The Soldering Process Can Be Easily Automated Offering The Possibility Of
Mass soldering by wave, drag, or dip machines has been the preferred method for making high-quality, reliable connections for many decades. Despite the appearance of new connecting systems, it still retains this position. Correctly controlled, soldering is one of the least expensive methods for fabricating electrical connections. Incorrectly controlled, it can be one of the most costly processes--not because of the initial cost, but because of the many far-reaching effects of poor workmanship....
Flux Classification
Fluxes can be categorized depending on the method of manufacture, the extent to which they can affect the alloy content of the weld deposit, and the effect on weld deposit properties. Classification Relative to Production Method. Based on the manufacturing process, there are two different types of fluxes fused and bonded. Fused Fluxes. The raw materials for a fused flux are dry mixed and melted in a furnace. The molten mixture is then rapidly solidified, crushed, screened, and packaged. Because...
Bonding Surfaces Containing Oxides
Diffusion bonding can be achieved for materials with adherent surface oxides, but the resultant interface strengths of these materials are considerably less than that measured for the parent material. Aluminum alloys are prime examples of this class of material. Research since 1960 has demonstrated only limited diffusion bond properties. Although interface strength can be increased for oxide-bearing materials, it requires considerable surface extension of the faying interfaces to create...
Solidification Cracking Hot Cracking
Hot cracks are solidification cracks that occur in the fusion zone near the end of solidification. Simplistically, they result from the inability of the semisolid material to accommodate the thermal shrinkage strains associated with weld solidification and cooling. Cracks then form at susceptible sites to relieves the accumulating strain. Susceptible sites are interfaces, such as solidification grain boundaries and interdendritic regions, that are at least partially wetted. Figure 1 is a...
References cited in this section Ipi
28. F.R. DEBOER, R. BOOM, W.C.M. MATTENS, A.R. MIEDEMA, AND A.K. NIESSEN, COHESION IN METALS TRANSITION METAL ALLOYS, NORTH-HOLLAND, 1989 41. N. MARTENSSON, A. STENBORG, O. BJORNEHOLM, A. NILSSON, AND J.N. ANDERSON, QUANTITATIVE STUDIES OF METAL-METAL ADHESION AND INTERFACE SEGREGATION ENERGIES USING PHOTOELECTRON SPECTROSCOPY, PHYS. REV. LETT., VOL 60 NO. 17 , APRIL 1988, P 1731-1734 42. J.N. ANDERSON, O. BJORNEHOLM, A. STENBORG, A. NILSSON, C. WIGREN, AND N. MARTENSSON, MEASUREMENT OF...