新型低成本ZrO2-SiC-Al2O3高性能耐磨陶瓷的制备及磨损性能研究

In order to resolve the extrude problems, i.e., the short life and high cost of wear-resistant materials of the drilling equipments resulted from the abnormal failure damage under the complex working conditions with high temperature and high pressure, this project has proposed innovatively to investigate the key scientific issues on the optimization of the preparation and wear-resisting properties of novel ZrO2-SiC-Al2O3 ceramics, which are manufactured by introducing Al2O3 and sintering aids rare earth oxide as well as the carbonthermal reduction products ZrO2 and SiC using the zircon as the main raw material. The contents of this research include: (i) the regulation and control of the phase composition and morphology of ZrO2-SiC powders transformed from zircon, (ii) the optimized sintering technology of ZrO2-SiC-Al2O3 wear-resistant ceramics, (iii) the performance evaluation and wear mechanisms of the liquid-solid dual phase flow erosion wear, abrasive wear and high temperature erosive wear of the produced ZrO2-SiC-Al2O3 ceramics, etc. Thereby, we can obtain the optimization process parameters on the preparation of low-cost and high-performance ZrO2-SiC-Al2O3 wear-resistant ceramics, explore the basic theory on the regulation of phase compositions transformed from the zircon, and establish an empirical model on the relationship between the wear resistance properties of SiC-Al2O3-ZrO2 ceramics and their working conditions. This project has a great significance for the low cost and long life of wear-resistant ceramic materials applied in exploiting the deep geological and mineral resources.

本项目为解决高压高温复杂工况条件下钻探设备和井下机具用耐磨材料的异常失效寿命短和成本高的突出问题，进行以锆英石为主要原料，通过其碳热还原物相转变为ZrO2和SiC，在此转型原料的基础上引入少量Al2O3和稀土氧化物助烧剂，研究新型ZrO2-SiC-Al2O3耐磨陶瓷制备及其磨损性能优化的关键问题。研究内容包括锆英石转型ZrO2和SiC的物相组成和微观形貌调控机理、ZrO2-SiC-Al2O3耐磨陶瓷的优化烧结技术、ZrO2-SiC-Al2O3陶瓷的液固两相流冲蚀磨损、磨粒磨损和高温冲蚀磨损的评价和磨损机制等，获得新型低成本ZrO2-SiC-Al2O3高性能耐磨陶瓷制备的优化工艺参数，探讨锆英石转型的物相组成调控的基础理论，建立ZrO2-SiC-Al2O3耐磨陶瓷磨损与工况条件关系的经验模型。本项目对我国深部地质资源勘探和矿产资源开采所用的耐磨陶瓷的高效低成本长寿命化具有重要意义和价值。

本项目为解决高压高温复杂井下工况条件下钻探设备和井下机具用耐磨材料的异常失效寿命短和成本高的突出问题，研究了以锆英石为主要原料，通过其碳热还原物相转变为ZrO2和SiC，在此转型原料的基础上引入少量Al2O3和稀土氧化物助烧剂，实现制备新型ZrO2-SiC- Al2O3耐磨陶瓷及其磨损性能优化的关键技术。项目系统研究了反应温度、保温时间、还原剂种类及用量、氧化物添加剂种类及用量对锆英石碳热还原物相组成和显微形貌的影响，获得了锆英石碳热还原制备ZrO2-SiC复相粉体的优化温度、优化保温时间、还原剂种类及用量和氧化物添加剂种类及用量等优化工艺参数及其对产物物相组成和微观形貌的影响规律，揭示了锆英石转型ZrO2和SiC的物相调控机理和氧化物添加剂对锆英石转型制备稳定ZrO2或部分稳定ZrO2和SiC的影响机制；研究了氧化脱碳工艺对锆英石碳热还原反应产物物相组成的影响规律及产物中锆、硅和氧元素的赋存状态，获得了锆英石碳热还原产物的优化脱碳工艺；研究了烧结温度、保温时间、Al2O3添加剂用量等因素对ZrO2-SiC-Al2O3耐磨陶瓷烧结性能、显气孔率、体积密度、抗折强度、断裂韧性和维氏硬度的影响规律，获得了优化工艺参数和烧结工艺；采用转盘式冲蚀试验机系统评价了ZrO2-SiC-Al2O3耐磨陶瓷的抗液固两相流冲蚀磨损性能，研究了不同冲蚀时间、不同冲蚀粒子种类、不同液相介质种类等因素对ZrO2-SiC-Al2O3耐磨陶瓷试样耐液固两相流冲蚀磨损行为的影响规律，探讨了ZrO2-SiC-Al2O3耐磨陶瓷的常温力学性能与液固两相流冲蚀磨损性能的相互关系，获得ZrO2-SiC-Al2O3陶瓷液固两相流冲蚀磨损的评价机制；采用磨粒磨损试验机模拟研究了不同压力条件下ZrO2-SiC-Al2O3耐磨陶瓷的磨粒磨损行为，探讨不同胶轮转速、不同载荷、不同磨损粒子种类等因素对ZrO2-SiC-Al2O3耐磨陶瓷试样耐磨粒磨损行为的影响规律，获得了ZrO2-SiC-Al2O3陶瓷的磨粒磨损性能的评价机制。结果表明制备的ZrO2-SiC-Al2O3耐磨陶瓷具备在高压高温复杂工况条件下用作钻探设备和井下机具潜在的耐磨材料性能优势，这为我国深部地质资源勘探和矿产资源综合利用开发用高效低成本长寿命化耐磨陶瓷研究奠定坚实基础。