Full text of DOI:10.1361/105994900770345809

JMEPEG (2000) 9:408-415
᭧ASM International
The Jominy End Quench for Light-Weight Alloy
Development
J.W. Newkirk and D.S. MacKenzie
(Submitted 2 December 1999; in revised form 22 March 2000)
The Jominy end quench test is well known as a method of measuring hardenability in steels. In nonferrous
alloys, there is a desire to determine the effect of quenching on final properties after heat treating. The
Jominy end quench test offers a method for studying many quenching conditions with a minimum of
samples. The potential for developing a new understanding of the complex response of nonferrous alloys
to processing conditions, especially quenching, will be presented. Examples of the properties measured on
Jominy end quench specimens of aluminum and titanium alloys will be presented.
changes, this geometry was never adopted as a standard test
method.
Keywords aging, aluminum alloys, heat treatment, Jominy,
quenching
Hergat[5] described precautions that should be taken to
achieve a 1 HRC precision when conducting the test. These
improvements include making sure that the machined flats on
the specimen are parallel and that the operator error induced
during hardness testing is reduced by the use of semiautomatic
hardness machines. It is also necessary to ensure that the speci-
men is in a fixture that ensures accurate positioning and firmly
holds the specimen. It was found that the Vickers hardness test
provided much better repeatability. Brown[6] also found that
Vickers hardness measurements provided much better repeat-
ability and allowed for more data to be taken because the
indentations could be spaced much closer together, improving
the signal-to-noise ratio. It was found that the precision of the
test was also improved by the use of a calibrated positioning
device that held the specimen firmly in place. One of the advan-
tages cited for the use of Vickers hardness is that the measure-
ments can be readily rechecked by measuring the diagonals
again or by placing an additional indention alongside the dis-
puted reading. He found that the repeatability of the standard
Rockwell-type test was typically 2 HRC. Using a 15 kg load,
he found that the variability of the hardness measured by Vickers
was roughly half that of the Rockwell test. In his concluding
comments, he indicated that accurately determined hardenabil-
ity curves often show that the test introduces the scatter rather
than does the steel.
The nature of the hardness distribution at specific distances
in the Jominy end quench test was investigated by Sheikh.[7]
Three different steels were examined, with the intent of under-
standing the scatter that occurs when testing. Probability plots
were created from the hardness data on the three steels and
interpreted. It was determined that the hardness scatter at each
location on the Jominy end quench is normally distributed and
therefore would be bounded by a 3-sigma around the mean.
The expected probability distribution can be used to predict
and establish upper and lower control limits for heat treatment.
Kura and Lorig[8,9] measured cooling rates as a function of
austenitizing temperature, quenchant temperature, composition,
and plate thickness. They described higher quench rates at the
quenched end of the test bar than that of Jominy. This is probably
due to the age of the instrumentation. Several cooling curves
1. Literature Review
In this section, a brief review of the available literature on
the use of the Jominy end quench test will be described. The
previous use of the Jominy end quench test for nonferrous
alloys will be discussed, and the specific use of the Jominy
end quench test for aluminum alloys will be shown.
2. Jominy End Quench
In the original classic work by Jominy and Boegehold,[1]
they described a cylindrical specimen 100 mm long by 25 mm
in diameter. The specimen was austenitized and then removed
from the furnace and placed in a fixture, where the specimen
was exposed at one end to a specified vertical stream of water.
The resulting cooling is one dimensional and is invariant on
the composition of the steel. But the resulting hardenability
of the steel, as measured by hardness, is dependent on the
composition and grain size of the steel. The simple design of
the specimen, and the relative ease of the test procedure, has
made this test the preferred method to measure the hardenability
of steel. The popularity and repeatability of the test has resulted
in the test procedure being adopted in ASTM,[2] SAE,[3] and
other agencies’ test methods. A schematic of the method is
shown in Fig. 1.
Jominy[4] also described a test specimen with a slightly
different configuration that was designed for shallow hardening
steels. It provided for much faster cooling rates. This specimen
was called the “type L specimen” and had a conical section
removed from the quenched end to a depth of approximately
25 mm. The quenching conditions were changed slightly, requir-
ing a free unimpeded water rise of 100 mm. Because of difficult-
ies in machining and the sensitivity to small dimensional
J.W. Newkirk and D.S. MacKenzie, University of Missouri - Rolla.
Rolla, MO 65409.
