- published: 13 Jun 2015
- views: 826472
Wear is related to interactions between surfaces and specifically the removal and deformation of material on a surface as a result of mechanical action of the opposite surface.
In materials science, wear is erosion or sideways displacement of material from its "derivative" and original position on a solid surface performed by the action of another surface.
Wear of metals occurs by the plastic displacement of surface and near-surface material and by the detachment of particles that form wear debris. This process may occur by contact with other metals, nonmetallic solids, flowing liquids, or solid particles or liquid droplets entrained in flowing gasses.
Wear can also be defined as a process where interaction between two surfaces or bounding faces of solids within the working environment results in dimensional loss of one solid, with or without any actual decoupling and loss of material. Aspects of the working environment which affect wear include loads and features such as unidirectional sliding, reciprocating, rolling, and impact loads, speed, temperature, but also different types of counter-bodies such as solid, liquid or gas and type of contact ranging between single phase or multiphase, in which the last multiphase may combine liquid with solid particles and gas bubbles.
So light is her footfall
She walks like a bird
She's an angel
Such a familiar stranger
I wish I could help her
She's in danger
She's all alone alone alone alone alone alone
All alone alone alone alone
So light is her footfall
She moves like a ghost
And I lost her
In the mist of dawn
She's already gone
And I miss her
She's all alone alone alone alone alone alone
All alone alone alone alone
And I miss her
And I miss her
She's all alone alone alone alone alone alone
All alone alone alone alone
So light was her footfall
So light was her footfall
So light was her footfall