12. What are is an impact tests. Sketch the impact testing machine setup and explain the basic principle of toughness determination from it. What is DBTT? sketch the impact energy vs temperature curve for plain carbon steel and discuss why do many materials become brittle at low temperatures.

What is the difference in appearance between ductile & brittle fractures?

3000 kg, 10mm Steel Ball Brinell Hardness Reading of 421 is equal to what Rockwell C Reading?

Need answer correctly

5) Draw the stress-strain curve and gives the stress and strain equations for both Engineering and True stress-strain What is the impact test, why it used and what the main difference between its methods?

sketch

A material with a low dislocation density will have a higher yield stress as compared to a material having a high dislocation density True False

QUESTION 1 Select from the following statements, those which describe the process and conditions required for brittle fracture. (Note: Partial credit is not available for this question. Credit will only be awarded if all correct answers, and no incorrect answers, are selected). A. Occurs along defined crystallographic planes, thus leaving smooth fracture surfaces B. Occurs due to repeated loading and unloading below the yield strength of the material OC. Occurs in materials where the bonding strength is high relative to the yield strength D. The stress concentration at the crack tip exceeds the inter-atomic bonding energy ☐ E. Involves the nucleation, growth and coalescence of voids, thus resulting in rough fracture surfaces OF. Is a slow process whereby there is warning prior to failure

Which curve shown below (A or B) is for a BCC metal and why? A В Brittle + More Ductile Temperature Duclile-o-britte transilion temperalure Impact Energy

Draw a typical stress vs strain tensile test curve for the following material and label the axis. A typical brittle material subjected to a tensile stress that has been applied to the material till the sample breaks. 1- label the axis and draw the curve for a brittle material. 2- indicate the maximum strength of the material. 3- show on the portion of the curve where young's modulus can be calculated.