Chen Yegao, Shi Yunyang, Zhang Anmin, et al. Microstructure of One Step Forming 7075 Aluminum Alloy by Spray Deposition and Continuous Extrusion. [J]. Special Casting & Nonferrous Alloys 41(12):1518-1524(2021)
DOI:
Chen Yegao, Shi Yunyang, Zhang Anmin, et al. Microstructure of One Step Forming 7075 Aluminum Alloy by Spray Deposition and Continuous Extrusion. [J]. Special Casting & Nonferrous Alloys 41(12):1518-1524(2021) DOI: 10.15980/j.tzzz.2021.12.014.
Microstructure of One Step Forming 7075 Aluminum Alloy by Spray Deposition and Continuous Extrusion
7075 aluminum alloy was prepared by spray deposition and continuous extrusion to eliminate the defects such as element segregation
coarse structure and uneven distribution of second phase and shrintage porosities and holes
and the microstructure and element distribution were compared with those of the as-cast alloy. The results indicate that the spray deposited and continuous extruded 7075 aluminum alloy has low content of impurity elements
fine microstructure and uniform distribution of alloying elements. The OM microstructure reveals that the average grain size of the deposited blank is significantly reduced compared with that of the casting alloy
presenting equiaxed crystal. After continuous extrusion
the matrix density is increased
and the second phase is refined and distributed uniformly along the extrusion direction. The TEM microstructure observes that the billets undergo dynamic recrystallization during continuous extrusion
and the average recrystallized grain size is 3~5 μm. The yield strength and elongation of alloy after retrogression and re-aging treatment reach 493 MPa and 12.6%
which exceed 9.6% and 26% of the aviation standard AMS 4050 H limit
respectively. The EDS results demonstrate that the segregation of the main alloy elements prepared is well inhibited
and the impurity elements of oxygen and carbon are more evenly distributed
which is conducive to improving comprehensive properties of the alloy.
关键词
高合金化喷射沉积连续挤压7075铝合金微观组织
Keywords
High AlloyingSpray Deposition and Continuous Extrusion7075 Aluminum AlloyMicrostructure