The Lathe: Types of Chip Formation & Chip Breaker Flashcards
What does the type of chip produced depend on?
The type of chip produced depends on the material being machined and the cutting conditions at the time.
Name some of the conditions that affect the chip produced
These conditions include the type of tool used, rate of cutting, condition of the machine and the use or absence of a cutting fluid.
What does continuous chip look like?
This leaves the tool as a long ribbon
Continuous chip is commonly produced when cutting what materials?
It is common when cutting most ductile materials such as mild steel, plastic, copper and Aluminium.
How do you get continuous chip?
It is associated with good tool angles, correct speeds and feeds, and the use of cutting fluid.
What does discontinuous chip look like?
The chip leaves the tool as small segments of metal
Discontinuous chip is commonly produced when cutting what materials with what type of rake angles?
resulted from cutting brittle metals such as cast iron and cast brass with tools having small rake angles. There is nothing wrong with this type of chip in these circumstances.
How is continuous chip with built-up edge caused?
This is a chip to be avoided and is caused by small particles from the workpiece coming welded to the tool face under high pressure and heat.
What does continuous chip with built-up edge result in?
The phenomenon results in a poor finish and damage to the tool.
How is continuous chip with built-up minimised or prevented?
It can be minimised or prevented by using light cuts at higher speeds with an appropriate cutting lubricant.
What are the disadvantages of continuous chip and how can this be solved?
A disadvantage is that they can become very long and become entangled with the machine or pose a safety hazard.
This problem can be overcome by the use of chip-breakers; a device clamped to the top of the tool that encourages the chip to curl more tightly, hitting the workpiece and breaking off
What is a chip-breaker?
a device clamped to the top of the tool that encourages the chip to curl more tightly, hitting the workpiece and breaking off
