Mechanics of metal cutting Flashcards
What are the 4 basic types of chip in machining?
-Discontinuous chip
-Continuos chip
-Continuos chip with built up edge
-Serrated chip
What are the characteristics of a discontinuous chip?
-Brittle
-Low cutting speeds
-Large feed & depth of cut
-High tool-chip friction
What are the characteristics of a continuous chip?
-Ductile
-high cutting speed
-small feed & depth
-sharp cutting edge
-low tool-chip friction
What are the characteristics of a continuos chip with BUE(Built up edge)
-Ductile
-low to medium cutting speed
-BUE forms then breaks off
What are the characteristics of a serrated chip?
-Saw tooth appearance
-difficult to machine metals at high speed
What is chip entanglement?
Tangling around the tool, need to be cleared away.
discontinuous chips don’t entangle
What is chip curling?
Curling of chips that break away naturally
What is a chip breaker?
Prevent loss of productivity due to entanglement.
most inserts come with built-in chip breaker features.
What is dry Machining?
No cutting fluid is used.
Means no filtration or disposal is needed.
What are the disadvantages of dry machining?
-Overheating tool
-Lower cutting speed to ensure tool life is prolonged.
What are cutting fluids?
Used to reduce friction in cutting.
Also:
Wash away chips
reduce temp
improve stability of piece
What are the two classifications of cutting fluids?
Coolents - reduce heat
lubricants - reduce friction
What are the two applications of cutting fluids?
-Flood coolant delivery system - inefficient way of using cutting fluids
-Minimum quantity lubrication systems - uses the minimum to make cutting fluid effective.
What is oil mist?
A method of reducing friction by creating a mist with the cutting fluid.
Disadvantages of Oil mist?
-Breathing problems in workplace.
-eye irritation
