(a) The BCC iron has a density of 7882 kg/m³ and the lattice parameter of 0.287 nm when hydrogen atoms are introduced at interstitial positions. Evaluate (i) the atomic fraction of hydrogen atoms (ii) the number of unit cells on average that contain hydrogen atoms (b) The strength values of a tungsten-tantalum alloy and its related properties are shown in the table below: Grain diameter (mm) Strength (MPa) 0.071 140 0.110 134 0.203 129 0.314 126 Determine (i) the constants in the Hall-Petch equation. (ii) the grain size required to obtain strength of 300 MPa.

(a) The BCC iron has a density of 7882 kg/m³ and the lattice parameter of 0.287 nm when hydrogen atoms are introduced at interstitial positions. Evaluate (i) the atomic fraction of hydrogen atoms (ii) the number of unit cells on average that contain hydrogen atoms (b) The strength values of a tungsten-tantalum alloy and its related properties are shown in the table below: Grain diameter (mm) Strength (MPa) 0.071 140 0.110 134 0.203 129 0.314 126 Determine (i) the constants in the Hall-Petch equation. (ii) the grain size required to obtain strength of 300 MPa.

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

See similar textbooks

Similar questions

(b) Chromium has the iron (monoatomic body-centered cubic) structure. Its density is 7.19 g.cm³, and the length of the edge of the unit cell is 288.4 pm. Use these data to calculate a value for the Avogadro constant. (4)
(c) Three-dimensional hexagonal boron nitride is made up of sheets of the two- dimensional material described above. X-ray diffraction is used to measure the distance between adjacent rows of boron atoms in the layers, and the distance between the two-dimensional sheets. i. Draw diagrams to show how a single-crystal sample of BN must be orientated with respect to the incident and scattered beams in order to make these measurements.
The P=T phase diagram of iron(Fe) is shown below, where the - Fe and -Fe phases are in body-centered cubic(bcc) structure, while the - Fe is in Face-centered cubic(fcc) structure. (a) Draw schematic G-T diagrams of Fe at 1 and 10^-8 atm and the G-P diagram at 1500 C. (b) Please draw schematic H-T and S-T diagrams of Fe at 1 atm. (d) Please draw schematic G-T and G-P diagrams of Fe at the fcc-liquid-Vapor triple point. (e) Please estimate the enthalpy change and entropy change of one mole of Fe being heated from 30 to 1500 °°℃. (f) Please estimate the enthalpy changes of one mole of fe under the → phase transformation at 500 and 1200 °C. (e) Please calculate the heat of evaporation of Fe at the normal boiling temperature. (h) Please explain why the phase boundaries of,, and /liquid equilibria are much steeper than those with the vapor phase in the phase diagram. Note: Please make sure the slopes and curvatures are with physical meanings
If you want to determine the glass transtion tempreture (Tg), softening point (Ts), melting point (Tm) and crystallization temperatures (Tc) of the glass-ceramics which characterization techniques can be used? Plase expain in details.
a) Draw rock salt unit cell of NaCl and give the coordinates (u,v,w) describing the positions of all the atoms in such a unit cell. b) Calculate the structure factor |F_hkl|^ 2 for such a unit cell for x-ray scattering from a given set of crystallographic planes (hkl). c) Which reflection peaks have the lowest and highest intensities and why
(a) The unit cells of three structural types of ionic solids are shown below (the anions appear light and the cations dark). The anions occupy the lattice positions. X (B) (A) (i) Name the common structural type for (A), (B) and (C). (Hint: a typical structural type is rutile (T1O₂).] (C) (ii) The structures (A), (B) and (C) can be considered as packing of anlons with the cations occupying specific types of hole. For each structure: state the unit cell that the packing of anions is based on. state which holes are occupied by the cations and what fraction of them are occupied. State the coordination numbers of the cations and anions for (A), (B) and (C).
QUESTION 2: A part of the phase diagram of X and Y elements that can be mixed isomorphically is given above. 1300 SIVI Alloy at point A; It contains 35% X and 65% Y and is 1250 oC. a) Calculate the percentage of liquid and solid phases of the alloy at a+ SIVI point A. b) Calculate the ratio of X and Y in% of the liquid and solid phases of 1200 the alloy at point A. 20 30 40 50 31 35 42 (3-) wyeis
Complete the table below. Name of Hypothetical Crystal Volume, V, in cm3 Length of one side of the cell, Crystal Radius, r, in Structure cm I, in cm (2) (4) (6) ZORRO FCC 0.9813 (1) LUFFY ВСС (3) (5) 65.3111 SANJI SC 12.7890 (7) (9) (8) (10) NAMI FCC 5.0000 ROBIN ВСС 49.7965
(c) State any assumptions that are made regarding close packing of atoms in crystalline solids compared to covalent bonding. (d) Draw the unit cell for a body-centered cubic (BCC) unit cell. Identify ALL contributions to the overall atom count.
What is the effect of temperature on molar conductivity?
B: Define the coordination number and its value for BCC unit cell.
Two patterns of packing for two different circles of the samesize are shown here. For each structure (a) draw the twodimensionalunit cell; (b) determine the angle between thelattice vectors, g, and determine whether the lattice vectorsare of the same length or of different lengths; and (c) determinethe type of two-dimensional lattice