Tribologie M

Marine diesel engine oils
Various marine diesel engine oils are used for ships that sail on the high seas. The type depends on the engine type, engine speed, operation and fuel:

a) Engine oils in accordance with API CD can be used for stationary diesel engines and fast-running trunk piston diesel engines and for operation with diesel fuel.

b) Marine diesel engine oils with very good detergent-dispersant characteristics and good thermal and oxidative resistance should be used for trunk piston diesel engines that run at medium speeds and use residual heavy oil for fuel.

c) Only highly alkaline marine diesel engine oils with very good dispersive and neutralizing properties should be used to lubricate cylinders on crosshead engines that also use residual heavy oil for fuel.
 

Metal deactivators/passivators 
Dialkylzinc dithiophosphates; metal phenates; organic nitrogen and sulphur compounds, amines, benzotriazoles, derivates, certain soaps, etc. The effect is based on the formation of surface films so that metal surfaces cannot induce oil oxidation catalytically.
 

Metal soaps
Metals and their compounds react with fatty acids and form metallic soaps; these are used as EP additives in lubricating oils and as thickening agents in lubricating greases.
 

Metalworking oils
Collective term for cutting oils, rolling oils, drawing oils and drilling oils, both water-miscible and non-water-miscible; standard term is coolant. Their main tasks depend on the application: lubrication, cooling, transportation of swarf, corrosion protection, etc. (See coolants.)
 

Methane – CH4
First molecule of the paraffinic (alkane) family of hydrocarbons; main component of natural gas; also contained in refinery gas, coal gas, etc.
 

MIL specifications
Specifications of the US military with minimum requirements for the operating supplies they purchase; some engine and machine manufacturers specify the same minimum requirements,
i.e. in accordance with MIL specifications; compliance with minimum requirements is considered to be a quality standard.
 

Mineral oils
Mineral oils and mineral oil products are liquid distillation and refinery products obtained from petroleum, a mineral-based raw material, and which primarily consist of mixtures of saturated and possibly very small amounts of unsaturated hydrocarbons.
 

Mixed friction
Is a friction situation where boundary friction and viscous friction occur together/
in sequence. Surface roughness (roughness points) are sometimes separated but sometimes contact is made so that wear occurs.
 

Molybdenum disulphide (MoS2)
This is a solid lubricant with a layer lattice structure. If it is properly worked into the metal surface, this solid body with a lamellar structure can reduce the coefficient of friction of the surface for a period of time. It is often use as an additive mixed in with lubricating oils, lubricating greases, compounds, etc.
 

MOULD OILS
a) Moulds made of wood, metal or similar material for the manufacture of concrete, ceramics, pantiles, etc. are lubricated with thin oils or emulsions for effective release of the moulded parts.

b) Core oils for mixing with moulding sand.

Multi-grade engine and gear oils
These are lubricating oils which are intended for use in vehicles all the year round thanks to their very good viscosity temperature characteristics. They cover several SAE classes, for multi-grade engine oils:
5W-30, 10W-30, 5W-40, 15W-50, etc.,
VI approx. 130 to 170. For multi-grade gear oils: 75W-90, 80W-90, 85W-140, etc.,
VI approx. 115 to 170.

Multi-grade oils
These are industrial lubricants which use special additives to meet the requirements of various machine tools units. They can therefore be used as gear oils, slide oils, cutting oils, etc.