Metrology 4 Flashcards
What can improved surface finishing lead to?
Fatigue resistance
Bearing properties
interchangeability
wear resistance
What is the fatigue life of a component?
The number of stress reversals that a component can withstand
Where does failure due to fatigue usually occur?
Sharp corner or defect
How does surface area affect wear?
The rate of wear is dependant on the surface area. larger surface are, lower the load per unit area and therefore less wear
When did surface texture measurement instrumentation come commonplace?
After 1945
What is roughness?
The irregularities in the surface texture arise from the inherent action of the cutting process.
What is waviness?
The irregularities are caused mainly due to machine vibration and deflections under cutting force
Errors of from
The departure from the geometrical shape
What is the purpose of the skid in surface measurement?
to provide the probe a datum from which to measure change
which ISO specifies the magnification and filters?
ISO 16610
What implications help improve surface texture measurement?
Multiple sampling lengths - usually 5
Maintain standard sampling length for consistency
Take several traces at different positions on the work piece
What are the categories for surface texture parameters?
Based on the whole curve
Based on the magnitude of certain features
Based on the spacing between certain features
What are the standard roughness parameters?
Ra and Rq
What are Rp and Rv?
Maximum peak height and maximum valley depth
What is Rz?
maximum peak to valley height
