Page 32 - The Tribology Handbook

Dry rubbing bearings A5

MATER I A LS

Usually compa'sites based on polymers, carbons, and metals.

The properties of typical dry rubbing bearing materials

MU. Heat conductivity
Max. static load CO@
lypc Examplcs ttmp. CXP. Spccial features
MN/m2 lo3 Ibf/in2 "C 1061°C W/m"C Btu/ft h "F
Thermoplastics Nylon, acetal, 10 1.5 100 100 0.24 0.14 Inexpensive
UHMWPE
Thermoplastics Above+MoSz, 15-20 2-3 150 60-100 0.24 0.14 Solid lubricants
+fillas PTFE, glass, reduce friction
graphite, etc.

PTFE + fillen: Glass, bronze, 2-7 0.3-1 250 60-100 0.25- 0.15 Very low friction
mica, carbon, 0.5 0.3
metals

High tempera.ture Polyimides 30-80 4.5-12 250 20-50 0.3-0.7 0.2-0.4 Relatively
polymers (+fillers) polyamide-imide expensive
PEEK

Thermosets Phenolics, epoxies 30-50 4.5- 175 10-80 0.4 0.25 Reinforcing fibres
+fillers +asbestos, 7.5 improve
textiles, PTFE strength

Carbon- Varying graphite 1-3 0.15- 500 1.5-4 10-50 6-30 Chemically inert
graphite content; may 0.45
contain resin

With Cu, Ag, 3-5 0.45- 350 4-5 15-30 9-18 Strength increased
Carbon-metal Sb, Sn, Pb 0.75

Metal-solid Bronze-graphite 30-70 4.510 25CL 10-20 50-100 3 W High temperature
lubricant -MoS, ; Ag- 500 capability
PTFE

Special non- Porous bronze/ 350 50 275 20 42 24 Need to be
machinable PTFE/Pb considered at
products F'TFE/glass 700 100 250 12 0.24 0.14 the design
weave +resin stage
Thermoset+ 50 7.5 150 10 0.3 0.2
PTFE surface
Metal+ filled 7 1 7.75 100 0.3 0.2
PTFE liner

Notes :
Au values are approximate; properties of many materials are anisotropic.
Most materials are available in various forms: rod, sheet, tube, etc.
For more detailed information, consult the supplier, or ESDU Data Item 87007.
A5.1