The 6151 aluminum alloy plate alloy was born in the United States in the mid-1930s. It was listed as a very rare alloy by the Aluminum Association of America on December 12, 1963. There are currently 5 alloys of this type commonly used: 6151, 6351, 6351A, 6451 6951 alloy. Except 6351A is a French alloy, all others are American alloys. This type of alloy has a wide range of applications in military ordnance, for the manufacture of crankcase forgings and rolling rings, mines and machine forgings. All parts that require good forging performance, relatively high strength and good corrosion resistance can be processed with this alloy. In 1954 he was named alloy 6151.
chemical composition
The gauge length of the lower mechanical properties of 6151 aluminum alloy plateis 50mm or 4d (d is the diameter of the sample). Type 6151 alloy has no low-temperature brittleness and can be used to process parts working at extremely low temperatures. The tensile strength Rm = 330N / mm2 at 25 ℃, the yield strength Rp0.2 = 298N / mm2, and the elongation A = 17%. When the temperature is lowered to 200 ° C, all properties will rise comprehensively, reaching 395N / mm2, 345N / mm2, 20%, respectively. The working temperature of 6151 alloy should not exceed 120 ℃.
Physical properties
The density of 6151 aluminum alloy plate at 20 ° C is 2700kg / m3; the liquidus temperature is 649 ° C, the solidus temperature is 588 ° C, and -50 ° C-the average linear expansion coefficient of 20 ° C is 21.8μm / (m · k), 20 ° C— —The average linear expansion coefficient at 100 ℃ is 23.0μm / (m · k), 20 ℃ —The average linear expansion coefficient at 200 ℃ is 24.1μm / (m · k), and the average linear expansion coefficient at 20 ℃ —300 ℃ is 25.0μm. / (M · k).
Equal volume conductivity of 6151 type alloy at 20 ° C: 54% IACS in O-state material, 42% IACS in T4 state, 45% IACS in T6 state; Resistivity at 20 ° C: 32nΩ · m, T4 in O-state material 41nΩ · m in the state, 38nΩ · m in the T6 state; specific heat capacity at 20 ° C 895J / (kg · K); thermal conductivity at 20 ° C: 205W / (m · k) in O-state material, 163W / in T4 state (M · k); 175W / (m · k) in T6 state.
Process characteristics
The annealing specification of 6151 aluminum alloy plate type alloy is 413 ℃ / (2h——3h). It is cooled to 260 ℃ with the furnace at a cooling rate of not more than 27 ℃ / h, and then air-cooled. Solution temperature (510 ° C-525 ° C) / 4min, quenched in room temperature water, large forgings are quenched in 65 ° C-100 ° C water. Specification of artificial aging (165 ° C-175 ° C) / (8h-12h). The hot processing temperature is 260 ℃ ——480 ℃.
