Bodycote Hot Isostatic Pressing

Low Friction and Extended Wear Life For Fiber-Contact Surfaces

TECH 40 is a composite ceramic material thermochemically bonded to customer specified areas of fiber-contact surfaces of various fiber processing equipment, including godet rolls, separator rolls, pins, and pig-tail guides. Individual sub-micron sized ceramic particles of the ceramic matrix lock together with 15 micron-sized particles of chromium oxide. Applied in slurry form, through spraying or dipping, and porous after the initial formation of the ceramic, TECH 40 is densified using ceramic precursor chemicals plus corrosion resisting chemicals. When thermochemically converted into ceramic and corrosion protection in situ, the densification processes form additional bonds and mass within the initial ceramic body. Each densification cycle fills some of the remaining porosity until a fully dense, non-porous, corrosion resistant, ceramic coating has been created.

BOND STRENGTH
TECH 40 develops a bond into the substrate through the formation of a spinel-like interphase between the ceramic coating and the metal surface. Part of the thermochemical reaction causes the substrate metal atoms to migrate into the ceramic coating during initial processing. Like the Tech 22 coating, TECH 40's bond strength to the substrate is in excess of 10.000 PSI. TECH 40 develops a bond into the substrate through the formation of a spinel-like interphase between the ceramic coating and the metal surface. Part of the thermochemical reaction causes the substrate metal atoms to migrate into the ceramic coating during initial processing. Like the Tech 22 coating, TECH 40's bond strength to the substrate is in excess of 10.000 PSI.

DENSITY
TECH 40 is an almost totally dense (98~c) ceramic coating and is unique in that it has no open porosity. TECH 40 processing completely seals off this open porosity making the part impervious to chemical attack.

HARDNESS
As with Tech 22, the TECH 40 coating particle hardness range measures from 1000 to 2850 Vickers. In sliding wear applications the surface wears as a result of the hardest component, chromium oxide, which has a hardness of 2850 Vickers.

RESULTS
The unique combination of particle hardness, chemical bonding, and lack of porosity, and inherent low friction result in a coating which is unparalleled in wear resistance and fiber friendliness in fiber-contact applications. Abrasive yarns run over TECH 40-coated components for years without experiencing fraying. Life expectancy of parts used in these applications are now measured in years instead of weeks.

.002 - .004" thick

Hardness range 1000-1850 Vickers

Chemically Bonded

Extremely wear resistant

Resistant to thermal cycling & Shock

Fiber-friendly “orange-peel” as-applied surface

Surface finish adjustable from 5 - 60 Rms

Low friction

Polished surfaces will not abrade bushings and seals

Better resistance to corrosives

TECHNICAL DATA

HARDNESS
1000 - 1850 vickers

BOND MECHANISM
Chemical

BOND STRENGTH
Over 10,000 psi

THICKNESS
.0002-.0004 inches, typical

CORROSION RESISTANCE
+560 hrs in hot CaCl2 (no damage)

COEFFICIENT OF FRICTION
.20-.21 against fiber
.1-.13 against metal

Tech 40 Ceramic