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Simulation of Solidification Parameters during Zr Based Bulk Metallic Glass Matrix Composite’s (BMGMCs) Additive Manufacturing

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Engineering（科研） 2018年第3期10卷 85-108页

作者： muhammad musaddique ali rafique School of Engineering [Aerospace Mechanical and Manufacturing Engineering] RMIT University Carlton Australia

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.

关键词： Simulation Metallic Glass Solidification Toughness

Modelling and Simulation of Solidification Phenomena during Additive Manufacturing of Bulk Metallic Glass Matrix Composites (BMGMC)—A Brief Review and Introduction of Technique

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Journal of Encapsulation and Adsorption Sciences 2018年第2期8卷 67-116页

作者： muhammad musaddique ali rafique School of Engineering (Aerospace Mechanical and Manufacturing) RMIT University City Campus Melbourne Australia

Despite a wealth of experimental studies focused on determining and improving mechanical properties and development of fundamental understanding of underlying mechanisms behind nucleation and growth of ductile phase precipitates from melt in glassy matrix, still, there is dearth of knowledge about how these ductile phases nucleate during solidification. Various efforts have been made to address this problem such as experiments in microgravity, high resolution electron microscopy and observation in synchrotron light after levitation but none have proved out to be satisfactory. In this study, an effort has been made to address this problem by modelling and simulation. Current state of the art of development, manufacturing, characterisation and modelling and simulation of bulk metallic glass matrix composites is described in detail. Evolution of microstructure in bulk metallic glass matrix composites during solidification in additive manufacturing has been presented with the aim to address fundamental problem of evolution of solidification microstructure as a result of solute partitioning, diffusion and capillary action. An overview is also presented to explain the relation of microstructure evolution to hardness and fracture toughness. This is aimed at overcoming fundamental problem of lack of ductility and toughness in this diverse class of materials. Quantitative prediction of solidification microstructure is done with the help of advanced part scale modelling and simulation techniques. It has been systematically proposed that 2-dimensional cellular automaton (CA) method combined with finite element (for thermal modelling) tools (CA-FE) programmed on FORTRAN? and parallel simulated on ABAQUS? would best be able to describe this complicated multiphysics phenomenon in most efficient way. Focus is laid on quantification of methodology by which modelling and simulation can be adopted and applied to describe evolution of microstructure in this important class of material

关键词： Solidification Modelling and Simulation Cellular Automaton

Production and Characterization of Zr Based Bulk Metallic Glass Matrix Composites (BMGMC) in the Form of Wedge Shape Ingots

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Engineering（科研） 2018年第4期10卷 215-245页

作者： muhammad musaddique ali rafique School of Engineering [Aerospace Mechanical and Manufacturing] RMIT University Queensbury Street Carlton Australia

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. Further, thermal analysis, optical microscopy and hardness measurement confirmed the formation and evolution of in-situcomposite structure. This is first footprint of pathway towards sustainable manufacturing of these alloys in future.

关键词： BMGMC as Cast Dendrite Ingot Toughness

Probabilistic Modelling of Microstructural Evolution in Zr Based Bulk Metallic Glass Matrix Composites during Solidification in Additive Manufacturing

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Engineering（科研） 2018年第4期10卷 130-141页

作者： muhammad musaddique ali rafique RMIT University-City Campus Carlton Australia

Bulk metallic glass and their composites (BMGMCs) are a new class of materials which possess superior mechanical properties as compared to existing conventional materials. Owing to this, they are potential candidates for tomorrow’s structural applications. However, they suffer from poor ductility and little or no toughness which render them brittle and they manifest catastrophic failure under applied force. Their behavior is dubious, unpredictable and requires extensive experimentation to arrive at conclusive results. In present study, an effort has been made to design bulk metallic glass matrix composites by the use of modeling and simulation. A probabilistic cellular automaton (CA) model is developed and described in present study by author which is used in conjunction with earlier developed deterministic model to predict microstructural evolution in Zr based BMGMCs in additive manufacturing liquid melt pool. It is elaborately described with an aim to arrive at quantitative relations which describe process and steps of operations. Results indicate that effect of incorporating all mass transfer and diffusion coefficients under transient conditions and precise determination of probability number play a vital role in refining the model and bringing it closer to a level that it could be compared to actual values. It is shown that proposed tailoring can account for microstructural evolution in metallic glasses.

关键词： Bulk Metallic Glass Matrix Composites Solidification Cellular Automata Method

Analytical Modeling and Computer Simulation of Heat Transfer Phenomena during Hydrothermal Processing Using SOLIDWORKS®

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Engineering（科研） 2020年第9期12卷 682-697页

作者： muhammad musaddique ali rafique Umair Shah Eastern Engineering Solutions LLC Detroit MI USA Law Chamber Muhammad Rafique (Advocate High Court Lahore Supreme Court of Pakistan) Nizamabad Kot Khawaja Saeed Lahore Pakistan University of Punjab Lahore Pakistan

Mathematical modeling of unit operations especially in biomaterials processing plays an important part in understanding simultaneous heat and mass transfer and fluid flow phenomena. Hydrothermal/supercritical processes are one such process which utilizes high temperature and pressure to synthesize materials for varied applications. The present study constitutes development of a model incorporating all standard transport equations and transient conditions to predict the behavior of process and thus materials upon heating to high temperature in an enclosed composite (Steel and Teflon (PFA) vessel. Commercial software package SOLIDWORKS® is employed to simulate and output is presented as animations after post-processing. Results yield very useful data and information about process;materials of construction and materials being processed which helps in optimization.

