Emphasizing on Production and Characterization of Zr Based Bulk Metallic Glass Matrix Composites (BMGMC) in the Form of Wedge Shape Ingots | Chapter 7 | Recent Developments in Engineering Research Vol.4

 

Bulk metallic glass matrix composites (BMGMC) are unique materials of future having excellent
mechanical properties (such as high hardness, strength and profound elastic strain limit). However,
they exhibit poor ductility and suffer from catastrophic failure on the application of force. The reasons
behind this are still not very well understood. In this study, an effort has been made to overcome this
pitfall by solidification processing. Zr based BMGMCs are produced in the form of “as cast” wedges
using vacuum arc melting and suction casting button furnace. The idea is to study the effect of cooling
rate and inoculation on formability during solidification. Adjustment, manipulation and proper control of
processing parameters are observed to reflect upon the quality of ingots such as improved castability,
proper mold filling and defect free casting as characterized by NDT. Bulk metallic glass matrix
composites (BMGMC) are very sluggish and difficult to cast alloys. Vacuum melting and suction
casting is effective way to fabricate these alloys. However, extremely careful control and monitoring of
process variables is needed to form these alloys in good shape. Further, thermal analysis, optical
microscopy and hardness measurement confirmed the formation and evolution of in-situ
composite structure. This is first footprint of pathway towards sustainable manufacturing of these
alloys in future.

Author (s) Details
Muhammad Musaddique Ali Rafique
Eastern Engineering Solutions LLC, Detroit, MI, USA.

View Book :- https://bp.bookpi.org/index.php/bpi/catalog/book/263

Research on the Simulation of Solidification Parameters during Zr Based Bulk Metallic Glass Matrix Composite’s (BMGMCs) Additive Manufacturing | Chapter 6 | Recent Developments in Engineering Research Vol.4

 

After a silence of three decades, bulk metallic glasses and their composites have re-emerged as a
competent engineering material owing to their excellent mechanical properties not observed in any
other engineering material known till date. However, they exhibit poor ductility and little or no
toughness which make them brittle and they fail catastrophically under tensile loading. Exact
explanation of this behaviour is difficult, and a lot of expensive experimentation is needed before
conclusive results could be drawn. In present study, a theoretical approach has been presented aimed at solving this problem. A detailed mathematical model has been developed to describe solidification phenomena in zirconium based bulk metallic glass matrix composites during additive manufacturing. It precisely models and predicts solidification parameters related to microscale solute diffusion (mass transfer) and capillary action in these rapidly solidifying sluggish slurries. Programming and simulation of model is performed in MATLAB®. Results show that the use of temperature dependent thermophysical properties yields a synergic effect for multitude improvement and refinement simulation results. Simulated values proved out to be in good agreement with prior simulated and experimental results. There is significant effect of initial metal temperature, composition, type of alloying elements,temperature gradient and thermo-physical properties on final microstructure developed as a result of heat and mass transfer phenomena.

Author (s) Details

Muhammad Musaddique Ali Rafique
Eastern Engineering Solutions LLC, Detroit, MI, USA.

View Book :- https://bp.bookpi.org/index.php/bpi/catalog/book/263

Emphasizing on Production and Characterization of Zr Based Bulk Metallic Glass Matrix Composites (BMGMC) in the Form of Wedge Shape Ingots | Chapter 7 | Recent Developments in Engineering Research Vol.4

 

Bulk metallic glass matrix composites (BMGMC) are unique materials of future having excellent
mechanical properties (such as high hardness, strength and profound elastic strain limit). However,
they exhibit poor ductility and suffer from catastrophic failure on the application of force. The reasons
behind this are still not very well understood. In this study, an effort has been made to overcome this
pitfall by solidification processing. Zr based BMGMCs are produced in the form of “as cast” wedges
using vacuum arc melting and suction casting button furnace. The idea is to study the effect of cooling
rate and inoculation on formability during solidification. Adjustment, manipulation and proper control of
processing parameters are observed to reflect upon the quality of ingots such as improved castability,
proper mold filling and defect free casting as characterized by NDT. Bulk metallic glass matrix
composites (BMGMC) are very sluggish and difficult to cast alloys. Vacuum melting and suction
casting is effective way to fabricate these alloys. However, extremely careful control and monitoring of
process variables is needed to form these alloys in good shape. Further, thermal analysis, optical
microscopy and hardness measurement confirmed the formation and evolution of in-situ
composite structure. This is first footprint of pathway towards sustainable manufacturing of these
alloys in future.

Author (s) Details
Muhammad Musaddique Ali Rafique
Eastern Engineering Solutions LLC, Detroit, MI, USA.

View Book :- https://bp.bookpi.org/index.php/bpi/catalog/book/263

Estimation of Inoculation Effect on Phase Formation and Indentation Hardness Behaviour of Zr47.5Cu45.5Al5Co2 and Zr65Cu15Al10Ni10 Bulk Metallic Glass Matrix Composites | Chapter 8 | Recent Developments in Engineering Research Vol.4

 

The present study aimed to explain and understand the phenomena of nucleation and growth in these
alloys as a function of percentage of inoculant and cooling rate while later varies with change of point
of observation along wedg. Bulk metallic glass matrix composites have emerged as a new potential
material for structural engineering applications owing to their superior strength, hardness and high
elastic strain limit. However, their behaviour is dubious. They manifest brittleness and inferior ductility
which limit their applications. Various methods have been proposed to overcome this problem. With
the help of energy dispersive X-ray spectroscopy (EDS) detector, it can also generate map of crystal
structure of individual elements which can help identify their nature and microstructural features (e.g.
primary, secondary and tertiary dendrite arm spacing). Out of these, introduction of foreign particles
(inoculants) during solidification has been proposed as the most effective. In this study, an effort has
been made to delimit this drawback. A systematic tale has been presented which explains the
evolution of microstructure in Zr47.5Cu45.5Al5Co2 and Zr65Cu15Al10Ni10 bulk metallic glass matrix
composites with varying percentage of ZrC inoculant as analysed by secondary electron, back scatter
electron imaging of “as cast” unetched samples and indentation microhardness testing. Secondary
electron imaging of indents was also performed which shows development of shear transformation
zones at edges of square of indents. Mostly, no cracking was observed, few cracks bearing Palmqvist
morphology were witnessed in samples containing lower percentage of inoculant. It is also observed
experimentally that inoculation has a certain minimum threshold value (0.5%) till which it shows its
maximum effectivity (increase in toughness) and beyond which a balance, decrease and then
increase in toughness is observed. A support is provided to hypothesis that inoculations remain
successful in promoting phase formation and crystallinity and improving toughness.

Author (s) Details

Muhammad Musaddique Ali Rafique
Eastern Engineering Solutions LLC, Detroit, MI, USA.

View Book :- https://bp.bookpi.org/index.php/bpi/catalog/book/263