| The key technologies about tribometer where the chamber is filled with gas were proposed and the tribometer was developed for experiments with controlled gas pressure under different environment conditions by the support of national 973 project "Tribological Properties of Materials under the Effect of Strong Oxidants".The tribological behaviors of PTFE,modified PTFE and UHMWPE were investigated in different gases as well as the tribological behaviors of modified PTFE in H2O2.The surface morphologies,microstructure and elements of the pins were examined by virtue of automated 3D non-contact surface analysis,optical microscopy and electrochemical measurement system respectively.The results of this study could be summarized as follows.(1) The QK-1 controlled atmosphere tribometer was designed which was crucial to study the tribological performance of materials under atmosphere.The reliability of its performance was indicated by the reproducibility,comparability and sensitivity of the obtained data.In the development of the tribometer,some key technologies were resolved,such as corrosion resistance,sealing,transmission of the signal,loading and so on.The main functions and performance parameters are as follows.(â…°) The tribological experiments can be performed under the gas pressure of 0.2 MPa in bad gases or in the errosion liquid.(â…±) The error of the interior type gravity loading is less than 1.5%.The maximum normal loading is 100 N and the minimum normal loading is 10 N.(â…²) The adjustable rotational speed is controlled by the transducer.The maximum rotational speed is 2000 r/min.The error of rotational speed is less than 3%.The linear velocity ranges from 0.13 m/s to 5.2 m/s.(â…³) The friction coefficient can be obtained by an on-line real-time measurement system.(â…´) The contact forms of the pairs include block against ring(plane)-disc,pin against ring-disc and block(arc) against ring-disc.(2) The tribological characteristics of PTFE,modified PTFE and UHMWPE against 1Cr18Ni9Ti SS were investigated at pressure of 0.1MPa in the presence of N2,H2,O2,SO2 and Ar.The results showed that the friction coefficient were effected significantly by the atmosphere.The friction coefficient of pin in SO2 was higher.The wear resistance of modified PTFE which was equivalent with UHMWPE was improved enormously than that of PTFE.Due to the different activity of additive filled in the PTFEs in different gases,the difference among the abrasion of the pins were distinct.Adhesive wear were occurred at different degrees on the worn surface in N2,H2 and SO2.The worn surface with some abrasive dust was smooth relatively in O2 while the deep and wide furrows were presented in Ar.The surface roughness of pin which was unrelated to its wear loss was lower after testing.(3) The friction coefficient of six kinds of modified PTFE pins against 1Cr18Ni9Ti SS were low.The tribological performance of pins were obviously different owing to various fillings.The consistency of H2O2 had a little effect on the friction coefficient and wear loss of 5# pin.
|
PDF Full Text Request