The soldering aluminum alloys containing high amounts of Mg with aid of ultrasonic vibration

众所周知，含有大量镁的铝合金是不可能焊接的。本研究是为了使钎焊成为可能并获得高强度的接头而进行的，在纯铝在无焊剂气氛中的超声振动钎焊已获得成功的基础上，我们尝试将超声振动应用于含镁难钎焊铝合金。使用纯锌金属，接头的抗拉强度达到约160 MPa。这种强度大约是基体金属的50%，是不够的.通过对钎焊层的详细观察，发现存在大量的镁夹杂物，这些夹杂物是由于母材的溶解造成的，断裂的路径是沿着这些夹杂物，并认为镁夹杂物的形成是降低接头抗拉强度的有害因素。 ...更多信息 用EPMA、AES和ESCA分析表明，加热使镁偏析在结合面上，从而导致镁夹杂物的形成。根据分析，采取了以下对策以提高接头强度。也就是说，增加加热速率以抑制镁偏析，并且使用Zn-Al-Si合金的填充金属以减少基底金属的溶解，并且增加填充金属本身的强度。结果，母材的溶解得到一定程度的抑制，但接头抗拉强度提高不够，我们再次选择纯锌箔作为钎料，并研究了通过快速加热抑制锰偏析和凝固组织控制晶粒细化来提高接头抗拉强度的可能性。这些措施成功地提高了含镁2.5%的铝合金的接头抗拉强度，并将这种超声振动钎焊方法应用于工业试件。不幸的是，由于在传递超声波振动时的损失，焊接面积约为接合面积的60%，因此接头强度不足。少

has been well known that the aluminum alloys containing a large amount of magnasium was impossible tobe soldered, so far. This study was carried out to make the soldering possible and to obtain the joints with higher sttrength introducing ultrasonic vibration into the soldered layrs.Since we have been successful in soldring the pure aluminum in atmosphere withou flux by using ultrasonic vibration, we tried to apply to the aluminum alloy containing magnasium difficult to be solderd with the aid of ultrasonic vibration. Using pure zinc metal, the joint of the tensile strength of approximately 160MPa was achieved. This strength is of about 50 % of a base metal, is not so sufficient. The detailed observation of soldered layr revealed that many Mg-inclusions ascribed to the dissolution of basemetal existed and the fracture path was along these inclusions, and it is expected that the formation of Mg-inclusions are the harmful factors to decrease the tensile strength of the joints.It was anal … More yzed with EPMA,AES and ESCA that magnasium was segregated onto the faying surface by heating, followed by causing the formation of the Mg-inclusions. Based on the analysis, the following countermeasure was adopted to increase the joint strength. That is, the heating rate was increased to suppress the magnesium segregation, and the filler metal of Zn-Al-Si alloy was used to decrease the dissolution of the base metal, and to increase the strength of a filler metal itself. As a result, the dissolution of the base matel was suppressed to some extent, but the joint tensile strength was insufficiently increrased.We selected again the pure zinc foil as a filler metal and examined the possibility to increase the joint tensile strenght through the grain refinement by solidifying structure control in addition to the suppression manganese segregation by rapid heating. These countermeasures increased successfully the joint tensile strength of the aluminum alloy containning Mg of 2.5% over the base metal strength.This new soldering method using ultrasonic vibration was applied to the commercially sized specimens. Unfortunately, the jointstrength was insufficient because the soldered area was of about 60% in the faying area due to the loss in transferring the ultrasonic vibration. Less