408—Volume 9(4) August 2000
Journal of Materials Engineering and Performance

Royce Aerospace, Postans[11] investigated the use of the Jominy
end quench test for titanium alloys. He was able to use this
technique successfully to establish the best alloy and quench
rate for specific applications. He showed schematically how
the microstructure of various titanium alloys varied as a function
of cooling rate.
4. Jominy End Quench—Aluminum Alloys
There has been limited published work on the use of the
Jominy end quench test for aluminum alloys. Loring et al.[12]
authored the first published paper on the use of the Jominy end
quench test for studying aluminum alloys using a modified L-
type Jominy specimen. The cooling curves at various distances
up to 25 mm were measured. Different types of aluminum
(14S, 24S, 61S, R-301, and 75S) were tested. Hardnesses were
measured at 3 mm intervals using the Rockwell B, F, and
Vickers (5 kg) scales. Further, it was seen that higher quench
rates yielded decreasing hardness in the as-quenched condition.
Low cooling rates produced relatively small changes in the
hardness. Only 75ST exhibited a sensitivity to quench rate
after aging.
In the work by ‘tHart et al.,[13] the Jominy end quench test
was applied to extruded rods of 2024 and 7075. The bars were
aged to the 2024-T4, 2024-T6, and 7075-T73 conditions. The
Jominy bars were evaluated by transmission electron micros-
copy (TEM) and corrosion testing to examine the relationship
between quench rate, corrosion properties, and microstructure.
The cooling rate of Jominy specimens fabricated from 2024
and 7075 were measured. Vickers hardnesses were taken at 5
mm intervals. It was found that 7075 was strongly quench
sensitive and that hardness increases were only found in the
first 60 mm of the bar. It was found that the quench rate and
tempering operation influenced the widths of the precipitate
free zone (PFZ). With only two data points, it was shown that
faster cooling rates made for thinner PFZ.
The authors also evaluated 7010 and P/M 7091 aluminum
alloys heat treated to the T6 and T73 tempers.[14] Corrosion
properties and microstructure were determined as a function of
cooling rate. It was found that 7010 was quite quench-insensi-
tive compared to 7075. It was found that the alloys were insensi-
tive to SCC and EXCO. No effect related to quench rate was
found. It was also observed that the PFZs in 7091 and 7075
were more dependent on quench rate than that of 7010.
Using an apparatus similar to a Jominy end quench,
Hecker[15] evaluated aging cycles as a function of time for an
Al-Mg-Si alloy. It was shown that silicon has a marked effect
on the age hardening of Al-Zn-Mg-Cu aluminum alloys.
Alternative methods of end quenching, similar in principal
to the Jominy end quench, have been tried. Bomas[16] deter-
mined the time-temperature-property diagram of an Al-Zn-Mg
alloy. This was accomplished using a rectangular specimen 15
ϫ 140 ϫ 300 mm, with the 15 ϫ 140 mm face of the specimen
exposed to the quenchant stream. This enables the specimen
to be exposed to one-dimensional heat transfer, in the same
fashion as the Jominy end quench test. Tensile specimens were
laid out perpendicular to the axis of the quench medium and
enabled to be taken as a function of cooling rate during quench.
Arthur et al.,[17] used an apparatus similar to Bomas to develop
Fig. 1 Schematic of the Jominy end quench
are provided. Plates from 12.5 to 100 mm thick were examined.
The severity of quench using Grossman quench factors was
estimated for water and oil and correlated to plate thickness
for the Jominy end quench test conditions. It was determined
that the hardness within the cross section of a plate closely
approximates that measured by the Jominy end quench test at
equivalent cooling rates. This is applicable regardless of the
quenchant or thickness of the plate, since it is a function of
cooling rate.
3. Jominy End Quench of Nonferrous Alloys
There has been some published work on the use of the
Jominy end quench test for nonferrous alloys. Toda[10] measured
the critical cooling rates for Cu-Cr, Cu-Be, and Cu-Co2Si using
the Jominy end quench method. The cooling rates of these tests
were determined using a pen-recording oscilloscope. It was
determined that the critical cooling rate for the alloys investi-
gated was the cooling rate that caused a decrease in properties.
