Rare metals in the hottest knives

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The rare metal in the tool

is tungsten first

the most traditional high-speed steel W18Cr4V contains 18% tungsten. Later, typical W6Mo5Cr4V2 (M2) and W9Mo3Cr4V also contained 6% and 9% tungsten. The tungsten content of cemented carbide is also very high. The tungsten carbide content of tungsten cobalt (commonly used for processing cast iron and aluminum alloy, such as the domestic typical YG series) or tungsten cobalt titanium (commonly used for processing long chip steel, such as the domestic typical YT Series) is basically more than 80%, such as the tungsten carbide content of YG6 is more than 90%

China ranks first in the world in tungsten reserves, accounting for 85% of the global supply. Tungsten is mainly used in cemented carbide, special steel including high-speed steel and other products, and is widely used in the national defense industry, aerospace, information industry, known as the "teeth of industry". Tungsten has very good temperature resistance, so tungsten alloys are widely used in the weapon industry, such as tungsten alloys used in gun and gun launch tubes. In the military, the projectiles used as armor piercing projectiles are made of high-density alloy steel, tungsten carbide and other materials that are much harder than tank armor. The chemical properties of tungsten are very stable, and it will not oxidize and its hardness will not decrease significantly at high temperatures above 1000 ℃. This is very beneficial to the high-temperature metal jet of armor piercing projectile. The mechanical properties of tungsten alloy are almost the same as those of depleted uranium, but there is no radioactivity of depleted uranium, which is conducive to environmental protection. Tungsten has a very high hardness, which is mainly used as an alloy for steel metals. The hardness of steel will be greatly improved after adding tungsten. High speed steel, a tool material in the field of metal processing, is an alloy containing tungsten. If a country does not have tungsten, there will be a great lack of metal processing capacity under the current technical conditions, which will directly lead to the paralysis of the machinery industry, so it is called strategic metal. In addition, tungsten must also be used as filament in the field of lighting

molybdenum should be the second

high speed steel is divided into two major systems: Tungsten system and tungsten molybdenum system. Due to the shortage of tungsten resources and the good processability of tungsten molybdenum high speed steel, tungsten molybdenum high speed steel has become the mainstream faction of high speed steel. In high-speed steel, one part of molybdenum contributes about two parts of tungsten to tool performance. Therefore, we will see that the "tungsten equivalent" of W6Mo5Cr4V2 (M2) is 16%, and the "tungsten equivalent" of W9Mo3Cr4V is 15%. China's Molybdenum reserves rank second in the world, accounting for 24% of the global supply. Molybdenum can be used to refine all kinds of alloy steel, stainless steel, heat-resistant steel and super alloy. It is widely used in military industry, also known as "war metal"

in addition, titanium, cobalt, chromium, niobium, tantalum, etc. are also rare metals commonly used in cutting tools

titanium is the main component of another kind of cemented carbide titanium based cemented carbide (which is often called "cermet" in China). Titanium based cemented carbides are cemented carbides with tic or Ti (C, n) as the main component (accounting for more than 60% ~ 80%), and Ni Mo or Ni Co Mo as the bonding phase. The performance of titanium based cemented carbide is between ceramic and WC based cemented carbide, which can be roughly judged from the external running state of the variable-frequency single column tensile testing machine; If nothing abnormal can be seen from the outside, tungsten based cemented carbide can be cut at a higher cutting speed, and the surface quality of the machined workpiece is good. Therefore, it is especially suitable for finishing and semi finishing of steel and castings. In foreign countries, the proportion of TiC based and Ti (C, n) based cemented carbides has reached more than 30% of the total demand for indexable blades. In recent years, with the development of coated titanium based cemented carbide (single coating or multi-component composite coating), ultra-fine grain, nano grain and gradient structure titanium based cemented carbide, the comprehensive properties of the materials have been greatly improved and the scope of application has been expanded

titanium is also one of the most important components of tool coating. Tic, tin, Ti (CN), TiAlN, etc. are our most common coating varieties

it is understood that China's titanium resources account for about 38% of the global titanium resources, and the total reserves of TiO2 converted into more than 9 billion tons, ranking first in the world. Most of them are in Panzhihua area. Titanium has the highest specific strength (ratio of tensile strength to density) of all industrial metal materials: the density of titanium is 4.54 g/mm, the tensile strength of titanium is up to 180 kg/mm, the extrusion strength is 40% - 55%, the overall strength is twice that of aluminum, and the specific strength is 1.3 times that of aluminum; And it can maintain such high strength in a wide temperature range from -253 ℃ to 500 ℃. Titanium has been mainly used in aerospace and military precision components

the role of cobalt in high-speed steel cutting tools I have mentioned in the article "rambling high speed steel": cobalt also plays an obvious role in improving the properties of high-speed steel. It can promote carbides to dissolve more in the matrix during quenching and heating, and use high matrix hardness to improve wear resistance. This kind of high-speed steel has good hardness, thermal hardness, wear resistance and grindability

The main function of cobalt in cemented carbide is binder, which can provide certain toughness for cemented carbide tools. The tool with less cobalt content has higher hardness, but its toughness is often not enough. Therefore, people often use the method of increasing cobalt content to appropriately reduce hardness and improve toughness. Because once the tool breaks, no matter how high the wear resistance is. Cobalt strengthening is a new solution found later. It can maintain the high hardness of the cemented carbide core to provide sufficient support, while the surface has a higher cobalt content and can withstand higher chip impact. It is said that Kunming Hengda Technology Co., Ltd. is composed of natural persons, Kunming University of technology, Hongta Innovation Investment Co., Ltd. and other shareholders. It was developed with the participation of Dr. Liu Yixiong, a Chinese scientist serving in kena metal in the early years (the brand name was kc850 at that time). Now, Sandvik Keleman and Sangao have also provided such products

however, China's Cobalt resources are in short supply, and the proven cobalt metal reserves are estimated to be about hundreds of thousands of tons. Distributed in 24 provinces (regions) of the country, Jinan gold testing tensile machine is. Foreign countries are rich in cobalt resources, with reserves of about 5.2 million tons, but most of them are produced in weathered laterite nickel ore, magmatic copper nickel sulfide ore and sedimentary sandstone copper ore. 9 Changping will introduce 45 scientific research experts within three years, with more than 5% concentrated in a few countries such as the Democratic Republic of Congo, Australia, Cuba, Zambia, New Caledonia and Russia

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