Study Of The Impact-sliding Wear Testing Rig And Testing On The PTFE Composite Material

At present, severe service conditions including high sliding velocity, highfrequency, extreme high temperature, high load, becomes more and more continual inthe application of aviation and aerospace, therefore the wear problem of bearing andsealing becomes increasingly serious. Impact-sliding wear is a kind of serious wearbetween wear parts. And as a good self-lubrication material, PTFE composite materialis widely used in the aviation and aerospace. Hence this article mainly researches thewear of PTFE composite material under impact-sliding contact, analyze its wearmechanisms, and provide guidance for this friction pair in the practical engineering.For a more realistic simulation of the bearing cage and high-speed mechanicalclearance sealed state, it requires the use of the ring-to-ring friction pair. Therefore wedesign a new type of impact-sliding wear testing rig, finishing the selection of sensorand calibration, and using the finite element analysis for key components.A multi-function data acquisition system is built to finish the real-time acquisitionof the sensor output signals, which has the advantages of moved convenient, stableoutput, simple connection and multi-function, and can also be applied to differentsystems.A four levels orthogonal table-L₉（3⁴）was adopted to design the experiments,studying wear characteristics and behavior of three different formulations of PTFEcomposites under the impact-sliding coupling contact. Test results show that: lubricationstate changes affect the amount of wear on the material the most significant, and withoil lubrication or grease lubrication can greatly improve the wear of PTFE compositesin dry state friction; it has no direct relationship between the friction force and theamount of wear.By observing wear marks, the wear mechanism was analyzed and found thatlubrication state changes can dramatically affect wear mechanism changes. under dryfriction condition, wear is dominated by adhesive wear and flaking; under greaselubrication, wear is dominated by micro cutting and push-grinding; while under oillubrication, the specimen surface wear is not obvious, mainly in the fatigue wear based;defects for the friction and wear properties is enormous. Archard-based model was usedto calculate the amount of wear which shows that the wear condition is stable and theresults of texts exhibit good repeatability.