Reach On The Effect Of Orthogonal Rolling And Heat Treatment On The Microstructure And Mechanical Properties Of Al-5Cu Alloy

As a common 2-series aluminum alloy,aluminum-copper alloy has a wide range of application prospects in aerospace and automobile manufacturing due to its high strength,good ductility,and low density.In this paper,orthogonal rolling deformation was used to improve the properties of cast Al5 Cu alloy,which greatly improved the strength and elongation of the alloy.At the same time,the optimal aging state was obtained by studying the changes in the mechanical properties of the orthogonally rolled Al5 Cu alloy under different aging temperatures and different aging times,so that the strength and elongation of the alloy were improved.Subsequently,the alloy sample in the optimal aging state was cold-rolled deformation,so that the strength of the Al5 Cu alloy was significantly improved.In this paper,the mechanical properties and microscopic morphology of the Al5 Cu alloy under different conditions are studied through tensile test,scanning electron microscope(SEM),transmission electron microscope(TEM),etc.,and the mechanisms that affect the mechanical properties of the alloy were obtained,which provide a theoretical basis for the preparation of high-strength aluminum alloys.The research content of this article is now introduced as follows:(1)The microstructure of the cast Al5 Cu alloy was coarse and there was a large amount of eutectic structure in the matrix,and its yield strength and elongation were only 55.9MPa and 4.1%.After rolling and orthogonal rolling of the as-cast alloy,the microstructure of the alloy was refined,and the distribution of the eutectic structure in the matrix was more uniform,so that the yield strength of the alloy was increased to171.9MPa and 176.7MPa,and the elongation reached 6.8% and 10.2%.At the same time,the homogenization treatment was carried out at 520? for 24 h before the orthogonal rolling,so that the ultimate tensile strength and yield strength of the alloy reached 213.2MPa and 177.9MPa,and the elongation increased to 16%.Therefore,orthogonal rolling after homogenization treatment can make the performance improvement of the as-cast Al5 Cu alloy more significant.(2)It was subjected for the orthogonally rolled Al5 Cu alloy samples after homogenization to solution treatment at 520? for 10 h,and then the aging treatment was started.In the process of aging heat treatment,the Al5 Cu alloy samples after solution treatment were respectively subjected to aging treatment at 160? for 1h,3h,5h and 7h.So that,it found that the performance of Al5 Cu alloy is greatest when the aging time is 5h.Subsequently,in order to clarify the effect of aging temperature on alloy properties,the solution sample was subjected to aging treatment at 140?,180?and 200? for up to 5h.It was concluded that the mechanical properties of the Al5 Cu alloy reached the best under the aging state of 160?,5h,and its ultimate tensile strength and the yield strength reached 398.7MPa and 254.1MPa,and the elongation reached 12.7%.Observation of the microstructure in this state by a transmission electron microscope(TEM),it can be obtained that the average size of the precipitated phase was 16.69 nm,and it presents a sandwich structure in the microscopic state,such as ??/GP zone/??.At the same time,there was an interlamellar nesting structure between the grains in the microstructure of the alloy.(3)Cold rolling deformation can effectively improve the mechanical properties of Al5 Cu alloy.By performing 40%,50%,and 80% rolling deformation of samples after aging treatment at 160? for 5h,the ultimate tensile strength and yield strength of the Al5 Cu alloy have been significantly improved,the ultimate tensile strength reached486.7MPa,497 MPa and 561.8MPa,and the yield strength reached 453.9MPa,466.1MPa and 530.3MPa,but the elongation dropped sharply after deformation.Subsequently,the Al5 Cu alloy samples with a deformation of 80% were subjected to aging treatment at 120?,for 30 min and 150 min,which increased the elongation from1.8% to 8.7%,and the tensile strength decreased to 529.2MPa.Finaliy,the tensile strength,yield strength and elongation of the Al5 Cu alloy at 120?,150 min aging state increased by 311.8%,741.5% and 93% respectively compared with the as-cast Al5 Cu alloy.It is concluded that the homogenized Al5 Cu alloy after the orthogonal rolling deformation treatment can effectively refine the microstructure and improve the mechanical properties of the alloy,and in the subsequent aging treatment at 160°C,for5 h,there were a large number of fine and dispersed nano-scale precipitates in the Al5 Cu alloy matrix,which present the sandwich structure.Combined with the interlemallar nested structure between the grains,the mechanical properties of the alloy were improved again.Finally,the mechanical properties of the Al5 Cu alloy were further improved by cold rolling and aging heat treatment,which optimized the microstructure and mechanical properties of Al5 Cu alloy.