Grinding (연삭) (1) g ( ) ( )

Ch t 9 M t i l R l Chapter 9. Material-Removal Processes: Abrasive, Chemical, Electrical, and High-Energy Beams

Sung-Hoon Ahn

School of Mechanical and Aerospace Engineering

Seoul National University

Grinding (연삭) (1) g ( ) ( )

ƒ Hardness

ƒ Friability (깨짐성) Friability (깨짐성)

ƒ

Self sharpening (자생작용)

ƒ

Grain fragments rapidly

ƒ Grain size (입도)

ƒ Grain size (입도)

ƒ

Grit number (입도지수)

ƒ

10>100>500

Grinding (연삭) (2) g ( ) ( )

ƒ Irregular geometry of grains.

ƒ Highly negative rake angle : -60° or even lower.g y g g

ƒ The radial positions of the grains in a grinding wheel vary.

ƒ High cutting speed : ~30m/sg g p

Ref.

S. Kalpakjian, "Manufacturing Processes for Engineering Materials", 3^rd/4^th ed. Addison Wesley

Residual stresses

Surface Grinding (평면연삭) g ( )

Ref.

S. Kalpakjian, "Manufacturing Processes for Engineering Materials", 3^rd/4^th ed. Addison Wesley

Cylindrical Grinding (원통연삭) y g ( )

Internal Grinding (내면연삭) g ( )

Ref.

S. Kalpakjian, "Manufacturing Processes for Engineering Materials", 3^rd/4^th ed. Addison Wesley

Centerless Grinding (무심연삭) g ( )

Ultrasonic Machining (초음파가공) g ( )

Ref.

S. Kalpakjian, "Manufacturing Processes for Engineering Materials", 3^rd/4^th ed. Addison Wesley

Finishing Operations (마무리공정) g ( )

ƒ Honing (호닝)

ƒ

Superfinishing

ƒ

Superfinishing

ƒ Lapping (래핑)

P li hi (연마) / B ffi (버핑)

ƒ Polishing (연마) / Buffing (버핑)

Lapping

Ref.

S. Kalpakjian, "Manufacturing Processes for Engineering Materials", 3^rd/4^th ed. Addison Wesley

Chemical Machining (화학적가공) g ( )

Electrochemical Machining / Grinding

ƒ ECM (전해가공) ƒ ECG (전해연삭)

Ref.

S. Kalpakjian, "Manufacturing Processes for Engineering Materials", 3^rd/4^th ed. Addison Wesley

Electro Discharge Machining (EDM)

ƒ EDM (방전가공 )

Micro ECM / EDM

Ref.: Prof. C. N. Chu

Wire EDM

ƒ Wire EDM (방전와이어 커팅)

Laser beam machining (LBM)

ƒ Light Amplification by Stimulated Emission of Radiation (LASER)

Ref.

S. Kalpakjian, "Manufacturing Processes for Engineering Materials", 3^rd/4^th ed. Addison Wesley

First Ruby Laser

1960, Theodore Maiman, USA

Applications of Laser

Cutting Heat treating Welding

Applications W orkpiece

materials Laser ty pe

Cutting Metal PCO₂, CW CO₂, Nd:Y AG, ruby

Table 9.5 General Applications of Laser in Manufacturing

Cutting Metal PCO₂, CW CO₂, Nd Y AG, ruby

Plastics CW CO₂

Ceramic PCO2

Drilling Metal PCO2, CW CO2, Nd:glass, ruby

Plastics Ex cimer

Markingg Metaleta PCO₂2, Nd:Y AG,

Plastics Ex cimer

Ceramic Ex cimer

Surface treatment Matal CW CO₂

W elding Matal PCO₂, CW CO₂, Nd:Y AG, Nd:glass, ruby

Electron Beam Machining

Focused Ion Beam System (1)

ƒ What is Focused Ion Beam ?

ƒ

Nanoscale Hybrid Fabrication ToolNanoscale Hybrid Fabrication Tool

• Sputtering

• Deposition

ƒ FIB Components

ƒ

Ion Gun (10^-7 torr)

• Liquid Metal Ion Source (LMIS) q ( )

ƒ

Ion Optical Column

• Electrostatic Lens

• Variable Aperture Variable Aperture

ƒ

Vacuum Chamber (10^-6 torr)

ƒ

Specimen Stage

• Eucentric Stage

ƒ

Gas Nozzle

• Carbon

• Platinum

• Tungsten Schematics of FIB System

Focused Ion Beam System (2)

ƒ Hybrid Fabrication Methods

Primary Ions Sputtered Particles (ions or neutrals)

Volatile Products

Precursor Molecules

Sputtering (Milling) Deposition

Molecules

p g ( g) p

Case study: Stent

Ref.

S. Kalpakjian, "Manufacturing Processes for Engineering Materials", 3^rd/4^th ed. Addison Wesley