【作者】 李阳；

【导师】 梁淑华； 邹军涛；

【作者基本信息】 西安理工大学 ， 材料加工工程， 2015， 硕士

【摘要】 CuW合金是由具有良好的导电性、导热性的铜和高熔点、高密度及低膨胀系数的钨组成的一种性能优良的假合金,被广泛地应用于高压电器行业,尤其是高压断路器中的触头材料。在“十二五”规划中,我国将进一步建设国家电网以满足国民生产不断增长的需要,因此,直流输电以及超高压特高压输电将作为国家电网建设的主要目标,但是当前,CuW合金还不能完全满足高等级输电断路器、隔离开关所涉及关键材料的性能要求,这就为科研人员提出了亟需解决的工程难题。目前,主要采用熔渗法制备CuW合金,以及在CuW合金中加入微量或少量的合金元素改善Cu与W的烧结效果,这些合金元素主要起活化烧结作用,但是合金元素活化烧结对CuW合金性能提高幅度有限。触头工作时,在插拔过程中,动触头在静触头的径向施加作用力,高频次插拔会造成静触头变形失效。因此,在径向添加钨纤维网所形成的混杂结构能够抵抗变形,从而提高触头的使用寿命。所以,采用纤维与颗粒混杂结构制备CuW合金成为本文研究思路。本文在制备CuW合金过程中,通过在预制钨骨架中添加不同种类的钨纤维网与颗粒形成混杂结构,并采用热压-熔渗法来制备CuW合金,利用扫描电子显微镜对CuW合金组织形貌进行分析表征,通过对比分析CuW合金电导率、密度、硬度及强度等性能的变化,获得纤维与颗粒混杂结构增强CuW合金的强化机理。研究结果表明:(1)采用热压-熔渗法可以减弱CuW合金中铜相富集的现象,使钨纤维与钨颗粒较好结合,从而获得良好性能。(2)在CuW合金受力拉伸、弯曲或压缩时,钨纤维网在CuW合金中能够均匀承受作用力,从而提高CuW合金抵抗变形的能力。(3)在钨纤维表面磁控溅射一层金属Cr,可以促进钨纤维与钨颗粒冶金结合,使钨纤维与钨颗粒产生更多的烧结颈,以提高CuW合金的强度。更多还原

【Abstract】 The CuW alloy has excellent performance.It is composed of copper which has high conductivity and thermal conductivity and tungsten which has high strength,higher melting point,higher density and lower expansion coefficient.It is widely used in various fields,especially in all kinds of high voltage circuit breaker contactor material.In the 12th Five-Year Plan,China will further build a national grid to meet the growing needs of the national product and,therefore,the DC transmission and high voltage UHV transmission will be the main objective of the national power grid construction.But currently the domestic CuW alloys can not meet the performance requirements of the key materials in the electric such as high-grade transmission of circuit breakers and isolating switches,which poses a problem which must be solved to researchers.At present mainly manufacture CuW alloy by infiltrating.Add trace or a few alloy elements to the CuW alloy to improve Cu and W sintering effect,and the alloy elements mainly plays the role of activated sintering.But the CuW alloy current performance increase was limited.In the process of plug,dynamic contactor stress on the static contact in the radial,under the effect of high frequency insertion,causing the deformation failure of static contact.Consequently,tungsten fibres were added in the radial can resist deformation,thus improving the service life of the contact.Therefore fibers and particles hybird reinforcing the property of CuW alloy has become a research idea.CuW alloys were prepared by the hot-pressing and sintering-infiltration method.In the preparation process add the different kinds of tungsten webs in the prefabricated tungsten skeleton to enhance the properties of CuW alloys.Analyze microstructure and state of CuW alloy by scanning electron microscopy.According to the changing rules of electrical conductivity,density,hardness,strength of the CuW alloy to verify the strengthening effect of the tungsten fibers.The results are as follows:(1)Using the hot-pressing and infiltration compound craft can reduce copper phase enrichment phenomenon in the CuW alloy and make tungsten webs combine with tungsten particles better.(2)During the CuW alloy were drawed or bended,tungsten webs can form a continuous structure which can sustain force equably to improve the tensile strength and bending strength of CuW alloy.(3)Plating Cr on the surface of the tungsten fibers can make tungsten webs metallurgically combine with tungsten particles.Then tungsten webs and tungsten particles can generate more sintering necks.The strength of CuW alloy was improved.更多还原