Техническая информация Sumitomo - страница 3

Technical Guidance
Turning Edition Tool Failures and Tool Life
■ Forms of Tool Failures
Cat. No. Name of Failure Cause of Failure
(1) to (5) Flank Wear Due to the scratching effect of hard grains contained in the work


Mechanical Causes
Resulting from
material.
(6) Chipping Fine breakages caused by high cutting loads or chattering.
(7) Fracture Large breakage caused by the impact of excessive mechanical forces
acting on the cutting edge.
(8) Crater Wear Swaft chips removing tool material as it flow over the top face at high


Chemical Reactions
Resulting from
temperatures.
(9) Plastic Deformation Cutting edge is depressed due to softening at high temperatures.
(10) Thermal Crack Fatigue from rapid, repeated heating and cooling cycles during machining.
(11) Built-up Edge Adhesion or accumulation of extremely-hard work material on the cutting edge.


■ Tool Wear
Forms of Tool Wear Flank Wear Crater Wear


Flank Wear Width KT (mm)
Flank Wear Width VB (mm)

Bad chip control
cutting edge fracture
Burrs occur Initial wear
Crater wear KT Sudden
increase
Poor surface finish Side flank wear in wear
Crater Wear
VN1 Steady wear
Face flank wear
VN2
Cutting Time T (min) Cutting Time T (min)
Flank average wear VB
Edge wear VC Flank Wear ・Wear increases rapidly right after cutting ・Wear increases in proportion to the
Higher cutting force starts, it then progresses at a moderate and cutting time.
Poor machining accuracy, proportionate pace up to a certain point
Burrs occur where it suddenly increases rapidly again.


■ Tool Life (V-T)
・This double logarithm graph shows the relative tool life of the specified wear over a range
of cutting speeds on the X-axis, and the cutting speed along the Y-axis.
Flank Wear Crater Wear
Crater Wear Depth
Flank Wear Width


vc1 vc2 vc3 vc1 vc2 vc3 vc4
vc4
Tool Wear


KT
(mm)


VB
(mm)


T1 T2 T3 T4 T'1 T'2 T'3 T'4
Cutting Time (min) Cutting Time (min)

Invc1
Cutting Speed


Cutting Speed


Invc1
Invc2 Invc2
(m/min)


(m/min)


Invc3 Invc3
Tool Life


Invc4 Invc4

InT1 InT2 InT3 InT4 InT'1 InT'2 InT'3 InT'4
Tool Life (min) Tool Life (min)

N
Technical Guidance /
References


N11