Metallic Glass Matrix Composites Research Articles

Different phase transformation behaviors of B2-CuZr crystalline phase and their associated mechanical properties by molecular dynamics using different potentials

Metastable CuZr-based alloys have attracted much attention due to their high glass-forming ability and shape memory effect. Many experiments have underscored the pivotal role of the B2-CuZr phase as an effective inclusion to improve both the strength and ductility of metallic glass matrix composites. The improved ductility can be attributed to the dilatation induced by martensitic transformation, while the strengthening effect is owed to the higher strength and hardness of the martensite phase compared to the austenite phase. Well-designed atomistic simulations can predict the mechanical behavior of materials before experiments and offer sufficient information on the atomic scale. The selection of an appropriate interatomic potential is a primary concern in any atomistic simulation and needs to be carefully considered to ensure reliable results. The uniaxial tensile behavior of B2-CuZr crystalline phase is investigated by molecular dynamics simulations using five typical potentials, namely the potentials developed by Mendelev-2007, Mendelev-2009, Mendelev-2016, Mendelev-2019 and Cheng-2009. The phase transformation behavior during tension, Young’s modulus, and yield strength of the simulated samples exhibit variations when different potentials are employed. Notably, only by employing Mendelev-2019 and Cheng-2009 potentials, the strength and Young’s modulus of the transformed phase are higher than the untransformed austenite phase, corresponding well with experimental results. This work emphasizes the impact of different interatomic potentials on phase transformation behaviors within a specific simulation context.

Effect of cooling rate during solidification on structure and mechanical properties of Cu45Zr48Al7 glass-forming alloy

The CuZr-based bulk metallic glass matrix composites have attracted great attention in recent years owing to their unique mechanical properties compared to bulk glassy samples. The vital effect of B2 CuZr phase on mechanical properties was previously confirmed in CuZr-based alloys with equiatomic concentrations of copper and zirconium. In this paper, the structures and mechanical properties of the Cu45Zr48Al7 alloy, which has hypereutectoid composition with respect to stoichiometric B2 CuZr phase, were studied. This alloy exhibits high glass-forming ability, but low tendency to form the B2 CuZr phase during solidification. However, we demonstrated that depending on the cooling rate during solidification, governed by sample diameter, either bulk metallic glass or bulk metallic glass matrix composite can be produced. In order to allow partial crystallization of the B2 phase during solidification with the volume fraction allowing to observe the strain hardening effect, the minimum cooling rate should be lower than 40 K/s. The composite consisting of a glassy outer layer and a crystalline core composed of the B2 phase exhibits fracture strength of the same level as the bulk glassy sample (above 1800 MPa) obvious work-hardening with a plastic deformation of about 6%.

Effect of geometry of crystalline dendrite on the uniaxial tension behavior of metallic glass matrix composites based on molecular dynamics simulations

Introducing crystalline dendrites can effectively enhance the plasticity of metallic glass matrix composites. The geometry (e.g., shape and orientation) of the crystalline dendrites can significantly influence the mechanical properties of the material. In this study, we create numerical Cu-Zr glassy samples containing crystalline dendrites of realistic geometries and study their mechanical behaviors under uniaxial tension loading through large-scale molecular dynamics simulations. The results indicate that shear band formation is sensitive to the shape and orientation of the dendrites. The geometry of the dendrites significantly affects the behavior of shear bands in the materials and ultimately leads to different tensile plasticity. This work is aimed at providing guidelines for the design of metallic glass matrix composites with complex second phase dendritic structures.

Development and Fabrication of Biocompatible Ti-Based Bulk Metallic Glass Matrix Composites for Additive Manufacturing.

Ti-based metallic glasses have a high potential for implant applications. The feasibility of a new biocompatible Ti-based bulk metallic glass composite for selective laser melting (SLM) had been examined. Therefore, it is necessary to design a high-glass-forming-ability Ti-based metallic glass (∆Tx = 81 K, γ = 0.427, γm = 0.763), to fabricate a partial glass-formable spherical powder (the volume fraction of the amorphous phase in the atomized Ti-based powders being 73% [size < 25 μm], 61% [25-37 μm], and 50% [37-44 μm]), and establish an SLM parameter (a scan rate of 600 mm/s, a power of 120 W, and an overlap of 10%). The Ti42Zr35Si5Co12.5Sn2.5Ta3 bulk metallic glass composite was successfully fabricated through SLM. This study demonstrates that the TiZrSiCoSnTa system constitutes a promising basis for the additive manufacturing process in terms of preparing biocompatible metallic glass composites into complicated graded foam shapes.

