The effect of adding Ca on the microstructural and mechanical properties of as-cast Mg-11Li-3Zn-1Sn(wt%) alloys were investigated. Mg-11Li-3Zn-1Sn-0.4Mn with different Ca additions (0.4, 0.8, 1.2 wt%) were cast under an SF6 and Co2 atmosphere at 720 oC. The cast billets were homogenized at 400 oC for 12h and extruded at 200 oC. The microstructural and mechanical properties were analyzed by OM, XRD, SEM, and tensile tests. The addition of Ca to the Mg-11Li-3Zn-1Sn-0.4Mn alloy resulted in the formation of Ca2Mg6Zn3, MgSnCa intermetallic compound. By increasing Ca addition, the volume fraction and size of Ca2Mg6Zn3 with needle shape were increased. This Ca2Mg6Zn3 intermetallic compound was elongated to the extrusion direction and refined to fine particles due to severe deformation during hot extrusion. The elongation of the 0.8 wt% Ca containing alloy improved remarkably without reduction strength due to the formation of fine grain and Ca2Mg6Zn3 intermetallic compounds by Ca addition. It is probable that fine and homogeneous Ca2Mg6Zn3 intermetallic compounds played a significant role in the increase of mechanical properties.
Hot rolling of Mg-6Zn-0.6Zr-0.4Ag-0.2Ca-(0, 8 wt%)Li powder was conducted at the temperature of 300 oC by putting the powder into the Cu pipe. The microstructure and mechanical properties of the samples were observed. Mg-6Zn- 0.6Zr-0.4Ag-0.2Ca without Li element was consisted of α phase and precipitates. The microstructure of the 8 wt%Li containing alloy consisted of two phases (α-Mg phase and β-Li phase). In addition, Mg2Zn3Li was formed in 8%Li added Mg-6Zn-0.6Zr- 0.4Ag-0.2Ca alloy. By addition of the Li element, the non-basal planes were expanded to the rolling direction, which was different from the based Mg alloy without Li. The tensile strength was gradually decreased from 357.1 MPa to 264 MPa with increasing Li addition from 0% to 8%Li. However, the elongation of the alloys was remarkably increased from 10 % to 21% by addition of the Li element to 8%. It is clearly considered that the non-basal texture and β phase contribute to the increase of elongation and formability.
퍼플루오르옥탄설포네이트를 LC/MS/MS를 이용하여 분석한 결과 분석 대상물질의 고유한 스팩트럼을 얻어 정량 하여 머므름 시간은 4.33분이었으며 상관계수(R2)은 0.9998 로 양호한 직선상의 그래프를 얻을 수 있었다. 퍼플루오르옥탄설포네이트에 대한 분석법의 회수율은 99.84%로 전반적으로 좋은 회수율을 보였으며 또한 이 연구에 적용되기에 충분한 정밀도와 정확도를 가지고 있음을 확인할 수 있었다. 퍼플루오르옥탄설포네이트 정량한계 및 검출한계 는 0.03, 0.009 ug/L이었다. 따라서 식품 용기포장재에서의 분석에 적용이 가능하였다.