exam questions

Question 1

4 types of chip

Answer 1

continuos
build up edge
serratted (semi continous)
non countinous

Question 2

problem caused by cointinous chips and solution

Answer 2

Problem: The continuous chips tangle around a tool holder, fixture, and operations need to be halted to remove the chips.
Solution: Use a chip breaker OR change a machining parameter, (such as cutting speed, feed, cutting fluids)

Question 3

describe what adhesive wear is. How does adhesive wear damage the cutting tool?

Answer 3

Adhesive wear occurs when material from the work-piece forms a micro-weld with the cutting tool.
When the micro-weld breaks off, it takes part of the tool with it.
look at diagram

Question 4

, describe what abrasive wear is. State clearly how abrasive wear damages the tool

Answer 4

Abrasive wear is caused by a hard and rough surface that slides across another surface. Abrasive wear occurs when parts of the tool are removed through use.

Question 5

In machining, what happens if the thrust force is too high?

Answer 5

If thrust force is too high, the cutting tool will be pushed away from the surface of the workpiece.

Question 6

how can you reduce the tool being pushed away from the worksurface

Answer 6

reduce the cut depth

Question 7

speed increases by 50% what does tool life do

Answer 7

dont lknow
https://vle.shef.ac.uk/bbcswebdav/pid-3175261-dt-content-rid-9111547_1/courses/MEC130.A.180071/MEC130%20Formatted%2013.4.16.pdf a4a

Question 8

feedincreases by 50% what does tool life do

Answer 8

dont lknow
https://vle.shef.ac.uk/bbcswebdav/pid-3175261-dt-content-rid-9111547_1/courses/MEC130.A.180071/MEC130%20Formatted%2013.4.16.pdf a4a

Question 9

depth of cut increases by 50% what does tool life do

Answer 9

dont lknow
https://vle.shef.ac.uk/bbcswebdav/pid-3175261-dt-content-rid-9111547_1/courses/MEC130.A.180071/MEC130%20Formatted%2013.4.16.pdf a4a

Question 10

What could you employ in the machining process to enable you to use faster cutting speeds?

Answer 10

Use a cutting fluid, such as water or oil, or, ideally, a mixture of the two.

Question 11

• Structural adhesives

Provide a sentence describing the basic function of each process.

Answer 11

Structural Adhesives use an adhesive to bond two metal parts together. The bond requires a good degree of overlap between each.

Question 12

• Welding (Fusion and Solid State)

Provide a sentence describing the basic function of each process.

Answer 12

Welding (Fusion and Solid State) – The faces of two parts are melted/softened and pushed together to form a join. Typically, the faces are pushed together first, then heated to form a chemical bond.

Question 13

• Brazing and soldering

Provide a sentence describing the basic function of each process.

Answer 13

Brazing & Soldering – Two parts are connected by a filler metal is placed at or between the surfaces to be joined. The filler metals used melt above 450°C (below the melting temperature of metals to be joined)

Question 14

• Mechanical Fastening

Provide a sentence describing the basic function of each process.

Answer 14

Mechanical Fastening – achieved by the use of bolts, buts, screws, pins, etc. Strength is imparted to the joint by mechanical interlocking and interference of the surfaces brought about by a clamping force. There is no fusion/adhesion between the surfaces.

Question 15

Investment Casting is a disposable mould casting technique. Give three advantages and two disadvantages of the technique.

Answer 15

Advantages are: “Excellent surface finish”, “High dimensional accuracy”, “Almost unlimited intricacy”, “Most metals can be cast” and “No flash or parting line concerns”
Disadvantages are: “Costly pattern and moulds”, “High labour cost” and “Time consuming”