10) Which of the following statements about recrystallisation of metals are true?Select one or more:a. The recrystallisation temperature is equal to the melting temperatureb.It leads to the formation of cold-worked grains with high dislocation densityRecrystallisation leads to an enhanced plastic deformabilityRecrystallisation leads to an increase in yield strengthIt leads to the formation of new grains with no or few dislocationsCold working can change the recrystallisation temperatureO c.d.e.O f.

Answer We know that Recrystallisation temperature is 0.3 - 0.4 times melting point for metals and…

Which of the following statements about recrystallisation of metals are true? Select one or more: O a. The recrystallisation temperature is equal to the melting temperature O b. It leads to the formation of cold-worked grains with high dislocation density O c. Recrystallisation leads to an enhanced plastic deformability O d. Recrystallisation leads to an increase in yield strength e. O f. It leads to the formation of new grains with no or few dislocations Cold working can change the recrystallisation temperature

Which of the following statements about recrystallisation of metals are true? Select one or more: O a. The recrystallisation temperature is equal to the melting temperature O b. It leads to the formation of cold-worked grains with high dislocation density O c. Recrystallisation leads to an enhanced plastic deformability O d. Recrystallisation leads to an increase in yield strength e. O f. It leads to the formation of new grains with no or few dislocations Cold working can change the recrystallisation temperature

Materials Science And Engineering Properties

1st Edition

ISBN:9781111988609

Author:Charles Gilmore

Publisher:Charles Gilmore

Chapter7: Making Strong Materials

Section: Chapter Questions

Problem 1ETSQ

See similar textbooks

Similar questions

In an engineering application, the material is a strip of iron with a fixed crystallographic structure subject to a tensile load during operation. The part failed (yielded) during operation and needs to be replaced with a component with better properties. You are told that two other iron strips had failed at yield stresses of 110 and 120 MPa, with grain sizes of 30 microns and 25 microns respectively. The current strip has a grain size of 20 microns. The diameter of the rod is 1 mm and the load applied is 100 N. What is the yield stress of the new part C and would you recommend it for operation? Select one: Oa. 133.5 MPa, yes O b. OC. Od Oe. 120.5 MPa, no 129.5, yes 140.5, no 123.5 MPa, yes
Q7> Ductile-to-brittle transition temperature (DBTT) is a very important parameter in the design of metallic materials for engineering applications. It has been well known that most of BCC and HCP metals show the DBT phenomenon; however, there is no DBTT in FCC metals. (a) Explain the reason in terms of deformation and fracture. You must compare the BCC and FCC. (b) The ductile fracture surface consists of many dimples. Explain their formation mechanism from the concept of point defects. (c) There are two types in the brittle fracture. Explain and Compare them.
3.What is a dislocation? List five more microscopic defects in bulk materials. Which of the following properties are most sensitive to dislocation structures in materials? a. Young's modulus b. Yield strength c. Conductivity d. Transparency
A cylindrical specimen of cold-worked steel has a Brinell hardness of 240. If the specimen remained cylindrical during deformation and its original radius was 11.8 mm, determine its radius after deformation. For steel, the dependence of tensile strength on percent cold work is shown in Animated Figure 7.19b. i mm
Considering a finite cylinder of single crystal aluminum with a diameter (D) that has an axial unit screw dislocation at the center, what is the stress field around this dislocation in terms of D (diameter of cylinder) and r (radius which is the distance from dislocation center)
Given your understanding of what initiates and controls failure in materials, which of the following will increase the failure strength or lifetime of a test piece or component and why? a. Decreasing the difference between the maximum and minimum stress values, as this effects the stress concentration factor b. Decreasing the temperature below the brittle-ductile transition temperature, to make it harder C. Polishing to reduce surface defects Od. Increasing its volume, to give a larger cross sectional area Oe. Increasing the grain size so there are less grain boundaries to initiate failure
A copper rod is deformed using a uniaxial tensile force of 16000 N. Deformation continues until sufficient strain hardening has occurred such that the applied force is too small to allow further deformation. After deformation, the rod has a diameter of 0.01 m and a length of 1.5 m. Assume that copper follows the strain hardening lawwith K of 310 MPa and n=0.54 Please calculate the true strain after the deformation ?
An iron specimen is plastically deformed in shear by 1%, and it has u dislocation density of 1 10 14 m/ m 3 Assume that the dislocation density did not change in the 1% strain of thisspecimen, the Burger's vector (b) is a 2 [1 1 1] the slip plane is (110). the shear stress isapplied to the (110) plane, and the lattice parameter of the BCC iron is 0.286 nm. Calculate the magnitude of the Burger's vector for these dislocations in iron. Calculate the average distance moved by the mobile dislocations as a result of the 1% shear strain.