Transcript Fundamentals of Cutting & Cutting

Fundamentals of Cutting
&
Cutting-Tool Materials and
Cutting Fluids
CHAPTERS 20 & 21
OF
MANUFACTURING ENGINEERING
AND TECHNOLOGY
BY KALPAKJIAN
THIRD EDITION
MET127 - APPLIED MANUFACTURING PROCESSES I
Group Report by
Mark Cardin
Jim Chesko
Bob Pingarelli
Gary Thomas
&
Steve Stewart
Introduction
Cast, formed and shaped products
may need further machining
operations.
Machining processes remove material
from a workpiece.
• CUTTING:
• ABRASIVE:
• NONTRADITIONAL:
Fundamentals of Cutting
• Mechanics of Chip Formation.
– RAKE ANGLE
– RELIEF ANGLE
– SHEAR ANGLE
• Chip Type.
– CONTINUOUS
– BUILT-UP EDGE
– SERRATED
– DISCONTINUOUS.
Fundamentals of Cutting
• Oblique Cutting.
– THREE DIMENTIONAL
– INCLINATION ANGLE
• Cutting Forces and Power.
– MACHINE TOOL SELECTION
– DYNAMOMETER
– MANY VARIABLES
• FRICTION
• CUTTING FLUIDS
• TOOL SHARPNESS
• PROCESS
Fundamentals of Cutting
• Temperatures in Cutting.
– TOOL PROPERTIES
– DIMENSIONAL ACCURACY
• Tool Life.
– HIGH STRESSES & TEMPERATURES
– GRADUAL WEAR
– MANY VARIABLES
• MATERIAL
• CUTTING FLUIDS
• TOOL SHAPE
• SPEEDS & FEED RATE
– CHIPPING
Fundamentals of Cutting
• Surface Finish and Integrity
– GEOMETRY
– PROPERTIES
• FATIGUE LIFE
• CORROSION RESISTANCE
• Machinability
– RATINGS BASED ON TOOL LIFE
– DECREASES AS HARDNESS INCREASES
– ALLOYING ELEMENTS
Cutting Tool Materials and Cutting Fluids
• Cutting Tool Materials
• ARE SUBJECTED TO...
– HIGH TEMPERATURES
– CONTACT STRESSES
– ABRASION
• MUST HAVE...
–
–
–
–
HARDNESS
TOUGHNESS
WEAR RESISTANCE
CHEMICAL STABILITY
• Material Categories:
• CARBON AND MEDIUM
ALLOY STEELS
• HIGH-SPEED STEELS
• CAST-COLBALT ALLOYS
• CARBIDES
• COATED TOOLS
• ALUMINA-BASED CERAMICS
• CUBIC BORON NITRIDE
• SILICON-NITRIDE-BASED
CERAMICS
• DIAMOND
• WHISKER-REINFORCED
MATERIALS
Cutting Tool Materials and Cutting Fluids
• Cutting Fluids
– REDUCE FRICTION AND WEAR
– REDUCE ENERGY CONSUMPTION
– COOL THE CUTTING ZONE
– PROTECT MACHINED SURFACES
• Fluid Action
– CAPILLARY ACTION
– SMALL MOLECULAR SIZE
– PROPER WETTING CHARACTERISTICS
Cutting Tool Materials and Cutting Fluids
• Types of Cutting Fluids
– OILS
– EMULSIONS
– SEMI-SYNTHESIS
– SYNTHETICS
• Methods of Application
– FLOOD COOLING
– MIST COOLING
– HIGH PRESSURE REFRIGERATED SYSTEMS
Cutting Tool Materials and Cutting Fluids
• Effects of Cutting Fluids on…
– WORKPIECE MATERIALS
– MACHINE TOOLS
• Biological and Environmental Effects
– OPERATOR CONTACT
– EXTERNAL ENVIRONMENT
– DEGREDATION & CHEMICAL CHANGE
• Waste Management
– CLARIFICATION
– RECYCLING
– DISPOSAL