Author Question: What is the likely effect on modulus of adding a filler? Why? What will be an ideal ... (Read 99 times)

tiara099 · **on:** Aug 19, 2018

What is the likely effect on modulus of adding a filler? Why?

What will be an ideal response?

Question 2

What is the purpose of notching Izod or Charpy samples?

What will be an ideal response?

dajones82 · **Reply #1 on:** Aug 19, 2018

Answer to Question 1

Modulus will likely increase by adding most common fillers. The reasons are that the filler is itself a stiff material. Secondly, the filler will likely fill into the spaces between the molecules and thus inhibit the molecules from moving over each other. This resistance to intermolecular motion is seen as an increase in modulus.

Answer to Question 2

One of the important aspects of impact toughness is the tendency of the material to fail through cracking. Cracks often begin at sharp locations as is created when a notch is installed in the part. Therefore, a key reason to notch the sample is to determine the tendency to fail by cracking. Another, perhaps equally important reason, is to provide a point at which failure is likely to occur so that the failure values from one test to another will be less dependent on the initiation of the failure and more dependent on the crack propagation through the material.