Ni-Flex™ Braze ProductsExceptionally precise
Leaders in Thermal Processing
MDC Provides expert brazing options to meet the individual needs of customers worldwide. Brazing is one of the most versatile and economical methods of joining metal due to its superior strength and MDC has worked with industry leaders to create a new class of nickel based braze alloys in ductile foil and wire. This technology, based on the controlled diffusion of boron into metals, is the reason our brazed rings and foils result in a far superior product.
MDC starts by having a custom ingot cast with the precise composition to meet many widely used aerospace alloys. The ingot is drawn or rolled to the desired thickness, or shape and then BOROFUSE® processed. The resulting material has the appropriate composition with the newly added boron.
Borided Braze Foils – Ni-Flex
A boron-containing braze alloy such as AMS 4778 (3% B, 4.5% Si, Bal. Ni) is produced as foil in the boron free, ductile condition. The nickel-silicon foil is produced to the desired thickness (e.g., 0.002″) by conventional foil-making practices. Boron is then diffused into the surfaces to achieve an overall level of 3.0 weight percent. The boron is represented as borides throughout the diffused zone, while the core remains ductile. Foil produced in this manner displays excellent ductility due to the boron-free, ductile core. Pre-forms of the appropriate configuration can be produced from the foil by stamping and photo-etching.
Brazing cycles appropriate to the particular alloy are used in the bonding process, during which the entire foil melts, producing a homogeneous liquid of the filler metal. This method is used to produce fully dense, ductile braze foils of precisely controlled thickness. Braze alloys that can be produced include any of the boron-containing compositions which, in a boron free state, exhibit reasonable ductility. This includes, but is not restricted to, such widely used alloys as AMS 4775, 4776, 4777, 4778 and 4779.
Borided Braze Rings and Wire – Ni-Flex
In many applications, it is desirable to use wire pre-forms for diffusion brazing. For example, the placement of a wire ring for the joining of tubing is common practice. BOROFUSE processed braze rings and wire are superior to powder sintered braze preforms because of the ductile core of the wire or ring. The flexibility of the BOROFUSE processed rings and wire makes them a very robust solution to braze application and assembly of brazed parts.
The techniques described above are being used to produce fully dense, nickel-based braze wire. As with the foil, wire is drawn in the boron-free, ductile state. Pre-forms are then produced to any desired configuration. Boron is then diffused into the surfaces to achieve the proper finished braze composition. Brazing is carried out in the normal manner, consistent with the specific composition being used.