(In) Indium Alloys
AIM is a leading global supplier of indium and indium alloys. Indium is a unique, low-melting ductile metal that will weld under relatively low pressure. Indium wets metallic and non-metallic surfaces. Indium alloys have a wide range of melting points, the lowest being the indium/tin alloy 118 C° eutectic. These alloys are a good choice to solder gold surfaces, where the gold has to remain intact. Indium alloys show excellent fatigue resistance when thermal mismatches are encountered. Indium alloys perform very well when operating temperatures do not exceed 120 C°.
|
Alloy Composition |
Melting Range (°C) |
Tensile Strength (ksi) |
Density |
CTE (x10-8 / °C) |
Creep Resistance |
|
80Au/20Sn |
280 |
276 |
14.5 |
16 |
Excellent |
|
88Au/12Ge |
356 |
185 |
14.7 |
13 |
Excellent |
|
96.5Sn/3.5Ag |
221 |
38 |
7.36 |
21 |
High |
|
95Sn/3.5Ag/1.5In |
218 |
51 |
7.36 |
22 |
High |
|
91Sn/9Zn |
199 |
65 |
7.27 |
n/a |
Good |
|
63Sn/Pb37 |
183 |
32 |
8.40 |
25 |
Moderate |
|
62Sn/Pb36/Ag2 |
179 |
46 |
8.41 |
27 |
High |
|
CASTIN |
217 |
40 |
7.30 |
40 |
High |
|
SAC305 |
218 |
40 |
7.40 |
40 |
High |
|
40In/60Pb |
195-225 |
34.5 |
9.31 |
26 |
Moderate |
|
70In/30Pb |
160-174 |
23.8 |
8.19 |
28 |
Moderate |
|
80In/Pb15/Ag5 |
148-149 |
17.5 |
7.85 |
26 |
Moderate |
|
100In |
156.7 |
2.5 |
7.31 |
29 |
Poor |
|
97In/3Ag |
146 |
5.5 |
7.38 |
22 |
Poor |
|
52In/48Sn |
118 |
11.9 |
7.30 |
24 |
Low |
|
58Bi/42Sn |
138 |
55 |
8.56 |
14 |
Moderate |
|
40Bi/60Sn |
138-170 |
n/a |
8.12 |
14 |
Moderate |
|
54Sn/26Pb/20In |
138-150 |
n/a |
8.10 |
25 |
Moderate |
|
35.7Sn/35.7Pb/28.6Bi |
100 |
24 |
9.34 |
20 |
Low |
(Cd) Cadmium Alloys
This group of alloys is typically used for EMF shielding when cadmium content is in the 70% range. Tin, lead, and cadmium are an excellent choice if low temperature soldering is required. The alloy of 18Cd/32Pb/50Sn wets very well and has a high joint strength. Tin, lead, cadmium or silver are often used when a mechanical joint is needed on aluminum or other difficult to solder materials.
|
Cadmium Alloys |
Ag |
Cd |
Pb |
Sn |
Melting Point C° |
Density |
|
Cd 70 |
70 |
30 |
140-160 |
.2770 |
||
|
Cd 18 |
18 |
32 |
50 |
145 |
.3051 |
|
|
Cd 1 |
3.5 |
1 |
32 |
65 |
216-219 |
.2657 |
(Bi) Bismuth Alloys
Bismuth is added to an alloy to reduce melting temperatures. These alloys do not wet as well and have lower peel strength than tin/lead alloys. They are the least expensive of the low temperature alloys, and bismuth is considered to be a less toxic metal. Bismuth/tin alloys are considered safe for potable water systems. They are also used for mechanical bonds as well as lead-free alternatives for the jewelry industry.
|
Bismuth Alloys |
Bi |
Pb |
Sn |
Melting Point C° |
Density |
|
Bi 58 |
58 |
42 |
138 |
.3090 |
|
|
Bi 52 |
52 |
32 |
16 |
100 |
.3465 |
|
Bi 46 |
46 |
20 |
34 |
100-105 |
.3500 |
|
Bi 14 |
14 |
43 |
43 |
144-163 |
.3245 |
|
Bi 8 |
8 (+.2) |
46 |
46 |
120-167 |
.3166 |
(Au) Gold Alloys
Gold Alloys are the best choice when soldering to gold-based materials. They are considered to be high reliability alloys, with excellent thermal and electrical properties. Gold alloys are excellent for corrosion resistance when hermetic seals need to be formed.
|
Gold Alloys |
Au |
Ge |
In |
Si |
Sn |
Melting Point C° |
Density |
|
Au 99 |
98(±.2) |
2.0 |
370-800 |
.6133 |
|||
|
Au 97 |
96.8(±.2) |
3.2 |
370 |
.5564 |
|||
|
Au 88 |
87.5(±.2) |
12 |
356 |
.5301 |
|||
|
Au 82 |
81.5(±.2) |
18 |
451-485 |
.5383 |
|||
|
Au 80 |
79.5(±.2) |
20 |
280 |
.5242 |
(Ga) Gallium Alloys
The combination of Gallium/Indium results in a low temperature alloy that can be liquid at room temperature. These alloys can be used to replace Hg in applications such as motion switches and thermostats. Gallium/Indium alloys are also used for thermal management applications.
|
Gallium Alloys |
Ga |
In |
Sn |
Melting Point C° |
Density |
|
Ga 75 |
75.5 |
24.5 |
15.7 |
.2294 |
|
|
Ga 62 |
62.5 |
21.5 |
16 |
10.7 |
.2348 |
 |
|
