources→materials→environment".
The mainstream direction of alloy development is low-alloying and general-purpose alloys, forming a green/ecological material system, which is conducive to the recycling and recycling of materials. It is necessary to research and develop green materials and environmentally friendly materials that are closely related to people's lives.
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4. Titanium alloy is called "space metal" and "future steel"
Titanium alloys can maintain high strength at high and low temperatures, and their corrosion resistance is unrivaled. Titanium is abundant in the earth (0.6%). However, the extraction process is complicated, the cost is high, and the wide application is limited. Titanium alloy will be one of the metal materials that will make important contributions to mankind in the 21st century.
5. Non-ferrous metals
Resources are facing a serious problem of unsustainable development, mainly due to serious damage to resources, low utilization rate, and alarming waste. Intensive processing technology is backward, high-end products are lacking; innovative achievements are few, and the industrialization degree of high-tech achievements is not high. The development of high-performance structural materials and their advanced process methods is the mainstream, such as: aluminum-lithium alloys, rapid solidification aluminum alloys, etc. Non-ferrous metal functional materials are also the development direction.
