Vacuum Brazing of 55 vol.% SiCp/ZL102 Composites Using Micro-Nano Brazing Filler Metal Fabricated by Melt-Spinning

Dechao Qiu,Xianli Ba,Zeng Gao,Jitai Niu,Zhenjiang Wang

doi:10.3390/met10111470

Dechao Qiu, Xianli Ba + Show 3 more

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https://doi.org/10.3390/met10111470

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Abstract

The joining methods of Aluminum matrix composites reinforced with SiC particles (SiCp/Al MMCs) are a challenge during the manufacturing process due to the significant differences between SiC particles and base aluminum in terms of both physical and chemical properties. Micro-nano brazing filler metal Al-17.0Cu-8.0Mg fabricated by melt-spinning technology was employed to deal with the joining problem of 55 vol.% SiCp/ZL102 composites in this work. The result indicated that the foil-like brazing filler metal contained uniformed cellular nano grains, with a size less than 200 nm. The solidus and liquidus temperatures of the foil-like brazing filler metal decreased by 4 °C and 7 °C in comparison with the values of the as-cast brazing filler metal due to the nanometer size effect. The maximum joint shear strength of 98.17 MPa achieved with a brazing temperature of 580 °C and holding time of 30 min was applied in vacuum brazing process. The width of the brazing seam became narrower and narrower with increasing brazing temperature owning to the strong interaction between the micro-nano brazing filler metal and 55 vol.% SiCp/ZL102 composites. The fracture morphology of the joint made at a brazing temperature of 580 °C was characterized by quasi-cleavage fracture. After brazing, the chemical concentration gradient between the brazing filler metal and base material disappeared.

Highlights

Aluminum matrix composites reinforced with SiC particles (SiCp /Al MMCs) have attracted more and more attention from researchers around the world because of their excellent performances such as high specific stiffness and specific strength, low thermal expansion coefficient, good radiation resistance, and so on [1,2,3,4]
The results showed that owing to its small size and high surface free energy, the surface free energy, the chemical potential of the foil-like brazing filler metal containing micro-nano cooling rate
The results showed that owing to its small size and high surface free energy, the chemical potential of the foil-like brazing filler metal containing micro-nano grains was much higher grains was much higher thatbrazing of the bulk

Summary

Introduction

Aluminum matrix composites reinforced with SiC particles (SiCp /Al MMCs) have attracted more and more attention from researchers around the world because of their excellent performances such as high specific stiffness and specific strength, low thermal expansion coefficient, good radiation resistance, and so on [1,2,3,4]. SiCp /Al MMCs are favored in the field of electronic packaging due to their high dimensional stability and thermal conductivity. At present, joining methods of SiCp /Al MMCs mainly focus on fusion welding [13,14,15], diffusion welding [16,17], and brazing [18,19,20].

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