It was defined as the cooling rate necessary to obtain a supersat-
urated solid solution at room temperature. Both as-quenched
and aged hardnesses were taken. In a study sponsored by Rolls
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Volume 9(4) August 2000—409

Table 1 Elemental chemistry of purchased 7075 and 7050 extruded rounds
Elemental chemistry (wt.%)
Specimen
Cu
Fe
Si
Mn
Mg
Zn
Ni
Cr
Ti
Zr
7075-T6
7050-T7451
1.36
2.11
0.20
0.12
0.10
0.050
0.04
0.04
2.62
1.98
5.77
5.74
0.003
Ͻ0.000
0.20
0.026
0.0170
0.031
0.0115
0.09
models on the development of residual stresses during quench-
ing in several aluminum alloys. He developed several constitu-
tive equations used for modeling the heat transfer and
mechanical properties at elevated temperatures. To determine
the thermal conductivity, since it was unavailable for the temper-
atures of interest, an estimate of the thermal conductivity was
made by fitting the thermal conductivity equation to the cooling
curves. This is not a rigorous method but was adequate for
their purposes.
Using an end quench apparatus similar to Arthur, Becker et
al.,[18] presented very detailed constitutive models for Al-5.6%
Mg alloy and pure aluminum. Models, as a function of tempera-
ture, included density, heat capacity thermal conductivity, ther-
mal expansion, and mechanical properties. These models also
provided the basic activation energies and other information
for the temperature compensated strain rate (Z).
5. Experimental Procedure
The use of the Jominy end quench on a titanium alloy
(Ti-6V-4Al) and two aluminum alloys (7075 and 7050) was
accomplished. This was accomplished by validating the basic
technique and examining whether radial heat transfer occurred.
Once the basic technique had been validated, then hardness
measurements and microstructure examination of the Ti-6V-
4Al and aluminum alloys could be performed.
Fig. 2 Jominy end quench fixture used
the smaller size of the jominy end quench specimens eliminated
the narrow recrystallization layer at the surface of the aluminum
extrusions. Any evidence of alpha-case on the titanium was
also machined away. After machining, the specimens were
cleaned in acetone to remove any trace of cutting fluids or
hand oils.
The aluminum jominy end quench specimens were placed
inside the furnace and heat treated for 1 h at 471 ЊC. The
titanium specimens were heat treated for 1 h at 900 ЊC. While
the test specimens were reaching the desired temperature, the
setup of the Jominy end quench fixture was verified. The height
fixture used is shown in Fig. 2.
Once the specimens had soaked at temperature, the furnace
door was opened and the specimens were grabbed one at a time
using either tongs or insulated gloved hands. The specimens
were placed on the Jominy fixture and the water flow to the
nozzle was initiated. The time elapsed between the time the
door was opened and the time the water flow was initiated was
approximately 5 s. The temperature drop of the furnace during
specimen removal was about 4 ЊC. The specimen was allowed
to cool for approximately 5 min. Once the temperature of the
specimen was below 60 ЊC, then the specimen was removed
from the fixture. The aluminum specimens were immediately
placed in a chilled methanol bath at a temperature of Ϫ50 ЊC.
This was done to control the time prior to aging. The titanium
6. Raw Material
A length of 7075-T6 (37 mm diameter) and a length of
7050-T7451 (75 mm diameter) extruded rods were purchased
for initial testing. The elemental chemistry of each of the
extruded rods was verified using induction coupled argon
plasma spectroscopy and compared to traceable standards. The
results of the elemental chemistry are shown in Table 1. The
material was examined for hardness and conductivity to verify
the heat treated condition supplied. It was found that the hard-
ness and conductivity of the 7075 and 7050 extruded rounds
were typical of published values.
A 72 mm diameter rod of Ti-6V-4Al was obtained and
examined for microstructure. The microstructure was found to
be consistent with annealed Ti-6V-4Al. Vendor certificates of
conformance were used for elemental chemistry.
7. Conducting the Jominy End Quench Test
From each of the materials, jominy end quench specimens
were prepared per ASTM A255. The size of the extrusions and
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Journal of Materials Engineering and Performance

specimens were allowed to cool to room temperature. No subse-
quent aging was performed on the titanium specimens.
After allowing the aluminum specimens to reach the equilib-
rium temperature of the methanol bath, the aluminum specimens
were removed and placed in a room temperature water bath.
After warming to room temperature, the samples were dried,
and the specimens were allowed to sit at room temperature for
120 h. Once this time had elapsed, the specimens were placed
again in the chilled methanol bath to end the natural aging
cycle. This was done to ensure that no additional natural aging
occurred prior to placing the specimens in the aging oven.
After reaching the equilibrium temperature of the bath, each
aluminum specimen was removed from the methanol bath and
placed in room temperature water. Once room temperature had
been reached, the specimens were placed into the recirculating
air aging furnace. Using a programmable temperature controller,
the age cycle for each specimen was established and started.
