Experimental Study on a New Test Apparatus for the Surface Damages Combined with Slurry Wear and Cavitation Erosion

1. 采用超声振动空化装置与浆体喷射装置相结合的方法，研究了浆体磨损与空化侵蚀的复合损伤。实验结果如下：(1)当气蚀和浆体侵蚀同时存在时，由于固体颗粒连续地去除表面，不符合每次损伤损失的简单总和，损伤损失随时间成比例增加，没有潜伏期。在低射流速度下，固体颗粒对空化侵蚀有抑制作用。射流速度高时，空化气泡从表面流出，固体颗粒消除了产生侵蚀碎屑的塑性变形，从而减少了空化侵蚀。(2)在含固体颗粒的水中，空化侵蚀加剧。磨料、硅砂等棱角颗粒的损伤增加程度大于玻璃微珠。随着颗粒尺寸的增大，损伤在一定值处达到最大值，然后逐渐减小。提出了含空化泡浆射流作用于静止试样的试验方法。复合损伤大于浆体磨损。为了研究固体颗粒流的冲击磨损特性，设计了一套空气冲蚀试验装置。固体颗粒在室温和高温下对材料的冲击磨损可以根据材料和颗粒的冲击条件和性能来估计。研究结果表明，所研制的试验装置对于研究砂浆磨损及砂浆磨损与空化侵蚀复合损伤具有重要意义。

1. A new test apparatus was constructed by combining an ultrasonic vibratory cavitation device and a slurry jet device in order to study combined damages with slurry wear and cavitation erosion. Experimental results were obtained as follows.(1)When cavitation and slurry erosions are combined, the damage loss increases in proportion to time without an incubation period because solid particles remove the surface successively and does not coincide with simple summation of each damage loss. Under low jet flow velocity, cavitation erosion is reduced by solid particles. When jet flow velocity is high, cavitation bubbles flow out from the surface and the solid particles remove the plastic deformations in which produce the erosion debris, thus the cavitation erosion is diminished.(2)Cavitation erosion increases in water containing solid particles. The degree of the increase of damage is larger for angular particles such as abrasives and silica sands than glass beads. With increasing particle size, the damage shows a maximum at a given value and decreases.2. The test method which slurry jet containing cavitation bubbles acts on the stationary specimen was developed. The combined damage is larger than slurry wear.3. An air-blast erosion test apparatus was constructed in order to investigate the characteristics of wear caused by a stream of impinging solid particles. The wear of materials by impacts of solid particles at room and high temperatures could be estimated from the impinging conditions and the properties of materials and particles.From these results, it is found that the test apparatuses developed in this study are very useful to investigate the slurry wear and the damages combined with slurry wear and cavitation erosion.