Gradient network architecture design induced strain delocalization and delayed failure in metallic glass matrix composites

Making composites with crystalline inclusions can improve plasticity in brittle metallic glasses. In this study, we show a new metallic glass matrix composite designed with a gradient network architecture made of amorphous matrix regions and gradient crystalline network regions. Using molecular dynamics simulations, we validated theoretically the hypothesized concept of this new composite. Our results show that the unique microstructure leads to significant strain delocalization which can delay the generation of catastrophic shear bands. This is resulted from the new mechanism by both forming diffuse embryonic shear bands in the thin crystalline network interface and hindering or guiding their formation and movement in thick crystalline network regions with the presence of internal stresses generated from the gradient. This work demonstrates the synergistic effects induced by the heterogeneous gradient network design in the mechanical properties of metallic glass matrix composites and may open up exciting new possibilities.

Synthesis and mechanical behavior of in-situ porous Ti particle reinforced Mg-Cu-Gd-Ag bulk metallic glass matrix composite

The in-situ porous Ti particle reinforced Mg-based bulk metallic glass matrix composites have been successfully prepared via dealloying reaction in metallic melt. The microstructure, thermal properties and mechanical properties of the composites containing various volume fraction of porous Ti particles were investigated in detail. It is shown that with higher content of porous Ti particles, the glass-forming ability of the composites degrades gradually with the precipitation of fine crystalline phases among the glassy matrix. When the volume fraction of porous Ti particle is 26.3 vol%, the composite shows an fracture strength of 1125 MPa, 14.1 % higher than the monolithic glassy base alloy. Furthermore, the composite also exhibit an improved plastic strain of 0.94 %. The in-situ porous Ti particle and the submicron crystalline phase can hinder the rapid propagation of the main shear bands, causing the generation of multiple shear bands. It is found that abundant shear bands are formed around the porous Ti particle. The present synthesis strategy of in-situ porous reinforcing phase will contribute to the breakthrough in designing novel metal matrix composites.

Design Optimization and Mechanical Properties of SiC Particle Reinforced Ti-Based Metallic Glass Matrix Composite.

Ti-based bulk metallic glass (BMG) alloys have attracted widespread attention due to their strong glass forming ability, high specific strength, and good corrosion resistance. However, the poor plasticity of BMGs limits their further application in the aerospace and aircraft fields, as well as others. We optimized the composition of SiC-reinforced, Ti-based metallic glass matrix composites (MGMCs) through finite element modeling (FEM). FEM of MGMCs containing irregularly shaped SiC particles with different contents was conducted. Stress and strain analyses were conducted to evaluate the effect of the particle volume fraction on the mechanical behavior of MGMCs, and an optimization value of 30% was obtained, which is conducive to plasticity improvement. Arc melting copper mold injection casting was used to verify the optimized SiC content. The results show that the electroless nickel plating treatment effectively improves the wettability between SiC particles and the amorphous matrix, enabling the successful preparation of SiC/MGMC with a volume fraction of 29.5% through traditional injection casting. The volume fraction of SiC plays a crucial role in the transition of fracture mode from splitting to shear in MGMCs. After adding lightweight SiC particles, the yield strength, plasticity, modulus, and specific strength were improved by 25%, 1471%, 46%, and 33%, indicating that the use of nickel-plated SiC particles in MGMCs is an effective strengthening and toughening method for BMGs.

Development of high-entropy metallic glass matrix composites with enhanced compressive mechanical properties at elevated temperatures

Metallic glass matrix composites (MGMCs) have received intensive attention due to their higher strength at room temperature compared with traditional metallic glasses. However, they suffer from lose of strength and microstructural instability at elevated temperatures due to softening and crystallization of the glass matrix. Here, a novel Ti-Zr-Hf-Nb-Ta-Cu-Be high-entropy MGMCs with improved high-temperature mechanical properties was developed through the multi-principle element alloying strategy of refractory elements, which effectively retards the degradation of high-temperature mechanical properties compared with traditional MGMCs. The results provide an effective route to design high-performance high-entropy MGMCs for the potential application in a wide temperature range.

