Saha Gobinda C, Khan Tahir I, Glenesk Larry B
Hyperion Technologies Inc., 6732 8th Street NE, Calgary, Alberta, Canada T2E 7H7.
J Nanosci Nanotechnol. 2009 Jul;9(7):4316-23. doi: 10.1166/jnn.2009.m52.
Oil sands deposits in Northern Alberta, Canada represent a wealth of resources attracting huge capital investment and significant research focus in recent years. As of 2005, crude oil production from the current oil sands operators accounted for 50% of Canada's domestic production. Alberta's oil sands deposits contain approximately 1.7 trillion barrels of bitumen, of which over 175 billion are recoverable with current technology, and 315 billion barrels are ultimately recoverable with technological advances. A major problem of operating machinery and equipment in the oil sands is the unpredictable failure from operating in this highly aggressive environment. One of the significant causes of that problem is premature material wear. An approach to minimize this wear is the use of protective coatings and, in particular, a cermet thin coating. A high level of coating homogeneity is critical for components such as bucketwheels, draglines, conveyors, shovels, heavyhauler trucks etc. that are subjected to severe degradation through abrasive wear. The identification, development and application of optimum wear solutions for these components pose an ongoing challenge. Nanostructured cermet coatings have shown the best results of achieving the degree of homogeneity required for these applications. In this study, WC-17Co cermet powder with nanocrystalline WC core encapsulated with 'duplex' Co layer was used to obtain a nanostructured coating. To apply this coating, high velocity oxy-fuel (HVOF) thermal spraying technique was used, as it is known for producing wear-resistant coatings superior to those obtained from plasma-based techniques. Mechanical, sliding wear and microstructural behavior of the coating was compared with those of the microstructured coating obtained from spraying WC-10Co-4Cr cermet powder by HVOF technique. Results from the nanostructured coating, among others, showed an average of 25% increase in microhardness, 30% increase in sliding wear resistance and a significant increase in the dry sand abrasion wear resistance when compared with the microstructured coating.
加拿大艾伯塔省北部的油砂矿床蕴含着丰富的资源，近年来吸引了巨额资本投资和大量的研究关注。截至2005年，当前油砂运营商的原油产量占加拿大国内产量的50%。艾伯塔省的油砂矿床含有约1.7万亿桶沥青，其中超过1750亿桶可通过现有技术开采，随着技术进步，最终可开采量为3150亿桶。在油砂中操作机械设备的一个主要问题是在这种极具侵蚀性的环境中运行时会出现不可预测的故障。该问题的一个重要原因是材料过早磨损。减少这种磨损的一种方法是使用防护涂层，特别是金属陶瓷薄涂层。对于斗轮、拉铲挖掘机、输送机、铲子、重型运输卡车等因磨料磨损而严重退化的部件，涂层的高均匀性至关重要。为这些部件识别、开发和应用最佳磨损解决方案是一项持续的挑战。纳米结构金属陶瓷涂层在实现这些应用所需的均匀度方面显示出最佳效果。在本研究中，使用具有纳米晶WC核心并包裹有“双相”Co层的WC-17Co金属陶瓷粉末来获得纳米结构涂层。为了应用这种涂层，采用了高速氧燃料（HVOF）热喷涂技术，因为众所周知，该技术能生产出比基于等离子体技术获得的涂层更耐磨的涂层。将该涂层的力学性能、滑动磨损和微观结构行为与通过HVOF技术喷涂WC-10Co-4Cr金属陶瓷粉末获得的微观结构涂层进行了比较。与微观结构涂层相比，纳米结构涂层的结果表明，其显微硬度平均提高了25%，滑动耐磨性提高了30%，干砂磨料磨损抗性显著提高。
