Design Of Bulk Metallic Glasses Research Articles

A generative deep learning framework for inverse design of compositionally complex bulk metallic glasses

The design of bulk metallic glasses (BMGs) via machine learning (ML) has been a topic of active research recently. However, the prior ML models were mostly built upon supervised learning algorithms with human inputs to navigate the high dimensional compositional space, which becomes inefficient with the increasing compositional complexity in BMGs. Here, we develop a generative deep-learning framework to directly generate compositionally complex BMGs, such as high entropy BMGs. Our framework is built on the unsupervised Generative Adversarial Network (GAN) algorithm for data generation and the supervised Boosted Trees algorithm for data evaluation. We studied systematically the confounding effect of various data descriptors and the literature data on the effectiveness of our framework both numerically and experimentally. Most importantly, we demonstrate that our generative deep learning framework is capable of producing composition-property mappings, therefore paving the way for the inverse design of BMGs.

A two-step fused machine learning approach for the prediction of glass-forming ability of metallic glasses

Metallic glasses (MGs) are often perceived as quintessential structural materials. However, the widespread application of MGs is hindered primarily by their limited glass-forming ability (GFA) for the manufacture of large-scale MGs. In this work, a two-step fused machine learning (ML) approach is proposed, aiming to provide an efficient tactic for the precise prediction of MGs with robust GFA. In our ML framework, alloy compositions are the only required inputs. Moreover, the dataset comprises alloys that can and cannot be cast into MGs. This departs from the conventional ML approach utilizing only a correct set of training data (i.e. alloys that can cast into MGs). The fusion algorithm is also employed to further improve the performance of ML approach. The critical casting sizes predicted by our ML model are in good agreement with those reported in experiments. This work has extensive implications for the design of bulk MGs with superior GFA.

Fast surface dynamics enabled cold joining of metallic glasses.

Design of bulk metallic glasses (BMGs) with excellent properties has been a long-sought goal in materials science and engineering. The grand challenge has been scaling up the size and improving the properties of metallic glasses of technological importance. In this work, we demonstrate a facile, flexible route to synthesize BMGs and metallic glass-glass composites out of metallic-glass ribbons. By fully activating atomic-scale stress relaxation within an ultrathin surface layer under ultrasonic vibrations, we accelerate the formation of atomic bonding between ribbons at a temperature far below the glass transition point. In principle, our approach overcomes the size and compositional limitations facing traditional methods, leading to the rapid bonding of metallic glasses of distinct physical properties without causing crystallization. The outcome of our current research opens up a window not only to synthesize BMGs of extended compositions, but also toward the discovery of multifunctional glass-glass composites, which have never been reported before.

Evolutionary intelligence in design and synthesis of bulk metallic glasses by mechanical alloying

ABSTRACTThe present work demonstrates a new approach of a combinatorial design of Bulk Metallic Glasses using evolutionary intelligence of genetic programming (GP) and genetic algorithm (GA). A glass-forming potential expression, carrying similar sense as the glass-forming ability (GFA) indicator expression, has been identified by principal component analysis and GP, enabling one to map the fitness of the composition from the multidimensional attribute space of the alloy in the course of GA search. The genetically inspired alloy compositions are evolved by GA search and subsequently validated through existing empirical knowledge. Two randomly chosen compositions are subjected to experimental trial where the glass-forming potential has been evaluated by amorphization potential through mechanical alloying. A literature-reported good glass -forming composition has been studied as a reference alloy and comparison was made for the proposed designed alloys.

Design of Bulk Metallic Glasses and Glass Matrix Composites Near Intermetallic Composition by the Principle of Competitive Growth

Design of Bulk Metallic Glasses and Glass Matrix Composites Near Intermetallic Composition by the Principle of Competitive Growth

Glass formability of W-based alloys through thermodynamic modeling: W–Fe–Hf–Pd–Ta and W–Fe–Si–C

Computational thermodynamics, based on the CALculation of PHAse Diagram (CALPHAD) method, can be an efficient way to predict phase stabilities in multi-component engineering materials. By calculating the stability of the liquid phase at low temperatures, this method could be a useful and cost-effective tool for the design of bulk metallic glasses. Based on the thermodynamic modeling of the constituent binary and ternary systems of W with Fe, Hf, Pd, Ta, Si, or C, thermodynamic databases are built to search for W-based metallic glasses in these alloying systems. Modeling of intermetallic phases combines input from first-principles total energy calculations and predictions of finite temperature properties from the Debye–Grüneisen model. Several plausible W-rich glass-forming alloys are identified in the W–Fe–Si–C quaternary system.

