Papers by Keyword: Zn Content

Abstract: Weld defects - such as porosity and hot cracking - occur especially during the laser beam welding of high-alloyed Al-Zn alloys. This significantly limits the application range of these promising high-strength alloys. In the present study the laser weldability of different Al-Zn alloys was investigated regarding the used welding parameters and the chemical composition of the alloys. In addition, the novel approach of the Helmholtz-Zentrum Geesthacht for overcoming the weldability problems was applied to the different Al-Zn alloys in order to assess its capability. It was shown that the laser weldability of Al-Zn alloys deteriorates with an increasing amount of Zn, Mg and Cu. The variation of laser beam welding parameters did not lead to any improvement of weldability. Only the use of the new approach resulted in promising welding results even for the high-alloyed Al-Zn alloys.

Abstract: After selecting 23 samples from street pavement dust in Suzhou city, this article analyzed the Zn content in street dust with X-RF fluorescence spectrometer analysis and carried on the ecological risk evaluation. The results show that the Zn content in Suzhou street dusts is from 121 to 538 (mg / kg), and distribution characterized of different functional areas as follows: the business district > the vicinity of the station>the rest area of culture and education > the residential area> the industrial area; the accumulation index values is between 0.76 and 1.78, which is non-polluting or moderately polluted.

Abstract: Developing new alloys and techniques is important for the applications of magnesium alloy products. The greatest challenge in the area is to exploit new wrought magnesium alloys[1]. In this paper, the effects of Zn addition on the microstructures and mechanical properties of the MZK60 wrought alloy which is modified from ZK60 have been investigated. The microstructures of these alloys at various states were evaluated by optical microscopy. The mechanical properties at room temperature of these alloys were studied systematically by tensile test. Experimental results indicated that increasing Zn content to 7~10%wt is able to get not only higher tensile strength and yield strength, but also higher elongation.

Abstract: The influence of Zn content and Zn/Mg ratio on the equilibrium phase amounts of major ageing strengthening phase η’ (MgZn2) in lithium containing 7000 series aluminum alloys has been investigated by means of thermodynamic calculations. The results show that, comparing with Li-free 7000 series aluminum alloys, Zn/Mg ratio is no longer the determinant for the amount of η’ and only increasing Zn content that can increase the amount of η’. And the results were discussed with existing experiments.