2.1.3. The complete solutions to the general model is rather complex. Some of the simplified
models for which solutions are attempted are listed below:
1. One dimensional steady flow (x or r directions) with constant or variable properties,
without heat g

334
CHAPTER 11
Dispersion Strengthening and Eutectic Phase Diagrams
(Sn) appears in both the a and b phases, the mass of Sn in the b phase will be
11 1:836 g 8.164 g. Note that in this case the b phase at 0 C is nearly
pure Sn.
(e) Lets now calculate the

358
CHAPTER 12
Dispersion Strengthening by Phase Transformations and Heat Treatment
duce the most desirable dispersion strengthening
as discussed in Chapter 11:
9
The matrix should be relatively soft and
ductile and the precipitate, or second
phase, shoul

Problems
319
Phase diagrams Diagrams showing phases present under equilibrium conditions and the phase
compositions at each combination of temperature and overall composition. Sometimes phase
diagrams also indicate metastable phases.
Phase rule See Gibbs

10-5 Isomorphous Phase Diagrams
307
However, when two phases, such as liquid and solid, coexist, their compositions
dier from one another and also dier from the original overall composition. In this
case, if the original composition changes slightly, the

11-5 Strength of Eutectic Alloys
60
Tensile strength (MPa)
50
343
Figure 11-18
The effect of the composition and
strengthening mechanism on the
tensile strength of lead-tin alloys.
40
30
20
10
0
The aluminum-silicon eutectic phase diagram (Figure 11-19) f

7-10 Evaluation of Creep Behavior
217
Figure 7-22
Photomicrograph of a metal near a stresscorrosion fracture, showing the many
intergranular cracks formed as a result of the
corrosion process (200). (From ASM
Handbook, Vol. 7, (1972) ASM International,
Ma

286
CHAPTER 9
Principles and Applications of Solidification
Spherulite Spherical-shaped crystals produced when certain polymers solidify.
Superheat The pouring temperature minus the freezing temperature.
Thermal arrest A plateau on the cooling curve durin

376
CHAPTER 12
Dispersion Strengthening by Phase Transformations and Heat Treatment
Figure 12-15
The effect of interlamellar spacing (l)
on the yield strength of pearlite.
at the grain boundaries of the original austenite grains. We can increase the numbe

412
CHAPTER 13
Heat Treatment of Steels and Cast Irons
EXAMPLE 13-6
Design of a Quenching Process
Design a quenching process to produce a minimum hardness of HRC 40 at the
center of a 3.75 cm diameter 4320 steel bar.
SOLUTION
Several quenching media are l

466
CHAPTER 14
Figure 14-13
Nonferrous Alloys
(Repeated for Problem 14-22) (a) Heat treatment of the alpha-beta titanium alloys.
14-23 Determine the specic strength of the strongest
Al, Mg, Cu, Ti, and Ni alloys. Use the densities
of the pure metals in yo

454
CHAPTER 14
Nonferrous Alloys
EXAMPLE 14-7
Design/Materials Selection for a High-Performance Jet Engine
Turbine Blade
Design a nickel-based superalloy for producing turbine blades for a gas turbine
aircraft engine that will have a particularly long cre

340
CHAPTER 11
Dispersion Strengthening and Eutectic Phase Diagrams
Note that in these calculations, the fractions have been rounded o to the
nearest percent. This can pose problems if we were to calculate masses of different phases, in that you may not b

13-11 Cast Irons
427
calcium oxide (CaO). In nodulizing, Mg is added, usually in a dilute form such as an
MgFeSi alloy. If pure Mg is added, the nodulizing reaction is very violent, since the
boiling point of Mg is much lower than the temperature of the l

11-1 Principles and Examples of Dispersion Strengthening
examine the types of reactions that produce multiple-phase alloys. Finally, we examine, in some
detail, methods to achieve dispersion strengthening by controlling the solidification process. We
will

442
CHAPTER 14
Nonferrous Alloys
Figure 14-3 (a) Sand-cast 443 aluminum alloy containing coarse silicon and inclusions.
(b) Permanent-mold 443 alloy containing fine dendrite cells and fine silicon due to faster
cooling. (c) Die-cast 443 alloy with a still

388
CHAPTER 12
Dispersion Strengthening by Phase Transformations and Heat Treatment
12-15 In the plane own by the Wright brothers, how
was the alloy precipitation strengthened?
12-22 Compare and contrast eutectic and eutectoid
reactions.
Section 12-7 Requ

10-1 Phases and the Phase Diagram
295
Figure 10-2
(a) Schematic unary phase diagram
for magnesium, showing the melting
and boiling temperatures at one
atmosphere pressure. (b) Pressuretemperature phase diagram for
germanium (Ge), ct (4): bodycentered tetr

692
FUNDAMENTALS OF HEAT AND MASS TRANSFER
SHORT PROBLEMS
1. Hot air at 80C flows over a surface of area 0.2 m2 at 60C, the convection coefficient
being 25 W/m2K. The heat flow is _ .
(100 W)
2. The surface temperatures of a slab conducting heat under ste

134
FUNDAMENTALS OF HEAT AND MASS TRANSFER
T 35
cosh 11.89 ( 0159
.
0.08)
=
= 0.4354
200 35
cosh (11.89 0159
.
)
T = 106.84C
(compare at the same location in long fin, 98.74C).
Example 4.3. In the example 4.1, consider the fin to be 80 mm long and end f

161
HEAT TRANSFER WITH EXTENDED SURFACES (FINS)
Problem 4.22: Consider the data in problem P.4.21. If the wall temperature is 300C and if
h = 300 W/m2K and L = 0.08 m determine the error:
Solution:
m=
(hP / kA) = (300 0.01 4 / 55 (0.012 0.008 2 ) = 77.88,

98
FUNDAMENTALS OF HEAT AND MASS TRANSFER
20C
15C
A
B
D E
C
0.25 m
B
C
C
B
0.09
0.1 m
0.09
0.015
0.01
0.015
Fig. 2.37
2.38
A 5 mm dia copper cable is insulated with a material of conductivity of 0.16 W/mK and is exposed
to air at 30C with a convection co

14
FUNDAMENTALS OF HEAT AND MASS TRANSFER
Problem 5: A spherical reactor vessel of outside radius 0.48 m has its outside temperature as
123.4C. The heat flow out of the vessel by convection and radiation is 450 W. Determine the
surrounding temperature.
So

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Published by New Age International (P) Ltd., Publishers
All rights reserved.
No part of this ebook may be reproduced in any form, by photostat, microfilm,
xerography, or any other mean

428
FUNDAMENTALS OF HEAT AND MASS TRANSFER
Problem 9.27: Dry air at a pressure of 8 bar and 20C is chilled in an annulus between a 5 cm
tube and 2.5 cm tube whose walls are kept at 0C by evaporating refrigerant. The length is 6 m.
Determine the exit tempe

377
CONVECTIVE HEAT TRANSFER-PRACTICAL CORRELATIONS-FLOW OVER SURFACES
The applicable equation is
Nu = 2 + 0.386 (Re Pr)0.5 = 13.96
h = 19800 W/m2K
Q = 4 r2h T = 31102 W
This shows that liquid sodium can extract heat at a high rate and so is used in breed

539
HEAT EXCHANGERS
If Ch is considered as Cmin, we get the same result as below, considering equation (12.20).
LM F
IJ OP
G
K PQ
MN H
L UA (1 C )OP = exp [ N(1 C)]
= exp M
N C
Q
Th 2 Tc1
1
1
= exp UA
Th1 Tc2
Ch C c
min
In RHS add and substract Th1 in the