Study On The Electrodeposition Of Tin-Bismuth Alloy Using Ultrasound

Electrodeposition or electroplating is adopted to deposit metal layer in the metal surface for the sake of surface function that changes solid material or making the metal material take particular composition with function. Because the electrodeposits have good adhesion, the crystallize is small but again uniform, and can acquire the good physical and chemical functions. It is usually used for protection, decoration and satisfying the other special requests. And electrodeposits are very widely applied in machine, electronics, automobile, national defense, and aviation industry etc.Products with pure Tin deposits are widely used in electronics industry and light industry. For many years, many domestic and international electrochemistry scholars have studied on the acidity Tin electrodeposition. Because the shining Tin deposits obtained from acidic aqua have many advantages such as quick depositing speed, good solderability, better corrosion-resistance and etc. Up to now, the method is still extensively applied in production. The shining Tin-Bismuth alloy that obtained from acid electrolyte has many advantages. Such as compact structure, few holes, better resistance to oxidation and etc. Especially the solderability is very ideal. Thus, it is prospected to substitute solderable Tin. But to get satisfactory layers, the function of the additive is one of the key factors. In this paper, a kind of multi-functional additive was prepared, which can get at the same time the functions of shine, disperse and stabilization. The results show that the deposits are good: The crystallite is small; the deposits are shine with better corrosion resistance and solderability. Also,the operation process is simplified. The electrolyte is easy for maintenances and manages. And it is stable. Ultrasound has the characters of cavitation effect, machine effect and hot effect. In the electrodeposition process, these effects raise functions of cleaning function, removing hydrogen function and agitation function etc. Combining the character of ultrasound together with electrodeposition process produced special results. The photograph of SEM and the XRD diagram of the sample showed that the depositswere more compact and uniform. The tests of the solderability, high or low temperature stability and corrosion resistance showed that these were better than the functions of pure Tin deposits. The grid spectrum method was adopted to analyze the composition. It showed that the ultrasound influenced and changed the composition of the deposits. The tests of the electrolyte character showed that the ultrasound accumulated the depositing speed and increased the cathode current efficiency. And they both increased with the power, which resulted from that the ultrasound had accelerated the electrode process. The function of ultrasound still consisted in widely opening current density scope and temperature scope. And the other machine agitation in the operation could be saved. As a result again the operating terms were improved and excellently changed. Moreover, the quantity of the additive was obviously enlarged because of the effect of ultrasound.In fine, the mechanism of Tin-Bismuth alloy electrodeposition was simply discussed. the polarize curves and the volt-ampere circulate curves showed that in the Tin-Bismuth alloy depositing process, the affiliation of the additive with ultrasound for getting involved both made cathode polarizations increase, changed electrode process, and made crystallite grow better. Also the results of the XRD tests of the samples prepared in different terms showed that the deposits have excellent construction. The crystallites are more meticulous and the adhesion is better which made the corrosion-resistance and deposits solderability become better. This kind of operation method is simple and easy. Reforms to the traditional methods are easy too. Therefore, it has the actual applied value with foreground.