Autor: FELIPE DE JESUS GARCIA VAZQUEZ
Transient liquid phase (TLP) bonding of 304 stainless steel with nickel based filler metal, BNi-9, was performed to
study the influence of silicon nanoparticles (NPs) on the mechanical and structural properties of the bonding area.
It was found that silicon NPs act as a melting point depressant in the brazing process; the formation of silicon TLP
induces the dissolution of elements of the metal filler and promotes a uniform distribution in the bonding area.
Silicon NPs induce the development of smaller eutectic structures in the melting zone; it has been related to
microhardness measurements, which are lower when the silicon NPs are used in the brazing process.
Aluminum/Graphite composites (Al/C composites) have the advantages of Al (light weight, easy
machinability and good heat conduction) in combination with the advantages of C whiskers (High
Youngs Modulus, small to negative CTE, high tensile strength and high thermal conductivity).
However, Metallographic analysis, EDX and microhardness profile revealed that fibers react with
molten aluminum to form the detrimental Al4C3 phase in the HAZ and fusion zone. In order to gain
information about temperature transformation and formation conditions, scanning electron microscopy,
and termochemistry analysis were used. For experiments, were used power density (I), pulse width (t),
frequency (F), travel speed (S) and filler material (M) as independent variables. Thereby, was found
that the main process variables that influence the formation of Al4C3 are pulse duration and welding
speed, and that the effect of these variables cannot be explained only by using a thermodynamic model,
requiring a subsequent kinetic analysis.
Capítulo de libro