The aging cycle consisted of a first stage age at 108 ЊC for 5
h, followed by a 5 ЊC per min ramp to 175 ЊC for 8 h.
Fig. 3 Radial hardness traverse of an aluminum Jominy end quench
specimen showing only axial heat transfer
8. Evaluation of Hardness Measuring Technique
Once the specimens had completed all thermal cycles (alumi-
num and titanium), two flats approximately 1 mm deep were
machined from the specimens. After the Jominy end quench
specimen is quenched, the hardness must be measured. The
hardness scale generally used for steel is the Rockwell௣ “C”
scale (Diamond Braile Indenter, 150 kg load). In steel, hard-
nesses are taken every 1/16 in., measured from the quenched
end. For this investigation, the Diamond pyramid hardness or
Vickers hardness scale (1.5 kg load) was used. This hardness
measuring technique allows the indentations to be spaced at
much closer intervals (1/64 in.), enabling the observation of
subtle trends in hardness, and shows improved repeatability.
To ensure accurate positioning, a specially designed fixture
was used. Because the hardness indentations are more closely
spaced, the absolute position and relative interval must be
known accurately. The existing Rockwell Equitron௣ fixture
was modified to allow positioning at much closer intervals
(1/64 in.). A demonstration of the accuracy of the modified
positioning device was accomplished by taking multiple Vickers
hardness readings along a previously hardened Jominy end
quench specimen. The absolute and relative positions of the
hardness indentations were measured using a Nikon Toolmakers
measuring microscope, with a calibrated tolerance of 0.001 in.
While a slight periodic error was apparent, the average relative
indentation spacing is 0.0156 in., with a standard deviation of
0.001 in. This is within the tolerance of the measuring micro-
scope. Accurate positioning was therefore achieved.
Fig. 4 Measure time-temperature curve of an aluminum Jominy end
quench specimen
the sides of the cylinder did not occur. Results are shown in
Fig. 3. The resulting radial hardness traverses are flat, confirm-
ing that heat transfer is along the cylinder axis, with little heat
transfer occurring along the sides.
10. Verification of Cooling Rates
The test specimens were prepared previously by drilling
small (1.5 mm) radial holes at 3.2, 38.1, and 76.2 mm from
the quenched end of the aluminum Jominy specimens. These
holes were drilled to a depth of 12 mm (the center of the
specimen). Type K thermocouple wires (Special Limits of Error,
24 AWG) were inserted into the radial holes until intimate
contact was made. Once the thermocouples or the thermocou-
ples and the wire were inserted, the thermocouples were held
in place using the high temperature fiberglass tape. All thermo-
couples were taken from the same roll and were previously
calibrated.
9. Radial Heat Transfer and Effect on Hardness
A 7050 Jominy end quench test specimen previously heat
treated was sliced at several distances from the quenched end.
These slices were polished using the technique described above.
Radial hardness traverses were taken at several distances from
the quenched end to verify that excessive heat transfer along
The test specimens, with thermocouples attached, were
inserted one at a time, into the middle of the furnace work
Journal of Materials Engineering and Performance
Volume 9(4) August 2000—411

zone, near the furnace control thermocouple. The temperature
readings of the thermocouples were monitored and allowed to
reach the furnace temperature (approximately 25 min). The
parts were allowed to soak for 45 min. The data acquisition
unit was activated and allowed to collect steady-state tempera-
ture data. The data acquisition rate was 50 Hz.
The resulting time-temperature cooling curves are presented
in Fig. 4. The cooling rate at specific temperatures was deter-
mined by taking the time and temperature 25 ЊC above and
below the desired temperature on the time-temperature cooling
curves. These curves show that there is a progressive change
in the cooling rate as the distance from the quenched end
is increased.
11. Jominy End Quench Evaluation of Ti-6V-4Al,
7075, and 7050 Aluminum
In this section, several examples of the use of the Jominy
end quench test in examining two nonferrous systems will
be illustrated.
11.1 Titanium
A 72 mm round of Ti-6V-4Al was machined to conform to
the Jominy end quench specimen dimensions. The specimen
was solution heat treated in the aˆ region and quenched in the
Jominy fixture. Two flats were machined from the Jominy
Fig. 5 Ti-6V-4Al Jominy end quench hardness profile
Fig. 6 Microstructure changes in Ti-6V-4Al as a function of quench rate and position on the JEQ bar: (a) J ϭ 2 mm, (b) J ϭ 10 mm, (c) J ϭ
50 mm, and (d) J ϭ 100 mm
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Journal of Materials Engineering and Performance

specimen, and a hardness traverse was performed (Fig. 5). The
results show that the hardenability of this alloy is low, with the
region of highest hardness very shallow.
