US EPA

540301 

Journal Article 

Effect of Nd and La on surface tension and wettability of Sn-8Zn-3Bi solders 

Zhou, J; Sun, YS; Xue, F 

2005 

1 

Transactions of Nonferrous Metals Society of China
ISSN: 1003-6326 

15 

5 

1161-1165 

English 

Maximum bubble pressure measurement was employed to evaluate surface tension of Sn-8Zn-3Bi-(0-0.15) Nd and Sn-8Zn-3Bi- (0-0.15) La solder melts. Wetting balance method was used to measure wetting force and wetting time on Cu substrate of the two group solders. The experimental results show that minute amount of Nd or La addition to Sn-8Zn-3Bi solder causes significant decrease of the surface tension of the solder melts at 200-240 degrees C and Nd addition is more effective on reduction of surface tension than that of La. Nd or La addition has the effect on enhancing the wetting force of the solder melts on Cu substrate! which results from the decrease of interfacial tension between the solder melt and Cu substrate. The wetting force reaches the maximum when 0.1% Nd is added to the base alloy. The contact angle between Sn-8Zn-3Bi base solders and Cu substrate decreases with the addition of Nd or La and the minimum of the contact angle is obtained from the solder with 0.1% Nd addition. 

lead-free solder; zinc; neodymium; lanthanum; surface tension; wettability