Font Size: a A A

Heat Treatment Process The Impact Of The New 6xxx Series Aluminum Alloy Microstructure And Properties

Posted on:2011-05-24Degree:MasterType:Thesis
Country:ChinaCandidate:G P ZhangFull Text:PDF
GTID:2191360305494295Subject:Materials science
Abstract/Summary:PDF Full Text Request
Three kinds of Al-Mg-Si alloy with trace elements adding were studied. The microstructures, fracture and mechanical properties of the alloy were analyzed with optical microscope, X-ray diffraction, scanning electron microscopy and electronic testing machine. A sort of Al-Mg-Si-Cu serie alloy with equal strength and higher elongation comparing with the conventional 6082 alloy was optimized. On T6, the 3# alloy has a maximal tensile strength(σb)beyond 310MPa, and elongation ratio (8) beyond 15%. The affect of solution temperature, solution time, delay aging time and artificial aging for mechanical properties of the alloy were studied by Orthogonal experimental method; The corrosion mechanism and corrosion rate on different states were studied by electrolytic corrosion and salt spray corrosion. The conclusions are summarized as follows:1. Al-0.4Mg-0.45Si-1.0Cu aluminum alloy has a wide range of solution temperature and the proper solution temperature is between 520~580℃. The proper solution process is solution treated between 520℃~580℃for 40 min. SEM observation shows that after solution treated at 520℃for 40 min. residual particles in the matrix are bigger a-Al15(FeMn)3Si2 and P-Al9FeSi, and smaller Mg2Si.2. The best natural aging time of the alloy is 72 hours. On T4 the tensile strength and elongation of the 3 alloy are 277Mpa and 28.6%(stable value).3. The best artificial aging process parameter:165℃/10h. The corresponding mechanical properties:ab equal 331MPa,σ0.2 equal 243Mpa,δequal 17.1%. Not only did it have reached the required target but also had perfect feasibility.4. Stay time on the quenched alloy is not sensitive. Its mechanical properties change a little in 5 hours of the delay aging time, which adapted the industry process parameter very well.5. It has good corrosion resistance. The artificial aged alloy after 72h salt spray corrosion has a corrosion depth about 622μm, some second phase particles were abscission.
Keywords/Search Tags:Al-Mg-Si-Cu alloy, heat treatment, microstructure, mechanical property, corrosion resistance
PDF Full Text Request
Related items