INDUSTRIAL AND ENGINEERING CHEMISTRY
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with the worst deviations in the results based on aniline point and low-temperature viscosities. The relationships proposed above are merely approximations and direct determination of a property is preferable to its estimation from other properties. However, it is believed that these charts are of sufficient accuracy to be useful in engineering problems where complete data are not available.
Acknowledgment AcknowIedgment is due J. L. Wien, J. E. Westenberg, and J. 0. Iverson for assistance in experimental work and correlations presented in this paper.
Literature Cited (1) Borgstrom, P.,Norton, R. D., and Lewis, 0. I., J . A m . SOC. Naval Engrs., 46, 173 (1934).
VOL. 17, NO. 12
(2) Davis, Lapeyrous, and Dean, Oil Gus J . , 30, No. 46,92 (1932). (3) FitzSimons, 0.. and Bahlke, W. H., Proc. Am. Petroleum Inat., 11, No. 1, 70 (Jan. 2, 1930). (4) FitzSimons, O., and Thiele, E. W., IND. EKG.CHEM., Anal. Ed., 7, 11 (1935). ( 5 ) Fortsch, A. P., and Wilson, R. E., IND.ENQ.CHEM.,17, 291 (1925). (6) Hill, J. B.,and Coates, H. B., Ihid., 20,641 (1928). (7) Sachanen and Tilicheyev, "Chemistry and Technology of Cracking," New York, Chemical Catalog Co., 1932. (8) Sweeney, W. J., and Voorhees, A., IND.EKG.CHEM.,26, 197 (1934). (9) Watson, K.M., Oil Gus J., 33,No. 11, 34 (1934). (10) Watson, K. M., and Nelson, E. F., IND.ENG.CHEM.,25,880-7 (1933). ENG.CHEM.,Anal. Ed., 7, (11) Watson, K. M.,and Kirth, C., IND. 72 (1936). RECEIVED M a y 6, 1935. Presented before the Division of Petroleum Chemistry a t the 89th Meeting of the American Chemical Society, New York, N. Y., April 22 t o 26, 1935.
A New Low-Melting Alloy SIDNEY J. FRENCH, Colgate University, Hamilton, N. Y
HE fusible quaternary eutectic alloy usually called "Lipowitz eutectic alloy" is commonly given the following percentage composition: bismuth, 50; lead, 27; tin, 13; and cadmium, 10. The alloy melts sharply a t 72' C. and freezes at 70" C. No other alloy composed of these four metals melts below 72' C. although some references give the melting point of Wood's metal (bismuth, 50; lead, 25; tin, 12.5; and cadmium, 12.5) as low as 60' C. The addition of indium gives quinternary alloys having melting ranges below those of the quaternary alloys.
QT
Preparation of Quinternary Alloys Quinternary alloys containing indium were prepared by adding successive amounts of indium to the quaternary eutectic alloy. The quaternary alloy was prepared from c. P. metals which were accurately weighed, placed in a hard glass test tube, and heated t o 325" C. The molten alloy was stirred constantly while cooling. The melting and freezing points of the quaternary eutectic alloy were determined by means of cooling and melting curves. Fifteen grams of the alloy were then placed in a small soft glass test tube and melted. Indium was added and the alloy was heated to 160" C. The alloy was then permitted to cool in an air bath and was constantly stirred during the process to prevent undercooling. The approximate freezing range was thus determined. Table I sho-xs the freezing ranges of these alloys. Since no changes were made in percentages of the other metals present, the ratios of bismuth t o tin to cadmium remained as they were in the quaternary eutectic alloy, The percentages given in Table I are approximate since the alloys were not analyzed. ~
TABLE I. FREEZINQ POINTS OF ALLOYS Lipowita Indium Alloy
%
%
100.00 99.01 95.04 97.55 95.48 94.02
0.00 0.99
93.11 91.24
89.46 57.76
1.96
2.95 4.54 5.98 8.89 8.76 10.54 12.26
Freezing Range
c.
Lipowitz -4110~
Indium
Freezing Range
c.
