A Comprehensive Treatise on Inorganic and Theoretical Chemistry

PL.ATINUM 227
and H. Gonnington, the hydrogen-oxygen reaction. W. A. Nemiloff discussed the
microstructure of the alloys. W. A. Nemiloff's observations on the Brinell's
2400
2300°
2200°
2100
2000
mod
I /
/
/
/
1800°
\l770°
1700
0 20 40 BO 8O Wf)
Per cent of Iridium
KiG. 73. The Liquidus
Curvn of !Platinurnlridium
Alloys.
/
?34 20
/
Ff
C
/ 7/
r
10 \/—\
^ ^ 2 »
300
250
200' j
"J
150 *
1001 i
c
50
20 40 60
100
KiG. 74.
Per cent of Indium
The Tensile Strength and Hardness
Platinurn-Iridium Alloys.
of
hardness are summarized in Fig. 74, and the same diagram gives the tensile strength
of the alloys in kgrms. per sq. mm.—vide Table IV.
J. Weerts obtained the dimensions a of the parameters
of the face-centred cubic lattice of the alloys shown in
Fig. 75. F. Goldberger and O. Kienberger studied the
streak as an indication of the composition of the alloy.
W. Geibel observed that alloys made into wires 1 mm.
diameter, had a breaking load, in kilograms, of
«, 4 00, 1
Iridium
Load
O
24
5
40
IO
48
15
66
2O
81
25
98
' 3-90
Ar_
« 3-8O1 20 40 60 80
Atom, per cent. Pt
100
FIG. 75. The I-attice Parameter
of the Ir-Pt Alloys.
3O
114
35 per cent
126 kgrms.
K. Steinmann's results for the effect of annealing on the tensile strength are summarized
in Fig. 76. K. B. Thews gave 40 kgrms. per sq. mm. for a 5 per cent,
iridium alloy, and 100 kgrms. per sq.
mm. for a 25 per cent, iridium alloy.
E. M. Wise and J. T. Eash gave for
the alloy with 20 per cent, iridium,
reduced 50 per cent, by cold drawing,
the ultimate strength 140,500
lbs. per sq. in., proportional limit
101,000 lbs. per sq. in., elongation
2-5 per cent, in 2 in., a reduction
in area of 85 per cent. ; after a
softening anneal at 1400°, the ultimate
strength was 93,500 lbs. per sq.
in. ; proportional limit, 59,5CX) lbs.
per sq. in. ; elongation, 20 per cent,
in 2 ins., and reduction of area, 88
per cent. F. E. Carter gave for
Brineirs hardness, H, Ericson's ductility
test in mm.; and the resistance, R ohms per million feet
Iridium
H$ Hard
^Annealed .
fHard
DuctilityjAnnealed|l
-R . .
.
.
.
.
uoo°
1200°
O
97
47
7-8
12-2
12-2
6O
5
170
110
71
10-7
10-7
12O
0° 200° 400" 600° 800° 1000T 1200 1400
Fio. 76. The Effect of the Annealing Temperature
on the Tensile Strength.
IO
22O
150
71
100
10-4
16O
15
280
190
70
9-7
10-2
185
2O
33O
230
70
9O
9-7
2OO
25
37O
270
4-1
80
7-8
2lO
3O per cent
4OO
31O
—
20
210