BACHELOR OF ENGINEERING

MANUFACTURING TECHNOLOGIES

MACHINING FUNDAMENTALS

by Endika Gandarias

2 by Endika Gandarias

Dr. ENDIKA GANDARIAS MINTEGI Mechanical and Manufacturing department Mondragon Unibertsitatea - www.mondragon.edu (Basque Country) www.linkedin.com/in/endika-gandarias-mintegi-91174653

Further presentations: www.symbaloo.com/mix/manufacturingtechnology

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CONTENTS BIBLIOGRAPHY CHIP FORMATION CUTTING TEMPERATURES CUTTING FORCES AND POWER GLOSSARY

by Endika Gandarias

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BIBLIOGRAPHY

BIBLIOGRAPHY

by Endika Gandarias

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The author would like to thank all the bibliographic references and videos that

have contributed to the elaboration of these presentations.

For bibliographic references, please refer to:

• http://www.slideshare.net/endika55/bibliography-71763364 (PDF file)

• http://www.slideshare.net/endika55/bibliography-71763366 (PPT file)

For videos, please refer to:

• www.symbaloo.com/mix/manufacturingtechnology

BIBLIOGRAPHY

by Endika Gandarias

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CHIP FORMATION

CHIP FORMATION

by Endika Gandarias

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Oblique cutting Orthogonal cutting

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CHIP FORMATION

VIDEO

Faxial

Fradial

Faxial

λ

λ = 0º λ ≠ 0º

Introduction

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CHIP FORMATION

More realistic view of chip formation, showing shear zone rather than shear plane.

t0 : depth of cut (mm) tc : chip thickness (mm)

Orthogonal cutting model

VIDEO VIDEO

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CHIP FORMATION

by Endika Gandarias

λ

λ

λ = 0º

λ = 15º

λ = 30º

Oblique cutting model

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VIDEO

by Endika Gandarias

CHIP FORMATION

Discontinuous chip Continuous chip Continuous chip with Built-Up Edge

Serrated or segmented chip

VIDEO VIDEO VIDEO VIDEO

It depends on: Workpiece material Tool geometry Cutting conditions

Chip formation types

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CHIP FORMATION

Chip formation types

Chip formation and cutting temperatures in different workpiece materials:

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CUTTING TEMPERATURES

CUTTING TEMPERATURES

by Endika Gandarias

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CUTTING TEMPERATURES

The maximum heat generated during cutting is close to the cutting edge, in the chip breaker. This is where the maximum pressure from the material is, and, with the friction between chip and carbide, causes these high temperatures.

Severe temperature gradients within the tool and the chip occurs, and the workpiece remains relatively cool. Heat distribution is: 80% through the chip. 10% through the workpiece. 10% through the tool.

VIDEO

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CUTTING FORCES & POWER

CUTTING FORCES & POWER

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N = spindle speed (rpm)

Davg = average diameter (mm) Davg = (D0-Df)/2

Vc = cutting speed (m/min)

fn = feed per revolution (mm/rev)

ap = radial cutting depth (mm)

Kc = specific cutting force (N/mm2)

ηm = machine efficiency (0.7-0.8)

Fc = cutting force (N)

Pc = net power (kW)

Pc = Fc × Vc

60 × 103 × ηm

N

CUTTING FORCES & POWER

Fc = kc × ap × fn

[kW]

[N]

TURNING

Q = Vc × ap × fn [cm3/min]

by Endika Gandarias

Mc = Fc × Davg

2 [N*m]

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CUTTING FORCES & POWER

TURNING

by Endika Gandarias

N = spindle speed (rpm)

F = feed rate (mm/min)

Fc = cutting force (N)

Ft = thrust or feed force (N)

Fr = radial force (N)

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CUTTING FORCES & POWER

TURNING

EXERCISE: An external turning operation is accomplished for a 60mm rod steel CMC02.1 material using Vc=400 m/min. Calculate for the following 2 cases:

by Endika Gandarias

Fc ? [N] Pc ? [kW] Q ? [cm3/min] Mc ? [N*m]

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ap = axial cutting depth (mm)

D = tool diameter (mm)

ae = radial cutting depth (mm)

