Chapter 21 - Chapter 21: 1-6 Mitchell Crow Introduction...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Click to edit Master subtitle style 5/8/09 Chapter 21: 1-6 Mitchell Crow
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
5/8/09 Introduction Cutting-Tool Materials Tool Geometry Tool Coating Processes Tool Failure and Tool Life Flank Wear - Reconditioning Cutting Tools
Background image of page 2
5/8/09 Tool Steel Carbon steels and low-/medium alloy steels. Used to be very common. When hardened and tempered has good hardness and strength and decent toughness and can carry a sharp edge. Lose hardness at temperatures above 400 degrees. Has been largely replaced by other materials for metal cutting. Still used for drills, taps, dies, reamers, broaches, and chasers.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
5/8/09 High-Speed Steels (HSS) High-alloy steel. Keeps its cutting ability at temperatures up to 1100 degrees. Can operate at 2X or 3X the cutting speed with the same life span as tool steel. Typical composition is 18% tungsten, 4% chromium, and 1% vanadium. Used for drills, general-purpose milling cutters, and in single-point tools in machining (metal lathes, shapers, planers, etc.). In high-production machining it has been replaced by carbides, coated carbides and
Background image of page 4
5/8/09 Pros Great toughness Easily fabricated Best for sever applications where complex tool geometry is needed (taps, drills, reamers, dies). Cons Improper processing of cast and wrought products can result in/ cause wide fluctuation of properties, inconsistent tool performance, distortion and cracking. To fix this they can use a powder metallurgy technique but it is about double the cost of regular
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
5/8/09
Background image of page 6
TiN-Coated High-Speed Steels HSS coated in titanium nitride. Used for gear cutters, drills, broaches, bandsaw, etc. Coated using physical vapor deposition (PVD). Pros Reduced tool wear. High hardness. Greater tool life through reduction in adhesion. Low coefficient of friction which increases shear angle. Cons Vigorous cleaning process before coating (degreasing, ultrasonic cleaning, Freon drying). Failures in high-stress
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 28

Chapter 21 - Chapter 21: 1-6 Mitchell Crow Introduction...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online