Cutting-Tool Technology and Related Topics Review Questions

Question 1

What are the 2 principal aspects of cutting-tool technology?

Answer 1

• tool material
• tool geometry

Question 2

Name the 3 modes of tool failure in machining

Answer 2

• FRACTURE FAILURE
• TEMPERATURE FAILURE
• GRADUAL WEAR

Question 3

What are 2 principal locations on a cutting tool where tool wear occurs

Answer 3

• Top Face of cutting tool
  
  • crater wear
  • side/flank wear
• Tool Point
  
  • nose radius wear

Question 4

Identify mechanisms by which cutting tools wear during machining

Answer 4

• abrasion
• adhesion
• diffusiom
• plasticdeformation of the cutting edge

Question 5

What is the physical interpretation of the parameter C in the Taylor’s tool life euqation

Answer 5

C repsresents the cutting speed

Question 6

Identify 3 desirable properties of a cutting tool material

Answer 6

• Toughness to resist fracture
• hot hardness to resist temperature failure
• wear resistance to prolong life of tool

Question 7

What are the principal alloying ingredients in high-speed steel

Answer 7

• Tungsten-type
• Molybdenum-type

Question 8

What is the difference in ingredients between steel cutting grades and nonsteel cutting grades of cemented carbide

Answer 8

Non-cutting grades contain only WC and Co

Steel cutting grades contain TiC and/or TaC in addition to WC-Co

Question 9

Identify some of the common compounds that form the thin coatings on the surface of coated carbide inserts

Answer 9

titanium

carbide

titanium nitride

aluminum oxide

Question 10

Name the seven elements of tool geometry for a single-point cutting tool

Answer 10

back rake angle

side rake angle

end relief angle

side relief angle

side cutting edge angle

nose radius

end cutting angle

Question 11

Name the 2 main categories of cutting fluid according to function

Answer 11

lubricants

coolants

Question 12

Name the 4 categories of cutting fluid according to chemistry

Answer 12

cutting oils

emulsfied oil

chemical fluids

semichemical fluids

Question 13

What are the methods by which cutting fluids are applied in a machining operation

Answer 13

flooding

mist appliction

manual application

Question 14

What are the problems associated with the use of cutting fluids

Answer 14

• Can be contaminated with foreign substances
• odors and health issues
• Does not perform lubrication function due to contaminants
• Disposal of old fluids have become more costly

Question 15

What are some of the probelms introduced by dry machining

Answer 15

• overheating
• operating at lower cutting speeds and production rates in order to prolong tool life
• absence of chip removal benefits in grinding and milling

Question 16

Define machinability

Answer 16

Relative ease with which material can be machined using appropriate tooling and cutting conditions

Question 17

What are the criteria by which machinability is commonly assessed in a production machining operation

Answer 17

• Tool Life
• Cutting force
• power
• surface finish
• ease of chip disposal

Question 18

What are factors on which he selection of feed in a machining operation should be based

Answer 18

• tooling
• roughing or finishing
• constraints on feed in roughing
• surface finishing requirements in finishing

Question 19

The unit cost in a machining operations is the sum of 4 cost terms. What are those terms

Answer 19

• cost of part handling
• cost of machining tim
• cost of tool change time
• tooling cost

Question 20

Which cutting speed is always lower for a given machining operation, cutting speed for minimum cost, or cutting speed for maximum production rate? Why?

Answer 20

CUTTING SPEED FOR MINIMUM COST

Question 21

Identify alternative ways in which cutting tool is held in place during machining

Answer 21

• Solid shank
• brazed inserts
• mechanically clamped inserts