关键词： Hydrothermal Simulation TEFLON

Modeling and Simulation of Heat Transfer Phenomenon Related to Mold Heating during Investment Casting

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Engineering（科研） 2020年第5期12卷 291-314页

作者： muhammad musaddique ali rafique Umair Shah College of Engineering & Emerging Technologies University of the Punjab Lahore Pakistan.

Cast shape during investment casting process dictates properties and service life of the casting. These properties are the function of cast part parameters (both static and dynamic), part geometry and hence mold geometry, nature and type of metal being cast, properties (extrinsic and intrinsic) and processing parameters (rate of heating, rate of cooling, rate of pouring). Improper and inadequate manipulation and modification of mold properties degrade the properties and life of casting altogether. A mathematical model is developed using standard transport equations incorporating all heat transfer coefficients (HTCs) to determine the effect of external mold heating on the properties of the final casting and a simulation is performed in C++ to validate it against experimental results. Pure iron is casted in investment molds of silica sand with zircon coating. Airflow near the mold surfaces was partially restricted due to geometry of the molds and arrangement of the pieces around a tree. The variations in heat transfer coefficient contribute towards total heat transfer out of mold surface. External heating is found to be very effective for improved casting properties. The mold heat transfer profile is found to be in good agreement with experimental values validating the effectiveness of mold heating.

关键词： Investment Casting Mold HTC C++ Simulation

Production of Carbon Nanotubes by Different Routes-A Review

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Journal of Encapsulation and Adsorption Sciences 2011年第2期1卷 29-34页

作者： muhammad musaddique ali rafique Javed Iqbal 不详

Carbon Nanotubes are one the most important materials of future. Discovered in 1991, they have reached a stage of attracting the interests of many companies world wide for their large scale production. They possess remarkable electrical, mechanical, optical, thermal and chemical properties, which make them a perfect “fit” for many engineering applications. In this paper various methods of production of carbon nanotubes are discussed outlining their capabilities, efficiencies and possible exploitation as economic large scale production methods. Chemical vapor disposition (CVD) is proposed as a potential method for economic large scale production of carbon nanotubes due to its relative simplicity of operation, process control, energy efficiency, raw materials used, capability to scale up as large unit operation, high yield and purity.

关键词： Carbon Nanotubes Chemical Vapor Deposition (CVD) Unit Operation Yield

Effect of Inoculation on Phase Formation and Indentation Hardness Behaviour of Zr47.5Cu45.5Al5Co2and Zr65Cu15Al10Ni10Bulk Metallic Glass Matrix Composites

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Engineering（科研） 2018年第8期10卷 530-559页

作者： muhammad musaddique ali rafique Milan Brandt Mark Easton RMIT University Carlton VIC Australia

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. 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. A support is provided to hypothesis that inoculations remain successful in promoting phase formation and crystallinity and improving toughness.

关键词： Inoculation Crystallinity Phase Formation Toughness

Effect of Single Pass Laser Surface Treatment on Microstructure Evolution of Inoculated Zr47.5Cu45.5Al5Co2and Non-Inoculated Zr65Cu15Al10Ni10Bulk Metallic Glass Matrix Composites

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Engineering（科研） 2018年第10期10卷 730-758页

作者： muhammad musaddique ali rafique Milan Brandt Mark Easton Ivan Cole Sabu John School of Engineering RMIT UniversityMelbourneAustralia Additive Manufacturing Precinct RMIT UniversityMelbourneAustralia Advanced Manufacturing and Fabrication Enabling Capability Platform RMIT UniversityCity CampusMelbourneAustralia School of Engineering Cluster Manufacturing Materials and MechatronicsRMIT UniversityBundoora CampusMelbourneAustralia

Bulk metallic glass matrix composites are advocated to be material of future owing to their superior strength, hardness and elastic strain limit. However, they possess poor toughness which makes them unusable in any structural engineering application. Inoculation has been used as effective mean to overcome this problem. Zr47.5Cu45.5Al5Co2 bulk metallic glass matrix composites (BMGMC) inoculated with ZrC have shown considerable refinement in microstructure owing to heterogeneous nucleation. Efforts have also been made to exploit modern laser-based metal additive manufacturing to fabricate BMGMC parts in one step. However, the effect of laser on inoculated material is unknown. In this study, an effort has been made to apply single pass laser surface treatment on untreated and inoculated BMGMC samples. It is observed that laser treatment not only refine the microstructure but result in change of size, morphology and dispersion of CuZr B2 phase in base metal, heat affected zone and fusion zone in Zr47.5Cu45.5Al5Co2. A similar effect is observed for β-Zr and Zr2Cu in non-inoculated Zr65Cu15Al10Ni10. This effect is documented with back scatter electron imaging.

关键词： Additive Bulk Metallic Glass Composites Inoculation Phase