CMS Manufacturing Processes & Techniques 3

Question 1

In injection molding, 'sink marks' on a plastic part are most commonly caused by:

Accepted Answer

Insufficient cooling time leading to localized shrinkage at thick sections

Answer

Sink marks form when thick sections cool and shrink inward before the outer skin solidifies, creating visible depressions on the part surface.

Question 2

Which honing process characteristic distinguishes it from grinding?

Accepted Answer

Honing uses abrasive stones with reciprocating and rotating motion at low speed to improve bore geometry

Answer

Honing uses bonded abrasive stones that simultaneously rotate and reciprocate at relatively low speeds, primarily improving bore geometry, surface finish, and size accuracy.

Question 3

The Taylor tool life equation (VT^n = C) describes the relationship between cutting speed and tool life. What does a higher value of the exponent 'n' indicate?

Accepted Answer

The tool material is less sensitive to cutting speed — tool life changes less with speed variation

Answer

A higher 'n' value (closer to 1) means tool life is less sensitive to changes in cutting speed, indicating a more thermally stable tool-workpiece combination.

Question 4

In sheet metal bending, 'springback' refers to:

Accepted Answer

The elastic recovery of the bent sheet that reduces the final bend angle after the load is removed

Answer

Springback is the elastic recovery that occurs when the bending force is released, causing the part to partially return toward its original shape and reducing the achieved bend angle.

Question 5

Which non-destructive testing (NDT) method is most effective for detecting subsurface cracks in non-ferromagnetic conductive materials like aluminum?

Accepted Answer

Eddy current testing

Answer

Eddy current testing uses electromagnetic induction to detect subsurface discontinuities in conductive materials, including non-ferrous metals like aluminum.

(CMS) Certified Manufacturing Specialist Practice Test

(CMS) Certified Manufacturing Specialist Practice Test

CMS Manufacturing Processes & Techniques 3