ABSTRACT
Pure metals can generally have their properties improved by alloying; this and various forms of heat treatment increases the resistance to deformation, and also affects the conductivity, generally lowering it. Increased strength in alloys occurs because of an increase in the number of dislocations in the lattice structure. Each alloying element lowers σ by a different amount, depending upon its concentration in the host, and how different it is electronically from the host lattice. Conductivity ranges have been established for various alloys. Table 27-1 shows data for aluminum alloys, widely investigated because of their usefulness in the aerospace industry. Conductivity is modified by heat treatment. Aluminum alloy conductivity ranges
Alloy/Temper
Conductivity range (% IACS)
Minimum
Maximum
1100
57.0
62.0
2014-0
48.5
51.5
2014-T3XX/T4XX
31.5
35.0
20I4-T6XX
37.0
41.5
2024-0
45.5
50.0
2024-T3XX
28.0
33.0
2024-T4XX
28.5
32.5
2024-T6XX
35.0
41.0
2024-T8XX
36.0
42.5
2219-0
43.0
46.0
2219-T3XX
27.0
31,0
2219-T6XX/T8XX
31.0
35.5
3003-0
44,5
50.0
6061-0
47.0
51.0
6061-T4XX
35.5
41.5
6061-T6XX
40.0
45.0
7075-0
44.0
48.0
7075-T6XX
30.0
35.0
7075-T73X
38.0
42.5
7075-T76X
36.0
39.0
7079-0
44.0
47.0
7079-T6XX
30.0
35.0
7178-0
43.0
47.0
7178-T6XX
29.0
34.0
7178-T76
35.0
39.0
