Lubrication of polycarbonate at cryogenic temperatures in the split Hopkinson pressure bar

✍ Scribed by A. Trautmann; C.R. Siviour; S.M. Walley; J.E. Field

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 660 KB
• Volume: 31
• Category: Article
• ISSN: 0734-743X
• DOI: 10.1016/j.ijimpeng.2004.02.007

✦ Synopsis

The dynamic friction behaviour of polycarbonate (PC) was investigated at ambient ð26 CÞ and low temperature ðÀ60 CÞ using a split Hopkinson pressure bar (SHPB) and specimens of varying thicknesses. At ambient temperature, polytetrafluoroethylene (PTFE) and molybdenum disulphide ðMoS 2 Þ were found to be good lubricants, but not as good as petroleum jelly, which reduced friction to zero (within experimental error). In the low-temperature regime, PTFE was not a good lubricant. MoS 2 was not as good a lubricant as ice at À60 C: However, again petroleum jelly provided perfect lubrication within experimental error. This was confirmed by a ring upsetting test in a drop-weight apparatus using high-speed photography. The PC used had a glass transition temperature T g of 422 K as determined by differential scanning calorimetry (DSC). The intrinsic (zero friction) yield stress of PC in compression at a strain rate of 25007200 s À1 was found to be 110 MPa at a strain of around 0.1 at 26 C and 175 MPa at a strain of approximately 0.