Fracture of Chip Mechanics Flashcards
What are the main chip types observed in metal cutting?
Continuous, continuous with a built-up edge, and discontinuous.
What is the shear angle in the context of chip formation?
It is the angle that defines the line along which plastic deformation occurs during chip formation.
Why do traditional analytical models often fail in metal cutting predictions?
They underestimate cutting forces and fail to fully incorporate fracture toughness and size effects.
What are intrinsic and extrinsic size effects in metal cutting?
Intrinsic effects relate to material properties, tribology, and fracture mechanics, while extrinsic effects include cutting tool geometry, surface roughness, and operational parameters.
What role does fracture toughness play in metal cutting?
It accounts for the work required to form new surfaces during cutting, which is significant in improving finite element analysis predictions.
What are the two main views on chip formation mechanics?
The traditional view emphasizes plastic flow and friction, while the alternative view includes significant contributions from surface formation energy.
What experimental methods are used to study stress-strain relationships in metal cutting?
Mechanical tests like impact tests, gas gun, and Hopkinson bar experiments.
What factors affect chip formation in metal cutting?
Material properties (e.g., ductility, hardness), cutting conditions, rake angle, and strain rate.
How does size reduction affect chip formation in micro-machining?
Smaller sizes emphasize surface effects, leading to increased specific cutting pressure and reduced ductility.
What are the challenges in finite element analysis (FEA) for metal cutting?
Incorporating accurate flow stresses, friction conditions, and coupling fracture toughness with plastic deformation models.
