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TOOL WEAR &

TOOL LIFE

By Ankit nayakVikram singh

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DEFINED AS- It may be the actual cutting time before failure . Volume of work material removed before the

failure. Number of component produced before failure. The cutting speed at which it is removing the

material for specified time . The length of material removed before the failure.

TOOL LIFE

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VTn = C

WhereV= Cutting speed (m/min)T= Time (min)n = Exponent depends on tool material c = constant biased on tool and work material and cutting condition

TAYLOR’S TOOL LIFE EQUATION

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v= cutting speed t= tool life 1= HSS

2=Carbide3=Ceramic

Log V

log t ©

TOOL LIFE CURVE

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2

1

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n = 0.08 to 0.2 for HSS tool=0.1 to 0.15 for cast alloy=0.2 to 0.4 for carbide tool=0.5 to 0.7 for ceramic tool

VALUES OF EXPONENT ‘n’

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VTnfadb = CWhere: d = depth of cut f = feed rate OR

1/n > 1/m > 1/p

EXTENDED ORMODIFIED TALYLOR’S EQUATION

Reduction in Tool Life30-7

Operating Conditions

CUTTINGSPEED + 50%

FEEDRATE + 50%

DEPTH OFCUT + 50%

90% 60% 15%

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Cutting speed . Tool geometry. Tool material. Work material. Coolants.

Factors Affecting the Life of a Cutting Tool

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A device with one or more edges used to create chips and remove metal. Cutting tools are either single point or multi-point tools.

CUTTING TOOL

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R&D LAB

Total breakage of cutting tool or tool tip

Excessive rise in cutting forces and vibrations

Flank and crater wear reach their limit

CONDITION DESIDING FOR TOOL FAILURE

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Mechanical breakage. Plastic deformation. Gradual wear.

1. Crater wear2. Flank wear

FAILURE OF CUTTING TOOL&

TOOL WEAR

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It occur on Flank Surface RESIONS-* Abrasion by hard particles.* Shearing of micro weld between tool and

work material.* At low speed flank wear predominate.* If MRR increase flank wear increase.

FLANK WEAR

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EFFECT-* Flank wear directly affect the component

dimension.* Decrease tool life.* Rough surface finish.

FLANK WEAR

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Primary wear Secondary wear Tertiary wear

FLANK WEAR

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FLANK WEAR

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Crater wear occurs on the rack surface . More common in ductile materials which

produce continuous chip. At very high speed crater wear pre-

dominates.

CRATER WEAR

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Crater wear linear increase with time. It increase with MRR. Crater wear has little effect on work piece

tolerance or surface finish.

CRATER WEAR

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C. W.

time

CRATER WEAR

MRR increasing

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Crater Wear and Flank Wear

Crater wear

Flank wear

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Abrasion wear Adhesion wear Diffusion wear

WEAR MECHANISM

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Manufacturing science by GOSH & MALLIK . Production engg. and Science by PANDAY &

SINGH. Production engg. By SWADESH KUMAR. Metal cutting by A. BHATTACHARYYA. web.iitd.ac.in/~suniljha/MEL120/Tool

%20Life2012.pdf nptel.iitm.ac.in/courses/Webcourse-

contents/.../pdf/LM-14.pdf

REFRANCES

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Presented by

ANKIT NAYAKankitnayak@live.com

&VIKRAM SINGHvikram.mech89@gmail.com

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Thanks