| Piezoelectric pump is a kind of miniature pump that use the bendingdeformation of piezoelectric vibration to change airtight pump cavity volume and toachieve the fluid transmission. Its research institutions are all over the world. Due tothe piezoelectric pump has the advantages of simple structure, low energyconsumption, small size, high precision, no electromagnetic interference, easyintegration, easy to control, it has been widely used in aviation spacecraft, medicalequipment, precise chemical, biological, genetic engineering, computer electricalengineering, and many other fields.However, piezoelectric components are usually used in the circulation of thealternating electric field or in the field (field, electric field, temperature field) undercontinuous working. After long time working, it will appear many problems such ascrack initiation and propagation, fatigue fracture or even depolarization. Even worseit will lead to the failure of piezoelectric components. This will seriously limit theapplications of piezoelectric components in the field of MEMS aspects. At the sametime, along with the development of piezoelectric pump product’s practical,Serialization and marketing, we need to do more research on the stability of thepiezoelectric pump product testing, failure modes analysis and the fatigue life ofproduct and so on.Therefore, from the above point of view, this article hopes to make analysis offatigue life and failure types of piezoelectric vibrator and piezoelectric pumpproduct. Analyze the failure mode and fatigue life through the fatigue simulation ofvibrator, fatigue test and piezoelectric pump accelerated life test, so as to lay thefoundation for the piezoelectric pump marketing. The main research contents are asfollows: Analyze the failure modes of piezoelectric ceramics, mainly divided intomechanical fatigue and fatigue. Mechanical fatigue mainly lead to the failure ofceramic fracture, and electric fatigue easily lead to occurrence of depolarization orceramic dielectric breakdown.Using the Miner linear fatigue damage accumulation theory and ANSYSsoftware to analyze the fatigue simulation of piezoelectric vibrator, we obtained thefatigue consumption coefficient of single chip piezoelectric vibrator and the fatiguestability of the vibrator within six months. We also study the effects of differentstructural parameters on the fatigue life of the piezoelectric vibrator and optimize thevibrator parameters.Obtained the relationship between voltage load and vibrator performance andcycle times from the fatigue test of the piezoelectric vibrator, and determine the9level cyclic fatigue failure grading from the view of reliability. The test result isqualified. Compare self-adhesive vibrator and imported vibrator at fatiguecharacteristics. Get the cycle number of vibration part when vibrator is completelydestroyed by continuing putting high voltage loop fatigue test to the vibrator. Drawthe general P-S-N curves of the piezoelectric vibrator according to the tracing pointmethod and curve fitting.According to the failure truncation constant-stress accelerated life test ofpiezoelectric pump, we obtained the characteristic life, acceleration coefficient,failure rate, the instantaneous and average failure rate, mean life and reliable life ofPSD35piezoelectric pump products. The result shows that the life time of thePSD35piezoelectric pump under the rated voltage130V(367Vpp) is around5102hours with the reliability of0.95.Analyze the failure type of piezoelectric pump fatigue failure. The failure typesmainly as follows:1. the piezoelectric vibrator is damaged;2. plastic deformation ofpassive valve;3. failure performance of the seal;4. channel blockage. And theimprovement measures are as follows: selection excellent vibrator, proper selection of working voltage, improving valve processing technology, precise positioning ofseals installation and fluid filtration and purification treatment. |
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