F = feed per minute (mm/min)

kc = specific cutting force (N/mm2)

Fc = cutting force (N)

Pc = net power (kW)

Q = metal removal rate (cm3/min)

CUTTING FORCES & POWER

MILLING

Pc = Fc × F

60 × 106

Fc = kc × ap × ae

[kW]

[N]

Q = ap × ae × F

1000 [cm3/min]

by Endika Gandarias

Mc = Pc × 30 × 103

π × N [N*m]

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Dc = 125 mm ap = 5 mm ae = 100 mm F = 600 mm/min

EXERCISE: A face milling operation is accomplished for a CMC 02.1 material. It is known:

CUTTING FORCES & POWER

MILLING

Fc ? [N] Q ? [cm3/min] Pc ? [kW] Mc? [Nm]

by Endika Gandarias

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fn = feed per revolution (mm/rev)

vc = cutting speed (m/min)

Dc = drill diameter (mm)

κr = positioning angle (º)

kc = specific cutting force (N/mm2)

Ff = feed force (N)

Pc = net power (kW)

Q = Metal removal rate (cm3/min)

CUTTING FORCES & POWER

DRILLING

Ff ≈

[kW]

[N]

Q = Dc × fn × Vc

4 [cm3/min]

Pc = kc × Dc × fn × Vc

240 × 103

kc × Dc × fn× sen κr

4

by Endika Gandarias

Mc = Pc × 30 × 103

π × N [N*m]

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CUTTING FORCES & POWER

DRILLING

Dc = 12 mm fn = 0,21 mm/rev κr = 59º Vc = 105 m/min

EXERCISE: A drilling operation is accomplished for a CMC 06.1 material. It is known:

Ff ? [N] Pc ? [kW] Q ? [cm3/min]

by Endika Gandarias

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GLOSSARY

GLOSSARY

by Endika Gandarias

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GLOSSARY

by Endika Gandarias

ENGLISH SPANISH BASQUE

Alloy Aleación Aleazio Axial cutting depth Profundidad de pasada axial Sakontze sakonera Built-up edge Filo de aportación Ekarpen sorbatz Chip Viruta Txirbil Chip breaker Rompe virutas Txirbil hauslea Continuous chip Viruta continua Txirbil jarraia Continuous chip with built-up edge Viruta continua con filo de aportación Txirbil jarraiko ekarpen sorbatz Cool Fresco Hozkirri / Fresko Cutting speed Velocidad de corte Ebaketa abiadura Discontinuous chip Viruta discontinua Txirbil ez jarraia Drilling Taladrado Zulaketa Engagement Empañe Lausotua Feed per revolution Avance por vuelta Aitzinamendua birako Feed per tooth Avance por diente Aitzinamendua hortzeko Feed rate Avance por minuto Aitzinamendua minutuko Flank Flanco / Lateral Albo Hardness Dureza Gogortasuna Milling Fresado Fresaketa Net power Potencia neta Potentzi garbia Oblique cutting Corte oblicuo Ebaketa zeihar Orthogonal cutting Corte ortogonal Ebaketa ortogonala Positioning angle Ángulo de posicionamiento Posizionamendu angelu Power Potencia Potentzia Radial cutting depth Profundidad de pasada radial / ancho de pasada Iraganaldi zabalera Rake Desprendimiento Jaulkitze Removal rate Tasa de eliminación Eliminazio tasa Rod Barra Barra Serrated or segmented chip Viruta escalonada o segmentada Txirbil mailakatu edo segmentatua

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GLOSSARY

by Endika Gandarias

ENGLISH SPANISH BASQUE

Shear strain zone Zona de deformación por cizalladura Ebakidura bidezko deformazio gunea Shearing Cizallamiento Ebakidura / Zizailadura Specific cutting force Fuerza de corte específico Ebaketa indar espezifikoa Spindle Cabezal Buru Spindle speed Velocidad de giro Biraketa abiadura Steel Acero Altzairu Thickness Espesor Lodiera Thrust Empuje Bultzada Tool Herramienta Erraminta Turning Torneado Torneaketa Wear Desgaste Higadura Workpiece Pieza Pieza