提高钻探用金刚石复合片耐热性的研究

发布时间：2018-05-09 19:29

  本文选题：聚晶金刚石复合片 + 高温高压合成工艺　； 参考：《吉林大学》2017年硕士论文

【摘要】：聚晶金刚石复合片(Polycrystalline Diamond Compact,简称PDC)是一种复合型超硬材料,是通过将金刚石微粉烧结在硬质合金基体上而得到的一种兼具两种材料优异性能的新型材料。同其它材料相比,它既具备聚晶金刚石材料优异的导热性能、超高硬度以及超高耐磨性,又具备硬质合金材料的高强度和抗冲击韧性,所以PDC被广泛应用于工业切削刀具以及石油天然气开采、煤炭开采、地质勘探和岩心钻进等领域。传统的PDC在钻进硬岩过程中会由于摩擦而产生大量的热,使金刚石向石墨发生转化,降低PDC钻头的性能。因而需要对钻探用PDC进行提高耐热性的研究。本文在国家自然科学基金委面上项目 硬岩钻探用金刚石复合片仿生结构设计及强韧化机理‖(编号为41572357)的资助下,对提高PDC的耐热性能进行了试验研究。采用国产铰链式6×1200MN型六面顶压机,用熔渗法结合混合粉末烧结的方法进行PDC的合成试验,确定的合成条件为:压力5.0~6.5GPa,温度1350~1650℃,合成时间5~7min。对影响PDC合成及耐热性的一些因素进行了试验分析和优化设计:(1)对压机腔体内叶蜡石块的组装工艺对PDC合成及其耐热性的影响进行了试验分析与改进;(2)对温度压力条件对PDC合成及其耐热性的影响进行了分析;(3)确定了合成工艺曲线及合成方式,并分析了其对PDC耐热性的影响;(4)确定了两种提高PDC耐热性能的添加剂体系(Co-Si-B体系和Ni-Ti-B体系),并对其组分和配比进行了试验分析确定。采用SEM、EDS能谱分析、XRD等分析手段对两种体系的PDC的微观形貌、成分分布进行了研究。结果表明,合成的PDC中金刚石均质性较好、颗粒大小均匀,性能表现优异,在合成的过程中形成了耐热的金属陶瓷复合相。对试验合成的PDC的耐热性进行了差重热重分析测试,结果表明:常规PDC的抗氧化温度一般为760℃,本文合成的两种体系的PDC的抗氧化温度分别为840℃和920℃,耐热性分别提高了80℃和160℃。对使用熔渗结合混合粉末烧结方法高温高压合成的高耐热性能PDC的合成机理进行了分析。混合粉末的存在为熔渗金属提供了渗透的通道,而熔渗金属在高温高压条件下与复合界面附近产生的压力差则为PDC合成的熔渗过程提供了驱动力,通过添加剂与金刚石之间形成C-M-C(金刚石-金属-金刚石)键的结合模式,提高了PDC中聚晶层的耐热性能。
[Abstract]:Polycrystalline Diamond Compact (PDC) is a kind of composite superhard material, which is obtained by sintering diamond powder on cemented carbide matrix. Compared with other materials, it not only has excellent thermal conductivity, ultra-high hardness and ultra-high wear resistance of polycrystalline diamond materials, but also has high strength and impact toughness of cemented carbide materials. Therefore, PDC is widely used in industrial cutting tools, oil and gas mining, coal mining, geological exploration and core drilling. In the process of drilling hard rock by traditional PDC, a large amount of heat will be produced due to friction, which will transform diamond into graphite and reduce the performance of PDC bit. Therefore, it is necessary to improve the heat resistance of PDC for drilling. In this paper, with the aid of bionic structure design and strengthening and toughening mechanism of diamond composite sheet used for drilling hard rock in the project of National Natural Science Foundation of China (No. 41572357), an experimental study has been carried out to improve the heat resistance of PDC. The synthetic test of PDC was carried out by means of infiltration combined with mixed powder sintering in a 6 脳 1200MN type hexahedral top press made in China. The synthetic conditions were determined as follows: pressure 5.0 ~ 6.5GPa, temperature 1350 ~ 1650 鈩，

本文编号：1867124