X-ray Study Of Pd_(40)Cu_(30)Ni_(10)P_(20) Bulk Metallic Glass Brazing Filler For Ti-6Al-7Nb Alloy

摘要

Crystalline precipitates in a bulk-metallic-glass (BMG) braze were investigated with an intense x-ray microbeam. The precipitates were found in the Pd_(40)Cu_(30)P_(20)Ni_(10) BMG braze matrix after joining crystalline Ti-6Al-7Nb. However, the role (if any) played by the precipitates in improving the mechanical bond of the BMG/crystalline joint is unknown. X-ray microdiffraction and microfluorescence measurements from small sample volumes were made with an ～ 0.5 × 0.5 μm~2 beam. Spatially-resolved Laue diffraction and x-ray fluorescence measurements were made on several second-phase crystals within the BMG matrix. Although precipitate crystals with the observed compositions were anticipated to be predominantly hexagonal, one of the crystals was found to be cubic or tetragonal. The instrumentation includes capabilities for 3D depth-resolved measurements of crystal structure and for fluorescence analysis of elemental composition. Depth profiling gave information about the grain distribution and morphology in the BMG matrix.