%
%
69.7 68.0M9.5 65.5 -68.00 63.00-65.5 61.5 -63.5
86.09 84.50
13.91 15.50 16.85
56.00-59.5 54.00-57.00 5 2 . 5 -55.5 50.6 -53.00
77.66
21.18 22.34
4 8 . 5 -51.00 48.00-50.00 47.00-48.5 47.00-48.5 47.00-48.5 47.5 -49.00
50.00
33.34 60.00
58.00-59.00
a
67.00-60.5
83.15 51.64 80.19 78.82
75.00 88.67
18.36
19.81 25.00
0
49.5 -52.00
48.00-50.00 49.00-51.00
Each successive alloy was obtained by adding a n accurately weighed amount of indium t o the previous alloy. Table I indicates that there is a regular fall in the freezing range as the percentage of indium is increased; the minimum is obtained when the percentage of indium reaches 18 to 20 per cent.
Cooling and Melting Studies Cooling and melting curve studies were made of alloys containing the following percentages of indium: 28.30, 25, 22.34, 19.25, 18.58, 18.10, 17.79, and 16.50: The alloy containing 28.30 per cent indium was first prepared by adding the required amount of indium to 12 grams of Lipowits alloy which had been prepared as indicated above. The other alloys were prepared in turn by the addition of appropriate amounts of Lipowitz alloy. It was thus unnecessary to remove any of the alloys from the tube in which the determinations were made. A small soft glass test tube was used for the studies. The thermometer, which was compared with a Bureau of Standards certified thermometer, TYas placed with the bulb in the molten alloy and was used to stir the alloy, The test tube was placed in an 800-cc. water bath surrounded, in turn, by an air bath. The water was stirred with a motor stirrer. The bath was cooled by direct contact with the air of the laboratory, the rate of cooling being about 0.3" C. per minute. In determining melting curves, the bath was heated with a small shielded gas flame so that the rate of temperature rise was about 0.3' C. per minute. Figures 1 and 2 show cooling and melting curves for alloys containing 16.5, 18.10, and 22.34 per cent indium. The percentages of indium given in the figures were not determined by analysis of the alloy but indicate merely the amount of indium added to the quaternary alloy. The alloy containing 18.1 per cent indium froze sharply at 46.7' C. and melted sharply a t 46.9" C. The other alloys showed greater meltingfreezing ranges; none had a final solidifying temperature below that contJaining 18.1 per cent indium. Figure 3 compares the cooling curves of two quinternary alloys in which the percentages of bismuth, lead, tin, and cadmium were varied and the percentage of indium was kept constant a t 18.1 per cent. The composition of one of these alloys was the same as that shown in Figures 1 and 2; in the other the ratio of bismuth to lead t o tin was 4 t o 2 to 1. The percentage compositions were as follows:
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IADUST11SAL A N D ENGIPrEEHlNG CHEMISTRY
DECEMUEII, tY35 :In 1ii:Pb:Sa S1.S:lR.l 4:2:1
I . i p a r i t , u Alloy
I?! Pb I O
Srr Cd
40.95
42.06
22.11 18.10 l0.lJd 8 20
22.03 18.10 10.60 8.20
The nUuy containing 81.9 per cent Lipowitz nirtal and 18.1 percent iniliumfrozeiharplyat 46.,j" C, a i d nhowed a distinct flat,tening of the cooling curve; the o t h e r a l l o y b e g a n t o solidify nt 47' C. and was complptelr solid at 4F.4"C., shoiring a retardation of the cooling ciirve hegiriiiirrg a t 47' C.
Applications Wecaott! of the high price of imliimnr, the low-melting quiuternary dloy would cost close to five do1la.rs an ounce in small 1ot.s. In large lots the cost might lie cut in half. Fut.ure price reductions in indiuni may bring the cost of the alloy down to a parity with silver. The alloy cannot hope to compete with I,ipoivit,z alloy or Wood'.; metal hut may find use where cost is a minor item or where the alloy lnay Re recovered without loss. The human body C ~ I Icome in direct cont,aat with the nrdten nlhy without disconrfort. This fact suggests us
