M4 Aluminum Joining Technology

Project Summary This project proposes development and a feasibility research of a novel metal joining technology encompassing soldering and brazing. This innovative technology will enable better joint integrity by creating an efficient capillary flow of molten metal only in the desired directions (i.e., not in all possible directions, as in traditional applications). This can be achieved through a modification of the surface micro-morphology, either by imposing a well organized surface roughness (a system of grooves of various topological features), or through a presence of surface modifications (like in case of enhanced isotropic surface roughness in preferential directions). An objective of such a capillary delivery of filler metal may involve difficult-to-approach micro zones of prospective joints. This aspect of the proposed technological novelty may also enhance traditional technological solutions (say, by assisting traditional brazing and soldering technologies). This would be important in particular in cases when demanding designs of mating surfaces hamper joint formation. So, the proposed approach would resolve significant obstacles in formation of good integrity joints: (1) in new macro/meso mechanical manufacturing (~) joining (for cases when local joint formation must not be exposed to filler metal-substrate interactions prior to joint formation, inherently present in traditional joining), and (2) in existing state-of-the-art brazing technologies (for example, aluminum controlled atmosphere brazing, CAB, or vacuum brazing) or soldering (in situations when poor joint formation may be caused by tight design requirements). Industrial applications may include micro/mezzo thermal devices, compact heat exchanger designs for automotive applications of aluminum in automotive industry, and/or applications for micro-fabrication (M4). Hence, successful implementation of investigated emerging technology may have a broad impact for Kentucky as a state nurturing aluminum, automotive and micro-fabrication industries and technologies.