Thermal conductivity of pure tungsten at various temperatures

<strong>Thermal conductivity of pure tungsten at various temperatures</strong> Junjie Chen Contributor: Junjie Chen, ORCID: 0000-0001-5055-4309, E-mail address: [e-mail], Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China Tungsten, or wolfram, is a chemical element with the atomic number 74. Tungsten is a rare metal found naturally on Earth almost exclusively as compounds with other elements. It was identified as a new element in 1781 and first isolated as a metal in 1783. Its important ores include scheelite and wolframite, the latter lending the element its alternate name. The free element is remarkable for its robustness, especially the fact that it has the highest melting point of all known elements barring carbon. It also has the highest boiling point. Its density is 19.30 grams per cubic centimetre, comparable with that of uranium and gold, and much higher than that of lead. Polycrystalline tungsten is an intrinsically brittle and hard material, making it difficult to work. However, pure single-crystalline tungsten is more ductile and can be cut with a hard-steel hacksaw. Tungsten occurs in many alloys, which have numerous applications, including incandescent light bulb filaments, X-ray tubes, electrodes in gas tungsten arc welding, superalloys, and radiation shielding. Tungsten's hardness and high density make it suitable for military applications in penetrating projectiles. Tungsten compounds are often used as industrial catalysts. In its raw form, tungsten is a hard steel-grey metal that is often brittle and hard to work. Purified, monocrystalline tungsten retains its hardness, and becomes malleable enough that it can be worked easily. It is worked by forging, drawing, or extruding but it is more commonly formed by sintering. Of all metals in pure form, tungsten has the highest melting point, lowest vapor pressure, and the highest tensile strength. Thermodynamic temperature (degrees kelvin), Thermal conductivity (watts per meter-kelvin) 10 9710 100 208 293 173 1000 118 2000 98<strong>不同温度下纯钨的热导率</strong> 陈俊杰 贡献者：陈俊杰，ORCID：0000-0001-5055-4309，电子邮箱：[e-mail]，河南理工大学机械与动力工程学院能源与动力工程系，中国河南省焦作市世纪大道2000号，454000。钨（wolfram）是原子序数为74的化学元素。钨是一种稀有金属，在自然界中几乎仅以与其他元素形成化合物的形式存在。1781年，钨被确认为新元素，并于1783年首次被分离为金属单质。其重要矿石包括白钨矿和黑钨矿，后者亦是该元素别名的来源。单质钨以其坚固性闻名，尤其是在除碳以外的所有已知元素中拥有最高熔点的特性，同时它也拥有最高的沸点。其密度为19.30克每立方厘米，与铀和金相当，远高于铅。多晶钨本质上兼具脆性与高硬度，因此难以加工。然而纯单晶钨的延展性更强，可使用硬钢手锯进行切割。钨可被用于制备多种合金，应用场景广泛，包括白炽灯泡灯丝、X射线管、钨极气体保护电弧焊（gas tungsten arc welding）电极、高温合金以及辐射屏蔽材料。钨的高硬度与高密度使其适用于军事穿甲弹领域。钨化合物常被用作工业催化剂。以原料形态存在的钨为硬钢灰色金属，通常脆性大且难以加工。经过提纯的单晶钨仍保留其硬度，同时延展性提升至可轻松进行加工的程度。其加工方式包括锻造、拉拔或挤压，但更常见的加工方式为烧结成型。在所有纯金属中，钨拥有最高的熔点、最低的蒸气压以及最高的抗拉强度。热力学温度（thermodynamic temperature，单位：开尔文）、热导率（thermal conductivity，单位：瓦/(米·开尔文)），对应数据为：10 9710、100 208、293 173、1000 118、2000 98