The present invention relates to a frictional wear testing apparatus and frictional wear testing method for measuring wear resistance (anti-abrasion) characteristics of metal material or ceramic material.
Since ceramics are very hard, in the case where the evaluation of the wear resistance characteristics is performed in a general frictional wear testing method such as a pinion disc method or an abrasion testing method, the wear is hardly, developed. As a result, the measurement takes a long time and the measurement error is also remarkable. Then, in order to solve this problem, an erosion frictional wear test is proposed as a frictional wear testing method.
In this erosion frictional wear test, injection material containing grinding particles in an accelerated gas flow is injected onto a test piece such as a ceramic member for a constant period of time, and the mass reduction or the frictional worn volume of the test piece is measured for the evaluation. This is a very simple method because a size of the test piece to be used is such as a bending strength test piece defined by JIS (Japanese Industrial Standards), for example. In addition, the test is superior in produceability of data. Thus, the test has excellent features in comparison with the general frictional wear tests.
However, in the method such as an erosion frictional wear test using the injection material which is obtained by mixing air and grinding particles, since the grinding particles and the cutting debris of the test piece is likely to fly and drift in the air, it is necessary to enhance air-tight property of an injection chamber in order to prevent the grinding particles or the like from leaking to the outside of the injection chamber. Also, it is necessary to provide a device such as a dust collection filter or a cyclone for collecting the particles or the like. The overall apparatus is large in size and complicated in construction, resulting in increased cost.
Also, since the particles drift for a while after the injection material has been injected, if the injection chamber is opened to pick up the test piece immediately after the completion of the test, there is a fear that the particles would be dispersed to the outside. Accordingly, in the case where the test piece is picked up after the completion of the test, one has to wait until the grinding particles drifting in the injection chamber are completely removed. Therefore, it takes a long time for one measurement.
Also, in the method for mixing the grinding particles into the accelerated air flow, the collision force by which the grinding particles are collided against the test piece depends upon the humidity. In addition, the higher the humidity, the more the error will become. It is necessary to set the humidity at a constant level for every measurement within the injection chamber in order to suppress the measurement error. Accordingly, the conventional method suffers from a problem that the testing operation is very complicated and troublesome.