H.Z. Huang
,
X.Q. Wei
,
L. Zhou
,
null
,
null
金属学报(英文版)
The potential of using a hypoeutectic, instead of eutectic, Sn-Zn alloy as a lead-free solder has been discussed. The nonequilibrium melting behaviors of a series of Sn-Zn alloys were examined by differential thermal analysis. It was found that at a heating rate of 5℃ / min, Sn-6.5Zn exhibited no melting range. Dipping and spreading tests were carried out to characterize the wettability of Sn-Zn alloys on Cu. Both tests exhibited that Sn-6.5Zn has significantly better wettability on Cu than Sn-9Zn. The reaction layers formed during the spreading tests were examined. When the Zn concentration fell between 2.5wt%-9wt%, two reaction layers were formed at the interface, a thick and flat Cu5Zn8 adjacent to Cu and a thin and irregular Cu-Zn-Sn layer adjacent to the alloy. Only a Cu6Sn5 layer was formed when the Zn concentration decreased to 0.5wt%. The total thickness of the reaction layer(s) between the alloy and Cu was found to increase linearly with the Zn concentration.
关键词:
lead-free solder
,
Sn-Zn合金
,
润湿性
,
界面
,
金属间化
高健
,
康健
,
吴学玲
,
徐競
,
李邦梅
,
邱冠周
中国有色金属学报
以分离于江西某铜矿的嗜铁钩端螺旋菌(L. ferriphilum YSK)菌株为研究对象,报道不同Fe2+浓度对 L. ferriphilum生长活性的影响.结果表明,YSK菌株生长最适宜的Fe2+浓度约为0.1 mol/L.当初始Fe2+浓度为0.4 mol/L时,进入对数生长期前很明显需要一个较长的延迟期,表明该Fe2+浓度对细胞的生长产生较强的抑制作用;当初始Fe2+浓度为0.6 mol/L时,YSK菌株的生长完全受到抑制.尽管高浓度的Fe2+抑制细胞的生长,但受到抑制而不生长繁殖的YSK细胞仍然具有氧化Fe2+的能力.
关键词:
L.ferriphilum YSK菌株
,
Fe2+
,
生长活性
