Quiz 1 (Manufacturing Processes)

Front 1

The basic mechanism for chip formation is by shearing.

[TRUE or FALSE]?

Back 1

TRUE

Front 2

A built-up edge (BUE) consists in layers of material from the workpiece that gradually are deposited on the tool tip.

[TRUE or FALSE]?

Back 2

TRUE

Front 3

The tendency for BUE formation can be reduce by the following means:

Back 3

Increase the rake angle

Front 4

Grooves in the cutting tools cannot act as chip breakers

[TRUE or FALSE]?

Back 4

FALSE

Front 5

Using Taylor for tool life and letting n=0.5 and C=400, calculate the percentage of the increase in tool life when the cutting speed is reduced by 50%

Back 5

300%

Front 6

Metal Carbides are harder than Ceramics

[TRUE or FALSE]?

Back 6

FALSE

Front 7

For machining steel and cast iron, the diamond is the recommended tool.

[TRUE or FALSE]?

Back 7

FALSE

Front 8

A machining operation is being carried out with a cutting fluid that is an effective lubricant. What will be changes in the mechanics of the cutting operation if the fluid is shut off?

Back 8

The chip will become thicker

Front 9

Diamond tools work very well at high temperature (higher than 1000 Celsius)

[TRUE or FALSE]?

Back 9

FALSE

Front 10

Assume that, in orthogonal cutting, the rake angle is 15 and the coefficient of friction is 0.2. Using the equations:
to/tc=sin/cos(-α);
=45°+ α/2 - ß/2; µ=tan ß

Back 10

>> 16%


α = rake angle
 = shear angle
ß = friction angle
µ = coefficient of friction
t0 = depth of cut
tc = chip thickness
to/ tc = cutting ratio or chip-thickness ratio

α = 15°
 = 45° + 15/2 – 11.3099/2
= 46.85°
to/ tc =sin (46.85)/cos (46.85-15)
= 86%
to/ tc =sin (41.6)/cos (41.6-15)
= 74%
(0.2) = ß
11.3099 = ß

2 µ = tan ß
(0.2) = ß
21.8° = ß
 = 41.6°