Fast Degradation of Azo Dyes by In Situ Mg-Zn-Ca-Sr Metallic Glass Matrix Composite

Mg-based metallic glass (MG) has attracted extensive attention in the field of wastewater treatment due to its high decolorization rate in degrading azo dyes. However, the azo dye degradation rate of Mg-based MGs is strongly dependent on the particle size. Improving the intrinsic degradation efficiency using large particles is of great interest for future applications. In this work, in-situ metallic glass matrix composites (MGMCs) with high Mg content were successfully prepared by melt spinning. It is found that when the Mg content is 79-82%, the as-spun sample shows typical glassy characteristics. The SEM and XRD tests confirm that the as-spun sample is composed of α-Mg dendrite, multiple Mg-Zn intermetallic particles and an MG matrix. The degradation experiment using Direct Blue 6 and a 500 μm particle sample demonstrate that the Mg82Zn14Ca3Sr1 MGMC sample degrades azo dyes faster than typical Mg-Zn-Ca MG alloy. It can be attributed to the galvanic cell effect on the α-Mg/MG interface, which reduces the waste of active Mg atoms in the MG matrix according to the corrosion protection mechanism by the α-Mg anode sacrifice. This result provides a new perspective and insight into the design of azo dye degradation alloys and the understanding of degradation mechanisms.

Martensite transformation govern serration deformation of a metastable metallic glass matrix composite

A metastable Ti-based metallic glass matrix composite (MGMC) exhibits deformation behavior that is closely related to the temperature and strain rate in the supercooled liquid region. The state of the amorphous matrix varies with the temperature, resulting in different responses to the overall mechanical properties. The remarkable strain rate sensitivity makes the strength of this MGMC reach 1,355 MPa, which is more than that of most MGMCs at diverse strain rates. In addition, serration deformation induced by martensite transformation is found in MGMC, which is different from serrated flow caused by the movement of shear bands in metallic glasses. The serration behavior changes synchronously with the martensite transformation.

Development of Bulk Metallic Glass Matrix Composites (MGMC) by Inoculation and Their Laser Additive Manufacturing 2

Development of Bulk Metallic Glass Matrix Composites (MGMC) by Inoculation and Their Laser Additive Manufacturing 2

Modeling and Simulation of Microstructural Evolution in Zr based Metallic Glass Matrix Composites (MGMC) in Additive Manufacturing - Ceramics Proposal

Modeling and Simulation of Microstructural Evolution in Zr based Metallic Glass Matrix Composites (MGMC) in Additive Manufacturing - Ceramics Proposal

Development of Bulk Metallic Glass Matrix Composites (MGMC) by Inoculation and Their Laser Additive Manufacturing 4

Development of Bulk Metallic Glass Matrix Composites (MGMC) by Inoculation and Their Laser Additive Manufacturing 4

Microstructural Evolution in Laser Additive Manufacturing - Modeling and Simulation for Zr based Metallic Glass Matrix Composites (MGMC)

Microstructural Evolution in Laser Additive Manufacturing - Modeling and Simulation for Zr based Metallic Glass Matrix Composites (MGMC)

Development of Bulk Metallic Glass Matrix Composites (MGMC) by Inoculation and Their Laser Additive Manufacturing

Development of Bulk Metallic Glass Matrix Composites (MGMC) by Inoculation and Their Laser Additive Manufacturing

Development of Bulk Metallic Glass Matrix Composites (MGMC) by Inoculation and Their Laser Additive Manufacturing 3

Development of Bulk Metallic Glass Matrix Composites (MGMC) by Inoculation and Their Laser Additive Manufacturing 3

Modeling and Simulation of Microstructural Rvolution in Zr based Metallic Glass Matrix Composites (MGMC) in Additive Manufacturing - Proposal

Modeling and Simulation of Microstructural Rvolution in Zr based Metallic Glass Matrix Composites (MGMC) in Additive Manufacturing - Proposal

Modelling and Simulation of Microstructural Evolution in Zr Based Bulk Metallic Glass Matrix Composites (Bmgmc) in Additive Manufacturing – a Proposal, Opinion and Prospect

Modelling and Simulation of Microstructural Evolution in Zr Based Bulk Metallic Glass Matrix Composites (Bmgmc) in Additive Manufacturing – a Proposal, Opinion and Prospect

Microstructural Evolution in Zr based Bulk Metallic Glass Matrix Composites (BMGMC) in Additive Manufacturing - Modeling and Simulation

Microstructural Evolution in Zr based Bulk Metallic Glass Matrix Composites (BMGMC) in Additive Manufacturing - Modeling and Simulation

Orientation Relationships in Inoculated and Non Inoculated Zr Based Bulk Metallic Glass Matrix Composites for Laser Additive Manufacturing

Orientation Relationships in Inoculated and Non Inoculated Zr Based Bulk Metallic Glass Matrix Composites for Laser Additive Manufacturing