First-principles prediction and experimental verification of glass-forming ability in Zr-Cu binary metallic glasses

In the field of metallic materials with amorphous structures, it is vitally important to understand the glass formation and to predict glass-forming ability (GFA) in terms of constituent elements and alloy compositions. In this study, an expression has been formulated from first-principles calculations to predict the trend of GFA by hybridizing both internal energies and atomic-scale defect structures. The prediction of GFA from compositions has been verified successfully by available experimental data in the model Zr-Cu alloy system. The physical scenario revealed here has extensive implications for the design of bulk metallic glasses with superior GFA.

Compositional features of bulk metallic glasses analyzed with a tetrahedral composition diagram from s-, p-, d- and f-blocks

Abstract The compositional features of bulk metallic glasses were statistically analyzed with an s–dEf–dLpM–pMLD tetrahedral composition diagram comprising s-, p-, d- and f-blocks in the periodic table, early- and late-transition metals and Metal–Metalloid. The s–dEf–dLpM–pMLD diagram was filled with 25 BMGs with critical diameter over half-inch (∼12.7 cm), 264 BMGs with the critical diameter ranging 0.2–12 mm, 6150 amorphous alloys from 351 ternary systems and 35400 compounds. The analysis revealed that BMGs as well as the ternary amorphous alloys are principally plotted on s–dEf–dLpM and dEf–dLpM–pMLD faces and their edges and vertices, whereas no plots are seen in s–pMLD edge and deep inside the diagram of each component of s, dEf, dLpM or pMLD ≥10 at.%. The s–dEf–dLpM–pMLD tetrahedral composition diagram is a useful tool for alloy design of bulk metallic glasses.

Cu-based bulk metallic glasses designed by stability evaluations of liquid and amorphous phases

From the point of translation from liquid to amorphous phase, a new approach for composition design of bulk metallic glasses (BMGs) was suggested based on the stability estimations of liquid and amorphous phases. Gibbs free energy (Δ G) of liquid phase, which can be calculated approximately using mixing enthalpy (Δ H mix) and configuration entropy ( S config), was taken as a stability criterion of liquid phase. On the other hand, vacancy formation energy (Δ H h) was used to evaluate the stability of amorphous phase due to the linear relationship between Δ H h and crystallization temperature ( T x). Based on these two sides, new Cu-Zr-Nd bulk metallic glasses were designed and synthesized successfully by suction-casting into copper mold. Experimental results about glass-forming ability are consistent with the computational values, which not only proves the validity of the new approach for composition design but also shows the new BMG of Cu 60.5Zr 34Nd 5.5 can be cast into amorphous alloys with 2 mm in diameter.

Ti alloy design strategy for biomedical applications

Based on the empirical rules for the composition design of bulk metallic glasses, a general composition formula for forming nano/ultrafine-structure is suggested. According to this formula a group of quinary Ti alloys have been developed. By controlling the solidification conditions an in situ formed bimodal microstructure consisting of micrometer-sized dendritic β-Ti solid solution dispersed in a nano/ultrafine-structured matrix has been obtained in these quinary Ti alloys. The β-Ti solid solution contributes to the ductility and the low Young's modulus, while the nano/ultrafine-structured matrix contributes to the high strength. The combination of high strength and low Young's modulus offers potential advantages in biomedical applications.

Design of Bulk metallic glasses with high glass forming ability and enhancement of plasticity in metallic glass matrix composites: A review

To overcome some of the limits of existing metallic alloys, a new alloy design concept has been introduced recently in order to control the crystallinity, i.e. to utilize crystalline, quasicrystalline, and amorphous structures. In particular, bulk metallic glasses (BMGs) receive great attention because of their unique properties due to their different atomic configuration. Recently, significant progress in enhancing glass forming ability (GFA) has led to the fabrication of BMGs having potential for application as structural and functional materials. Moreover, successful design of BMG matrix composite microstructure suggests that the plasticity of BMGs can be controlled properly. In this review article, we introduce recent research results on the design of BMGs with high GFA and on the enhancement of plasticity in metallic glass matrix composites.