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Mg-6Zn-1Y (mass fraction, %) alloys were prepared for degradable biomaterials. The billets of the alloy were produced by powder metallurgy (PM) method and then hot extruded. The extruded samples were aged for 24 and 72 h at 150 °C. The microstructure and corrosion behavior of the experimental alloys were investigated. The microstructure observations indicate that the alloys contain α-Mg, MgZn, MgZn2 and Mg3YZn6 (I-phase) phases. The hot extrusion process significantly refines the grains and leads to better mechanical properties with the value of compressive strength in the range of 365∼399 MPa, and better corrosion resistance for the PM alloy shows higher hydrogen volume in the immersion test. Furthermore, due to more uniform corrosion behavior, the alloy aged for 72 h presents lower corrosion rate and corrosion current density in the immersion test and potentiodynamic polarization test, and higher resistance value (Rp) results from the electrochemical impedance spectroscopy (EIS), which means the alloy aged for 72 h exhibits better corrosion resistance than the other three alloys.

The effects of ultrasonic treatment on the microstructure and properties of twin roll casting Mg-2.45%Al-0.92%Zn-0.69%Ce-0.21%Mn alloy strip were studied. The results show that the ultrasonic treatment improves strength, elongation and limiting drawing ratio of the alloy strip. The highest limiting drawing ratio of the sheet is 2.16 at 250 °C. The improvement of properties is attributed to the refinement of α -Mg grains and the modification of Mg 17 (Al, Zn) 12 and AlCeMn phases by ultrasonic treatment during the twin roll casting process. The grain size of the twin roll casting strip is refined from 150 μm to less than 30 μm with the ultrasonic treatment power of 800 W, and the needle-like shape of the AlCeMn phase is modified to a globular shape; therefore, the mechanical properties and formability of the magnesium alloy sheet are improved.

The cold roll bonding process of an Al-Ni layer composite sheet applied as a brazing solder for the welding of nickel and aluminum structures in the lithium-ion battery packaging was investigated. The effects of roll bonding and annealing treatment on the application properties and the interface compounds of Al-Ni composite sheet were also studied. The results show that the appropriate rolling reduction to bond and produce Al-Ni layer composite sheet is between 50% and 60% deformation degree. During the annealing process, the first formed Al 3 Ni phase in the interface of Al and Ni is beneficial to the bonding of such two metals, but the sequently formed Al 3 Ni 2 phase results in cracks and separation of the Al-Ni layers. The roll-bonded Al-Ni layer composite sheet acquires good bending endurance, stable weldability and suitable electrical resistivity upon annealing at 698 K to 748 K for 1 h.

Al-50wt.%SiC composites containing three types of SiC particle sizes(average23µm, 38µm and 75µm) were fabricated by powder liquid-phase sintering. The influences of SiC particle sizes and anneal on the properties were investigated in the study. The results show that the composites with coarse SiC particles can obtain higher thermal conductivity (TC), higher coefficient of thermal expansion(CTE) and higher relative density, while the composites with finer SiC particles are able to have lower CTE and enhance the flexural strength of the composites effectively. Besides, after the annealing at 500 °C for 6 hours, the shape and size of SiC particles in the annealed composites are not changed nearly, compared with those in the sintered composites. In addition, the CTE and flexural strength of the annealed composites are decreased, and the TC is improved a little. From the results obtained, it is credible that Al-50wt.%SiC composites can possess good potential for electronic packaging application.