Photomicrographs taken along the length of the titanium
Jominy end quench specimen show a dramatic change in
microstructures (Fig. 6). In the first several millimeters, the
microstructure is predominately ␣ with prior ␣ grain bound-
aries. As the cooling rate slows, the microstructure becomes
very complex, with evidence of primary ␣, Widmansta¨tten
structure, and ␣ at the prior ␣ grain boundaries. Some acicular
␣ is also present. Upon further cooling, the microstructure
becomes entirely Widmansta¨tten structure. Cooling never
became slow enough to show a completely equiaxed ␣ ϩ
␣ microstructure.
11.2 Aluminum
The resulting hardness and conductivity of the 7050 and
7075 Jominy end quench specimens are shown in Fig. 7.
This shows that 7075 is much more quench sensitive than
7050. In addition, the inflection points on the hardness
curves are nearly identical. The cause of similarity is not
yet known.
Fig. 7 Hardness profiles of 7075 and 7050 aluminum Jominy end
quench specimens
Fig. 8 Microstructure changes in 7050 aluminum as a function of quench rate and position on the JEQ bar: (a) J ϭ 2 mm, (b) J ϭ 10 mm, (c)
J ϭ 50 mm, and (d) J ϭ 100 mm
Journal of Materials Engineering and Performance
Volume 9(4) August 2000—413

Fig. 9 TEM examination of changes in microstructure occurring in 7050 aluminum as a function of quench rate and position on the Jominy end
quench bar: (a) J ϭ 7 mm, (b) J ϭ 31 mm, (c) J ϭ 56 mm, and (d) J ϭ 79 mm
evident. In the final location (J ϭ 100 mm), precipitation is
much more uniform. Parallel and perpendicular grain bound-
aries are more darkly etched. The microstructure is typical of
12. Optical Examination of Aluminum Jominy
End Quench Specimens
an overaged microstructure. These results indicate that initial
The microstructure was also examined optically to evaluate
precipitation occurs in some grains preferentially over others.
whether changes in microstructure could be distinguished as a
This may be related to a preferred orientation of the precipitates.
function of cooling rate. The results of the microstructural
examination of the 7050 and 7075 microstructure are shown
in Fig. 8. At 10 mm from the quenched end, grain boundaries
are outlined parallel to the rolling direction. Very little etching
of the grain boundaries perpendicular to the rolling direction
13. TEM Examination of 7050 Jominy End
Quench Specimens
was observed. Some larger secondary precipitates are visible.
As the cooling rate slows (J ϭ 25 mm), darker grain boundaries
are evident. Etching and precipitation appear to be occurring
preferentially in some grains. Some grain boundaries perpendic-
ular to the rolling direction are evident. At J ϭ 50 mm, increased
precipitation in the interior of the grains and at the grain bound-
aries is observed. Precipitation is still preferred in some grains
more than others. More perpendicular grain boundaries are
Transmission electron microscopy 3 mm disks were prepared
perpendicular to the rolling direction, by taking slices at specific
distances from the quenched end. Specimens were punched
from thin slices and mechanically ground and polished to
approximately 125 ␮m thick. The 3 mm disks were then electro-
polished using 25% HNO3 in methanol at Ϫ20 ЊC. Voltage used
414—Volume 9(4) August 2000
Journal of Materials Engineering and Performance

faster quenching studies to be performed for commercial
heat treating.
The microstructural evolution in the aluminum alloys could
be easily followed by optical microscopy and TEM. Matrix
precipitation and grain boundary precipitation could be fol-
lowed as a function of cooling rate. Measurements of PFZ
widths followed a linear relationship with the Jominy distance.
The results show that the Jominy end quench test is a power-
ful tool to examine the effects of quench rate and heat treating
parameters. The test is appropriate for many different nonfer-
rous alloys, where the alloy has properties that depend on the
quench rate. It is highly recommended for quenching studies
in age hardened aluminum.
Acknowledgments
Fig. 10 PFZ width as a function of distance from the quenched precip-
itation could be followed as a function of cooling rate. Measurements
of PFZ widths followed a linear relationship with the Jominy distance
The authors thank Century Aluminumy, Ravenswood Facil-
ity, for funding this work.
References
1. W.E. Jominy and A.L. Boegehold: ASM Trans., 1939, vol. 27 (12),
p. 574.
