Reduced mechanical friction wear
+30% performance under high loads

Frictional wear represents the progressive and continuous loss of material from solid surfaces, in reciprocal movement and contact, due to mechanical causes.

Any mechanical device without a uniform lubricating film suffers a loss of material over time, a phenomenon commonly referred to as frictional mechanical wear.

The functionality of the mechanical component is also quickly compromised if the grease or lubricating oil with wich it is equipped does not properly separate the friction surfaces under all working conditions.

Friction is the force that opposes the movement of two bodies in mutual contact. It is divided into static and dynamic, internal and external friction, where:

• Static is when the opposing friction force (Fr) is greater than or equal to the driving force (Fa)
  
  
• Dynamic is when the opposing friction force (Fr) is less than the driving force (Fa)
  
  
• External is either sliding or rolling, as the medium through which wear occurs and represents the force that prevents (static friction) or hinders (dynamic friction) movement, with its value related to the amount of microscopic contact created between adherent surfaces causing material deformation and grooves
  
  
• Internal is caused by the turbulence between the molecules of the lubricating film interposed between the contacting materials, also referred to as viscosity, and is one of the most important variables for the proper formulation of a lubricating oil or grease.

Mechanical wear is the result of a friction process. There are various ways through which it is accomplished, some of which can be combined and result in joint and destructive actions of:

• Abrasion > the formation of surface grooves due to the difference in hardness of the partners in friction
  
  
• Adhesion > the removal of surface material as a result of the tendency of two materials to stick together, distinguished between superficial and deep, depending on the extent of the process, where for superficial adhesion, the first molecular layers (oxides) are involved whilst for deep adhesion, a process of friction melting, tearing and breaking of the base materials is generated
  
  
• Surface fatigue > a loss of material and deformation of surfaces due to repeated mechanical stress (such as rolling components in rolling bearings)
  
  
• Erosion > formation of surface furrows caused by the impact of solid particles contained in colliding fluids at high speed
  
  
• Rubbing > localised wear on surfaces in contact due to mutual sliding caused by vibration
  
  
• Corrosion > removal of oxidised material from friction surfaces
  
  
• Electro-corrosion > removal of materials by dissolution in a corrosive liquid with the aid of electric current
  
  
• Electrical discharge > loss of material caused by removal of molten metal parts altered by electrical discharge

Loss of material in the form of mechanical wear and tear is inevitable in any friction process. Its occurrence can be minimised through targeted lubrication in tune with operating conditions to prevent premature malfunctioning of the mechanical kinematics involved.

The choice of a suitable grease or lubricating oil passes through the analysis of the tribosystem, being the set of conditions and variables that affect the immediate surroundings of a friction process.

What are the components involved in the analysis of a tribosystem?

• Structure – chemical composition of materials in friction, metals, plastics, elastomers, their surface roughness
• Operating parameters – working load, specific pressures, flow speed and operating temperature
• Interaction parameters – the type of friction (rolling or sliding), the friction condition (boundary, mixed, fluid), presence of contaminants or process fluids (such as powders, acids or bases) and lubricating oils or greases
• Tribometric parameters – coefficient of friction and material lost through friction

Only through a proper analysis of the tribosystem can the most suitable lubricant composition chosen.