Mae 272 ch 2-8 Exam Questions and Answers
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Explain why studying the types of chips produced is important in understanding cutting
operations. They significantly influence the surface finish produced, cutting forces, as well
as the overall cutting operation
· Continues chips = good surface finish & steady cutting force
· Discontinues chips = poor surface finish & dimensional accuracy & cutting forces that fluctuate
Tool life can be almost infinite at low cutting speeds. Would you then recommend that all
machining be done at low speeds? Explain. No. While tool life increases at low speeds, it
also reduces production rates. You need high speed machine with suitable tool materials.
Explain the consequences of allowing temperatures to rise to high levels in cutting. · Tool
wear (e.g., flank and crater wear, thermal cracking)
· Built-up edge formation
· Poor surface finish
· Residual stresses in the part
, How does the depth of cut affect cutting force? Greater depth of cut results in more
material removed, leading to higher resistance and increased cutting force.
What effect does a lower rake angle have on cutting force? A lower rake angle makes the
tool geometry less favorable, requiring more force to shear the material.
Why is it not always advisable to increase the cutting speed in order to increase the production
rate? · Higher speeds can cause faster tool wear and thermal damage
· May lead to poor surface finish or built-up edges
· Increases operational cost due to more frequent tool changes
Which tool-material properties are suitable for interrupted cutting operations? Why? ·
High impact strength and toughness
· Utilized material with low coefficient of thermal expansion (constantly reheated)
· High thermal conductivity (Minimize thermal stress)
Describe the reasons for and advantages of coating cutting tools with multiple layers of different
materials. · Coating material may not bond well directly with tool surface
· Increase life of the tool
Verified by Experts
Explain why studying the types of chips produced is important in understanding cutting
operations. They significantly influence the surface finish produced, cutting forces, as well
as the overall cutting operation
· Continues chips = good surface finish & steady cutting force
· Discontinues chips = poor surface finish & dimensional accuracy & cutting forces that fluctuate
Tool life can be almost infinite at low cutting speeds. Would you then recommend that all
machining be done at low speeds? Explain. No. While tool life increases at low speeds, it
also reduces production rates. You need high speed machine with suitable tool materials.
Explain the consequences of allowing temperatures to rise to high levels in cutting. · Tool
wear (e.g., flank and crater wear, thermal cracking)
· Built-up edge formation
· Poor surface finish
· Residual stresses in the part
, How does the depth of cut affect cutting force? Greater depth of cut results in more
material removed, leading to higher resistance and increased cutting force.
What effect does a lower rake angle have on cutting force? A lower rake angle makes the
tool geometry less favorable, requiring more force to shear the material.
Why is it not always advisable to increase the cutting speed in order to increase the production
rate? · Higher speeds can cause faster tool wear and thermal damage
· May lead to poor surface finish or built-up edges
· Increases operational cost due to more frequent tool changes
Which tool-material properties are suitable for interrupted cutting operations? Why? ·
High impact strength and toughness
· Utilized material with low coefficient of thermal expansion (constantly reheated)
· High thermal conductivity (Minimize thermal stress)
Describe the reasons for and advantages of coating cutting tools with multiple layers of different
materials. · Coating material may not bond well directly with tool surface
· Increase life of the tool
