NUST Institutions Library Catalogue

Diffusion bonding is a solid-state joining technique that fuses two materials together by applying
pressure and heat. The atoms from one material diffuse into the other as a result of the high pressure
and temperature, joining the two materials together. The diffused atoms form bond interface.
Diffusion bonding is a desirable option for applications that call for high strength, because the
bond formed is extremely durable and resistant to fracture. Plates of High Strength Low Alloy
Steel (HSLA) were successfully bonded by diffusion bonding process with interlayer of Beryllium
Copper between them. Beryllium copper alloys produces a bond that is both strong and thermally
stable, which makes it suitable for high-temperature applications. Research on diffusion bonding
is being done to optimize the diffusion bonding variables to achieve maximum tensile strengths.
The strength was achieved at temperatures, 750°C, 800°C and 850°C for hold time 1hr 2hr and
3hr under the pressure of 20Mpa. Prior to the bonding process, the materials need to be cleaned
and properly prepared in order to achieve successful diffusion bonding. This involves eliminating
any contaminants and surface flaws that might adversely affect the bond. In this study samples
were first cleaned by ethanol in ultrasonic cleaner for 30 minutes, secondly the samples are grinded
on different emery papers ranging from p240, p600, p800, p1000, p1500, p2000 to achieve smooth
even surface. Diffusion bond interface has been analyzed by scanning electron microscopy (SEM)
to check the interface of joined plates. X-Ray diffraction (XRD) technique is used to determine
the internal stresses.