Tungsten Reinforced Aluminum Composites

Aluminum matrix composites have the advantages of low density, high tensile strength, high modulus of elasticity and high wear resistance. Therefore, aluminium matrix composites have great application potential in aviation and aeronautics.

At present, squeeze casting, pressureless infiltration and spray forming are the main methods to produce aluminum matrix composites. These methods have some shortcomings, such as uneven dispersion of reinforced particles in matrix, poor wettability between reinforced particles and aluminum matrix, high porosity and low economic benefits of the composites.

The reinforcing phases of these aluminium matrix composites are ceramic particles, so their conductivity is limited to a great extent. Electrostatic accumulation seriously threatens the safety of aviation components. Therefore, the electrical conductivity must be taken into account when choosing materials for aeronautical components. It is possible to solve the problem of low conductivity of Al matrix composites reinforced by tungsten particles with higher hardness without sacrificing the excellent mechanical properties of the original Al matrix composites, thus meeting the requirements of Aeronautical component materials. Therefore, researchers believe that the cumulative overlay rolling welding method can be used to fabricate tungsten reinforced aluminium composites.

The surface of annealed 1060 industrial pure aluminium sheet with size of 150 mm x 100 mm x 7 mm was polished with steel wire brush, and then cleaned with alcohol. 29g pure tungsten particles with diameter of 10-15 um were evenly laid between two sheets of aluminium. The two sheets were stacked and placed in a muffle furnace at 350 ℃. After heating for 10 minutes, they were rolled on a rolling mill with diameter of 300 mm and length of 220 mm. The rolling speed and reduction are 0.4m/s and 50% respectively without lubricating oil. After rolling, air cooling is carried out to room temperature. The composite plate after the first rolling is cut off from the middle. The surface of the plate is polished and cleaned with steel brush and alcohol respectively. The pure tungsten particles (29g) with the same quality as the first rolling are evenly laid between the two plates after the first rolling. The second rolling is carried out after heating at 350 ℃ for 10 minutes. The rolling conditions are the same as those for the first time. Repeated shearing, grinding and cleaning, laying pure tungsten particles, stacking, heating and rolling to the fourth pass. Finally, TUNGSTEN-ALUMINIUM composite sheet was synthesized. The composite sheets were sheared, polished, cleaned, stacked, heated and rolled 11 times. Finally, tungsten reinforced aluminium composite sheets with uniform particle distribution were obtained.

The mechanical properties of tungsten reinforced aluminium composites have been greatly improved without destroying the excellent conductivity of pure aluminium. Its yield strength is 130-152 MPa, tensile strength is 145-160 MPa and Brinell hardness is 50-63HB, which are 3.25-3.8 times, 1.812-2 times and 1.72-2.172 times of annealed 1060 industrial pure aluminium respectively.

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