螺杆泵螺杆纳米掺杂陶瓷涂层显微结构研究

利用大气等离子喷涂技术（APS），在7.5m螺杆泵螺杆基体表面上制备纳米掺杂30%AT13(Al₂O₃+13%TiO₂)陶瓷涂层，采用Philips XL-30型扫描电镜（SEM）、能谱（EDS）和Philips X-port型X射线衍射仪（XRD）等现代分析手段对纳米掺杂AT13等离子喷涂粉末及螺杆表面等离子喷涂涂层的显微组织、物相进行了观察测定。结果表明：纳米掺杂等离子喷涂粉末结构呈微米级粒子表面包覆纳米粒子的麻团状，尺寸在50~70μm内，流动性好，适用于大气等离子喷涂。纳米掺杂使等离子喷涂涂层元素分布均匀性提高，孔隙度降低，涂层内出现（Al₂O₃）_5.333与斜方晶态的Al₂TiO₅物相。涂层断口分析证明：在纳米掺杂30%的涂层中，出现大量直径约为10nm的蠕虫状晶须，断裂方式变为韧性的穿晶断裂，为纳米掺杂螺杆使用寿命成倍的提高提供了理论依据。

Microstructure of Plasma Spraying Ceramics Coating Doping Nanometer on Screw-pump

On the selfmanufactured plasma spraying profile modeling machine,the 7.5 meters screws are dealt with plasma spraying of nanophase doped with Al2O3+13%TiO2.AT13 ceramics coating doped 30% nanometer prepared by ash plasma spraying method.The microstructure and the phase of AT13 plasma spraying powder and ceramics coating with doping nanometer and prefabricating are investigated by modern material analysis means such as SEM and EDS and XRD etc.The results show that the powder structure using plasma spraying doping nanometer is micrometer and the cladding nanometer in its surface is hemp regiment structure,the fluidity of the powder is good in 50~70μm and indicated to the ash plasma spraying.The doping nanometer will improve the homogeneity of element distribution in plasma spraying ceramics coating and reduce porosity and make the inner of the ceramics coating appear（Al₂O₃）_5.333 and Al₂TiO₅ phase by orthorhombic crystalline state.The analysis of the ceramics coating fracture proves that volumes of vermiculate whiskers with 10nm diameter are found in ceramics coating doping nanometer,the fracture method become the trans-granular fracture with toughness.The analysis of the fracture illustrates that a great amount of 10nm nano-crystals,which changes the fracture mechanism and provides the structure evidence for the long-life of the screw-pump.