Test rings and test blocks used in the ring block test: they are all made of the most commonly used bearing steels, GCr15 and 45# steel. The size of the test ring (outer diameter x width) is Ï†49.24mmÃ—12.7mm, and the size of the test block is 12.35mmÃ—12.35mmÃ—19mm. The different surface roughness required for the test is hand-polished by metallographic sandpaper of different grain sizes. The metallographic sandpaper used in this test has the following types: W40, W20, W10, W7. The surface roughness of the tested test ring and test block basically meets the test requirements. Test ring, test piece surface roughness, hardness and other parameters.
EXPERIMENTAL RESULTS Scanning electron microscopy (SEM) observations were performed by scanning electron microscopy of all etched samples (including test rings and test blocks) in an attempt to find typical etched features. As a result, typical galvanic features were found on the 2# test ring and the 5# test block. The recording condition of the 2# test ring is: the applied voltage is 30V, the rotational speed is 1200r/m, and the applied load is 100g; the working condition of the 5# test block is: the applied voltage is 50V, the rotational speed is 1500r/m, and the applied load is 100g. .
For the electric etch pit (Ã—3000) on the 2# test ring, the discretely distributed etch pits can be clearly seen, where the etched density is small and the diameter of the etch pit is small, indicating that the single etched pulse energy is Low; is the electric etch pit diagram on the 5# test block (Ã—250), the electric etch pit is discretely distributed, and the etched density is small. In comparison, the etch pit is larger and deeper, indicating a single eclipse pulse energy. Bigger.
The test ring number and parameter number are the piece of electro-etching pit (Ã—4000) on the 2# test ring. The electric erosion density is large, and it can be clearly seen that the electric corrosion pit is connected into one piece, and the large metal piece next to it falls off; The crack diagram (Ã—3500) in the etch pit on the test block shows that the temperature in the discharge channel is very high during the galvanic discharge, so that the metal next to it is burnt out, which confirms that the discharge channel is a cold plasma with a temperature of about 10000K. body.
The coefficient of friction coefficient and the change of temperature with time curve of the coefficient of friction reflect the whole process of forming and developing from the formation of electrical erosion to other gear failure modes at this voltage level. This has been observed by the above scanning electron microscope. (SEM) observation confirmed; for the temperature versus time curve, since the friction surface contact condition changes continuously during the electric erosion process, the surface contact condition deteriorates with the change of the friction coefficient, so that the temperature is continuously increased.
Conclusion 1) The typical morphological features of electro-erosion were found on some specimens, indicating that the surface of the specimen was electrically etched. At the same time, it showed that the eclipse could be reproduced by simulation test. 2) The applied voltage was 30V when the galvanic corrosion occurred. ~50V, which means that the lubricating oil film has a certain withstand voltage value (breakdown voltage) under a certain instantaneous steady state. Only when the peak value of the applied voltage exceeds the withstand voltage value of the lubricating oil film, electric erosion may occur; 3) electricity The process of eclipse wear is an acceleration process. From the very beginning, after a period of time, when the contact surface quality is seriously damaged or the surface metal loss is excessive, other failure modes will work together to compound failure, which accelerates the wear loss rate. ; 4) Prove the correctness of the electric erosion theory and the feasibility of the electric erosion simulation test method.
Wuhan Wide Uv Led Inkjet Printer widely used in different material direct printing, like glass, ceramic, metal plate, wood, acrylic panel, KT board, PVC sheet, Melamine Sheet, Marble Board, plastic film, leather, textile etc.
We Flatbed Uv Printer adopt industrial level printing head toshiba and Richo, Printing speed reach 34M/M
UV Flatbed Printer 3020
Uv Flatbed Printer,Flatbed Printer,Digital Uv Flatbed Printer,Digital Flatbed Printer
Wuhan HAE Technology Co., Ltd. , http://www.chinahae.com