2. “Jominy Test, Standard Method for End-Quench Test for Hardenability
of Steel,” ASTM A255, Annual Book of ASTM Standards, ASTM,
Philadelphia, PA.
was 14 V DC. The disks were then examined in a Philips
EM430 at 300 kV.
Using bright-field conditions, images of four positions at
varying distances from the quenched end were taken (Fig. 9).
At a position close to the quenched end (J ϭ 7 mm), the grains
have a strong diffraction contrast. A mottled appearance is
evident from the presence of strain contrast around the coherent
or semicoherent precipitates. No large precipitates were found
except at the grain boundaries. Evidence of serrated grain
boundaries was found, probably from pinning. At slower cool-
ing rates, larger and coarser precipitates from quenching
occurred at the grain boundaries and at the interior of the grain.
The lack of strain contrast indicates that the precipitates are
now incoherent.
The complete width of the PFZ around the grain boundary
and interior quenching precipitates was measured and plotted
as a function of position from the quenched end (Fig. 10). The
results show that the PFZ increases in size as a linear function
of distance from the quenched end. The results demonstrate
clearly the relationship of the PFZ to cooling rate. In addition,
based on the results of the Jominy end quench, the width of
the PFZ can now be predicted. This has great significance
toward the prediction of properties as a function of heat
treatment.
3. “Methods of Determining Hardenability of Steels,” SAE J406c, Annual
SAE Handbook, SAE, Warrendale, PA.
4. W.E. Jominy: ASM Trans., 1939, vol. 27 (12), p. 1072.
5. V. Hergat: Traitement Thremique, 1981, vol. 153, p. 49.
6. G.T. Brown: in Hardenability Concepts with Applications to Steel,
D.V. Doane and J.S. Kirkaldy, eds., AIME, Warrendale, PA, 1978,
p. 273.
7. A.K. Sheikh: Proc. 3rd Int. Symp. on Advanced Materials, 1993, TMS,
p. 696.
8. J.G. Kura and C.H. Lorig: “Correlation of Cooling Velocity of the
Standard Jominy Hardenability Test with the Cooling Velocity within
the Cross-Section of Plates,” Battelle Memorial Institute Report
S-547, Battelle, Columbus, OH, June 2, 1942.
9. J.G. Kura and C.H. Lorig: “Correlation of Cooling Velocity of the
Standard Jominy Hardenability Test with the Cooling Velocity within
the Cross-Section of Plates,” Battelle Memorial Institute Report
S-547, Columbus, OH, July 23, 1942.
10. T. Toda: J. Jpn. Inst. Met., 1965, vol. 29, p. 237.
11. P.J. Postans: “The Use of Jominy End Quench to Assess the Harden-
ability of Higher Strength Titanium Alloys,” DCAF 070028 Rolls
Royce, Oct. 1, London, U.K., 1983.
12. B.M. Loring, W.H. Baer, and G.M. Carlton: Trans. Am. Inst. Min.,
Met. Eng., 1948, vol. 175, p. 401.
13. W.G.J. ‘tHart, H.J. Kolkman, and L. Schra: “The Jominy End-Quench
Test for the Investigation of Corrosion Properties and Microstructure
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14. Conclusions
14. W.G.J. ‘tHart, H.J. Kolkman, and L. Schra: “Effect of Cooling Rate on
Corrosion Properties and Microstructure of High Strength Aluminum
Alloys,” NLR TR 82105 U, National Aerospace Laboratory, NLR,
Netherlands, 1982.
15. D. Hecker: HTM, 1975, vol. 30, p. 268.
16. H. Bomas: HTM, 1975, vol. 30, p. 274.
17. W.E. Arthur, R. Becker, and M.E. Karabin: Proc. Int. Heat Treating
Conf.—Equipment Processing, Rosemont, IL, May 18–20, 1994.
18. R. Becker, M.E. Karabin, and J.C. Liu: Comput. Mater. Modeling -
ASME, 1994, vol. 294, p. 287.
The Jominy end quench has been shown to produce repro-
ducible and expected structures and properties in Ti-6Al-4V,
AAl 7050, and Al 7075. There is no significant effect of radial
heat transfer during the test, making it truly uniaxial heat flow.
Vickers pryamidal hardness yields the best results, in terms of
reproducibility, accuracy, and the ability to resolve differences
over small distances. The cooling rates can be measured and
correlated with cooling rates in various cross sections, allowing
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Volume 9(4) August 2000—415