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Title: X-ray study of Pd 40Cu 30Ni 10P 20 bulk metallic glass brazing filler for Ti-6Al-7Nb alloy

Abstract

Crystalline precipitates in a bulk-metallic-glass (BMG) braze were investigated with an intense x-ray microbeam. The precipitates were found in the Pd{sub 40}Cu{sub 30}P{sub 20}Ni{sub 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 {approx} 0.5 x 0.5 {micro}m2 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.

Authors:
 [1];  [2];  [2];  [2];  [3];  [1];  [3]
  1. Nagasaki University, Nagasaki, Japan
  2. ORNL
  3. Tohoku University, Japan
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
978716
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Science Forum; Journal Volume: 539-543
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALLOYS; BRAZING; CRYSTAL STRUCTURE; DIFFRACTION; DISTRIBUTION; FILLERS; FLUORESCENCE; GLASS; MORPHOLOGY

Citation Formats

Miura, E., Ice, Gene E, Specht, Eliot D, Pang, Judy, Kato, H., Hisatsune, K., and Inoue, I. X-ray study of Pd40Cu30Ni10P20 bulk metallic glass brazing filler for Ti-6Al-7Nb alloy. United States: N. p., 2007. Web. doi:10.4028/www.scientific.net/MSF.539-543.1983.
Miura, E., Ice, Gene E, Specht, Eliot D, Pang, Judy, Kato, H., Hisatsune, K., & Inoue, I. X-ray study of Pd40Cu30Ni10P20 bulk metallic glass brazing filler for Ti-6Al-7Nb alloy. United States. doi:10.4028/www.scientific.net/MSF.539-543.1983.
Miura, E., Ice, Gene E, Specht, Eliot D, Pang, Judy, Kato, H., Hisatsune, K., and Inoue, I. Mon . "X-ray study of Pd40Cu30Ni10P20 bulk metallic glass brazing filler for Ti-6Al-7Nb alloy". United States. doi:10.4028/www.scientific.net/MSF.539-543.1983.
@article{osti_978716,
title = {X-ray study of Pd40Cu30Ni10P20 bulk metallic glass brazing filler for Ti-6Al-7Nb alloy},
author = {Miura, E. and Ice, Gene E and Specht, Eliot D and Pang, Judy and Kato, H. and Hisatsune, K. and Inoue, I.},
abstractNote = {Crystalline precipitates in a bulk-metallic-glass (BMG) braze were investigated with an intense x-ray microbeam. The precipitates were found in the Pd{sub 40}Cu{sub 30}P{sub 20}Ni{sub 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 {approx} 0.5 x 0.5 {micro}m2 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.},
doi = {10.4028/www.scientific.net/MSF.539-543.1983},
journal = {Materials Science Forum},
number = ,
volume = 539-543,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Crystalline precipitates in a bulk-metallic-glass (BMG) braze were investigated with an intense x-ray microbeam. The precipitates were found in the Pd{sub 40}Cu{sub 30}P{sub 20}Ni{sub 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 {approx} 0.5 x 0.5 {micro}m2 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 predominantlymore » 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.« less
  • Due to their scientific significance and potential engineering applications, bulk metallic glasses are among the most intensively studied advanced materials. Understanding the glass-forming ability (GFA) of these metallic alloys is a long-standing subject. While a large number of empirical factors have been proposed to correlate with GFA of the alloys, a full understanding of GFA remains a goal to achieve. Since glass formation is a competing process against crystallization, we have performed a systematic analysis on the crystallization kinetics of two known best metallic glass-formers Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} (in at. %) and Zr{sub 41.2}Ti{sub 13.8}Cu{sub 12.5}Ni{sub 10}Be{sub 22.5}more » based on classical nucleation and growth theory. Our results show that there is a dramatic difference between the two alloys in their nucleation behavior although they possess comparable GFA. Particularly, an extremely sharp nucleation peak ({approx}10{sup 18}/m{sup 3} s) is found for Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} around 632 K with a very small half maximum width of 42 K, implying that this alloy is an excellent candidate for nanocrystallization studies. Moreover, we have also found that the GFA of these alloys can be calculated to a high accuracy and precision based on the classical theory, suggesting that the classical theory may be sufficient to account for glass formation mechanism in these metallic alloys.« less
  • Core-level photoemission spectroscopy and anomalous x-ray scattering (AXS) measurements were performed for the Pd{sub 42.5}Ni{sub 7.5}Cu{sub 30}P{sub 20} (PNCP) excellent metallic glass to investigate the chemical nature and local atomic structure, and the results were compared to those in Pd{sub 40}Ni{sub 40}P{sub 20} and Pd{sub 40}Cu{sub 40}P{sub 20}. The P 2p core levels clearly separate into two states, indicating that the P atoms have two different chemical sites, which is a strong experimental proof for the existence of an elastic inhomogeneity. From the AXS close to the Pd K edge, a specific Pd-P-Pd atomic configuration was observed, which is relatedmore » to the stable state in the P 2p core levels. All of the core levels measured in PNCP have the deepest binding energies among these glasses, indicating the most stable electronic states. Local structure around the P atoms is discussed by the AXS data and a metastable crystal appeared in a supercooled metallic alloy close to PNCP.« less
  • Isothermal crystallization studies were performed on the bulk glass forming alloy Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} in the undercooled liquid region between the glass transition and liquidus temperature, resulting in a complete time-temperature-transformation (TTT) diagram for crystallization. The TTT diagram shows a typical ''C'' shape with the nose at 50 s and 680 K. Assuming steady state nucleation and a diffusion-controlled growth rate, the TTT diagram was successfully fit over the entire range of the measurement. The microstructure after isothermal crystallization shows a modulation in Cu and P for all degrees of undercooling. The primary solidified phase is Cu{sub 3}Pd,more » which forms distinct dendrites at low undercooling. From additional constant cooling experiments, the critical cooling rate to bypass crystallization was determined to be 0.33 K/s. (c) 2000 American Institute of Physics.« less
  • Isothermal kinetics of relaxation of the high-frequency (1.4 MHz) shear modulus during structural relaxation of Pd{sub 40}Cu{sub 30}Ni{sub 10}P{sub 20} bulk metallic glass below the glass transition temperature is studied by an in situ method of contactless electromagnetic acoustic transformation. The kinetic law of relaxation is established. It is shown that quenching of aged samples from the supercooled liquid state leads to a decrease in the absolute value of shear modulus to below the initial value; the degree of subsequent isothermal relaxation of the modulus may be several times higher than the initial value. Possible reasons for relaxation and recoverymore » of the shear modulus are considered.« less