Vacuum brazed assemblies can be found in a wide array of markets and applications. These assemblies can range from oil coolers for automotive applications to highly complex environmental control systems with reduced weights for the aerospace and defense industries. The vacuum brazing process is especially ideal for products where high quality joints, lightweight assemblies and high thermal and mechanical performances are required.
Vacuum brazing is a manufacturing process for joining components that allows for higher thermal performance and lighter solutions. Braze alloys have a lower melting temperature than the materials that they are joining. Prior to the heating process, the braze alloy is applied between close fitting components of the parent alloy that are fixtured into place. The parts are placed in a vacuum furnace that is heated to at least 450°C, a level that will melt the braze alloy but not the main material. As the furnace is a vacuum environment, there is no risk of oxidation and no need for flux. The molten braze alloy fills in gaps between the components through capillary action so that when the part is cooled, it forms a joint through atomic attraction and diffusion. The end result is a clean, one-piece construction with strong joints.
Depending on application requirements of the part and its complexity, a helium leak check can verify the leak tightness of brazed joints. Parts that require T4 or T6 hardness stage undergo heat treatment after leak tight tests. This enables machining at similar feeds and speeds as those for untreated aluminum. Depending on individual part geometries, additional processes such as straightening may allow more effective ways of machining the finished components when required.
Although it can be limited by fixturing or oven size, vacuum brazing is an extremely versatile and clean process. As such, it tends to be the preferred manufacturing process used to produce lightweight, high performance assemblies with increased internal surface areas. Additionally, vacuum brazing can be used to produce larger assemblies with complex geometries, benefiting from the low distortion introduced by the process itself. These structures can range from plank type assemblies with internal channels to electronic enclosures, with or without internal features such as cold walls.
Vacuum Brazed Liquid Cold Plates
Vacuum Brazed Cold Plates are high performance cold plates that can be designed and fabricated with customized flow paths to meet or exceed a customer’s unique application requirements. Vacuum brazed liquid cold plates are typically milled plates with meso or micro channels and can include extended surfaces such as skived or folded fins to increase heat transfer. Vacuum brazing is a highly repeatable, flux free process leading to clean, consistent, FOD-free parts. Joints can be produced to near parent metal strength, leading to leak and void free parts with high proof pressures.
Aavid also specializes in Brazed Heat Exchangers, Heat Sinks, Chassis & Enclosures
BenefitsVacuum brazing offers significant benefits over other joining technologies: