Specialist Coatings and Lubrications

UNASIS XtrMD coating is a Molybdenum Disulphide (MoS2) based coating. It can be used on a wide variety of components.

MoS2 is a naturally mined inorganic material which has become very popular as a dry film lubricant. This is because of its price, availability and many advantages over other dry film lubricants. Through reducing the coefficient of friction, MoS2 increases speed capacity and bearing life by being a sacrificial lubricant. In ultra-high vacuum applications when bearings are going at high speed, the XtrMD coating could create a small particulate which may contaminate the vacuum. MoS2 coating can be applied to stainless steel hybrid bearings.

Tungsten Disulphide is heavier and more stable than Molybdenum Disulphide (MoS2), and has been used extensively throughout a variety of NASA, military and aerospace applications. With the ability to slow corrosion in some materials, and an even lower friction coefficient than MoS2, Tungsten Disulphide has been a popular coating for numerous high-end applications. It can help with issues like excessive wear, seizing, galling and fretting. The coating is only 0.5 micron thick, and does not bond to itself, avoiding build up. It is also inert, nonmagnetic and non-toxic, but unlike Molybdenum Disulphide it will not lead to particulate contamination of an ultra-high vacuum. Tungsten Disulphide can be used to coat both hybrid and standard bearings.

XtrChrome is a nodular thin dense chrome coating that is applied to the bearing components in a way that guarantees precise coating deposition. It has many advantages, such as corrosion resistance, increased surface hardness, cost reduction, increased bearing life, reduced production lead time and energy saving properties from the reduced surface friction.

XtrChrome is applied across a number of industries, such as aerospace, oil & gas, semiconductor, naval, chemical, pharmaceutical and food processing. It is useful as a coating for bearings in particular, and bearing surfaces made from 52100, M-50, M-50 NIL, BG-42. 440C, and all pH basis metals. XtrChrome allows bearing surfaces to run longer and

cooler. US Air force tests have revealed that XtrChrome enhances ball and roller bearings and does not impact or induce fatigue or change base metal features.

The surface texture gives excellent performance in extreme environments, particularly when combined with ceramic rolling elements. The nodular microscopic surface holds lubrication in the surface structure, creating advantages in environments like: fast acceleration without full ball loading, emergency rundown due to loss of lubrication, oscillating movements that don’t complete a full revolution, environments which do not allow for lubrication, and low rotational speeds. Speed capabilities at lower operating temperatures are increased significantly. Fretting corrosion caused by micro displacement of the bearing rings can be greatly reduced.

XtrChrome Coating Benefits:

• Increased wear resistance due to 78HRC surface hardness
• Corrosion resistance exceeding 440C stainless steel, with additional chemical resistance
• Reduced friction and wear in application
• Reduced maintenance and part replacement costs
• Complete adhesion to base metal: no chipping, flaking, cracking or peeling
• Reduced micro weld adhesion
• Increased running capabilities with lower coefficient of friction
• FDA approved for product contact
• Nodular surface gives improved adhesion strength of lubrication film
• XtrChrome coated components are more economic and readily available the 440C Stainless Steel

XtrPoly is a polymer which is injected and cured to seal the volume between the rolling elements and races inside a bearing. The polymer is filled with lubricant that is expelled under load. This gives a constant and consistent lubrication inside the bearing system. This also means there no need for additional lubrication during a XtrPoly filled bearing’s life.

Because XtrPoly is a solid, it helps block debris and reduce the introduction of foreign contamination into the bearing. Reducing the intrusion of debris into the bearing can greatly extend the its life. The solidness of XtrPoly also makes it suited for environments where grease and oil leakage can’t be endured, as it will not drip from the bearing and contaminate the environment.

XtrPoly filled bearings have lower speed limitations than standard oil or grease lubricated bearings.

Filling bearings with XtrPoly does not change their dimensional tolerances, it simply fills the spaces between the rolling elements and the cage. Any standard or nonstandard bearing may be filled.

Greases and Oils are lubricants put on to the majority of bearings as a way to decrease wear on rolling elements. They can be altered to meet the demands of various applications.

High temperature, high load or high-speed bearing applications would all require specialist lubricants, and all UNASIS hybrid bearings can be greased to suit these specific application requirements. Specialist lubrications can be used for ultra-high vacuum compatibility, radiation and chemical resistance along with food grade applications.  Please contact us for help in specifying your required lubrication. Grease and oil lubricants may be added to both full ceramic and hybrid bearings in order to change their performance characteristics, for example to increase speed, reduce ball skidding or reduce noise.