Product properties I Mechanical behaviour and failure

Product (article) properties are in principle determined by combinations of intrinsic and added properties. However, the correlations between these basic properties and the (more or less subjectively defined) product properties are often complex and only partly understood. They are system-related . 

None of the mechanical product properties can be estimated directly from additive quantities. There exist, however, several quantitative relationships that connect the mechanical product properties with intrinsic mechanical properties. 

Product or article properties (also called end-use properties) are very complex. They depend not only on the material of which the product or article is made, but also - and mainly - on the system of which the article forms part product properties are system related . 

Friction, abrasion and wear, for instance, are - mathematically - operators of a system, i.e. they depend on the parameters of a system, such as the geometry of the surface, the temperature, the load, the relative velocities, the composition of the environmental atmosphere, etc. The operational character of wear, for example, depends on the physicochemical interaction of surfaces and on their interaction with the lubricant and the atmosphere. 

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