Diffusion welding of SiC Fiber-reinforced Aluminum- base Alloy Composite

An investigation has been made of the diffusion welding of SiC fiber-reinforced aluminum-base alloycomposite which is very difficult to join by the conventional fusion-welding technique。was made using Al-Cu-Mg series alloy （2017）2024 alloy) and Al-5%Ca alloy as insert-metals at 540 - C to 630 - C in 1x <10^(-4)> Torr. The rapidlycooled Al-5%Ca alloy foil, 10mm in width and 40-50 <mu> m thick，were produced by liquid quenching. From the experiment，following results are obtained.(1) A higher bond strength for the Al-Al weldment is obtained by(2) The projection of SiC fiber on The welding surface is caused by Theelectrolytic polishing. The projecting fibers play an important role in improvement of tensile andbend strength of the joint.(3) Diffusion welding of Al to FRM using 2017 and 2024 alloy foils havebeen caried out in the temperature range above the solidus line where solid and liquid phasescoexist. The maximum tensile strength was obtained when The volume fraction of The liquid phase(4) The weldments made with Al-5%Ca alloy foil at The welding temperature of 630 - C for 180 minhave the maximum tensile strength. This is attributable to acceleration of the interface reaction经典fiber and Al matrix by Ca。

An investigation has been made of the diffusion welding of SiC fiber-reinforced aluminum-base alloy composite which is very difficult to join by the conventional fusion-welding technique. The welding was made using Al-Cu-Mg series alloy (2017, 2024 alloy) and Al-5%Ca alloy as insert-metals at 540゜C to 630゜C in 1x <10^(-4)> Torr. The rapidly cooled Al-5%Ca alloy foil, 10 mm in width and 40-50 <mu> m thick, were produced by liquid quenching. From the experiment, the following results are obtained.(1) A higher bond strength for the Al-Al weldment is obtained by using electrolytic polishing.(2) The projection of SiC fiber on the welding surface is caused by the electrolytic polishing. The projecting fibers play an important role in improvement of tensile and bend strength of the joint.(3) Diffusion welding of Al to FRM using 2017 and 2024 alloy foils have been caried out in the temperature range above the solidus line where solid and liquid phases coexist. The maximum tensile strength was obtained when the volume fraction of the liquid phase was 1-5%.(4) The weldments made with Al-5%Ca alloy foil at the welding temperature of 630゜C for 180 min have the maximum tensile strength. This is attributable to acceleration of the interface reaction between SiC fiber and Al matrix by Ca.