Jianbao Gao

Huazhong University of Science and Technology | hust

A novel crack-free Ti-modified Al-Cu-Mg alloy for SLM was developed here, based on the thermodynamic calculations of the crack susceptibility index and growth-restriction factor. We found that the introduction of Ti into the Al-Cu-Mg alloy effectively promoted the grain refinement and columnar-to-equiaxed grain transition as a result of the heterog...

In this paper, the in-situ Scanning Electron Microscopy (in-situ SEM) technique and three-dimensional (3-D) phase-field simulation were combined to perform a comprehensive study on the kinetics and mechanisms of dewetting (or agglomeration) of a 30 nm NiSi films on Si(100) substrate at 600°C. The evolution of texture during agglomeration of the pol...

High-throughput calculations/simulations are the prerequisite for the efficient design of high-performance materials. In this paper, a machine learning accelerated distributed task management system (Malac-Distmas) was developed to realize the high-throughput calculations (HTCs) and storage of various data. The machine learning was embedded in Mala...

Scandium is the best alloying element to improve the mechanical properties of industrial Al-Si-Mg casting alloys. Most literature reports devote to exploring/designing optimal Sc additions in different commercial Al-Si-Mg casting alloys with well-defined compositions. However, no attempt to optimize the contents of Si, Mg, and Sc has been made due...

In-depth understanding of nickel (Ni) coarsening is helpful for improving the service life of Ni-yttria stabilized zirconia (YSZ) electrodes in solid oxide cells. Unfortunately, very few quantitative experimental/theoretical descriptions of Ni coarsening in Ni-YSZ electrodes during long-term operation exist. In this paper, quantitative modeling of...

Lightweight refractory high-entropy alloys (LW-RHEAs) hold significant potential in the fields of aviation, aerospace, and nuclear energy due to their low density, high strength, high hardness, and corrosion resistance. However, the enormous composition space has severely hindered the development of novel LW-RHEAs with excellent comprehensive perfo...

In this paper, it was found for the first time that with Sr addition in Al–Si–Mg–Ce alloy, the morphology of eutectic (Si) can be modified from branch to fine fibrous, while the bulk-like Al2Si2Ce phase may replace the elongated needle-like one. Moreover, Mg was observed to segregate along the (Al)/Al2Si2Ce interface and Sr was found to concentrate...

Balancing the hardness and electrical conductivity of copper alloys within complex compositions and processes poses a formidable challenge. This study proposes a strategy combining machine learning with the Pareto front techniques to identify optimal combinations of composition and processing for Cu-xTi (1.5 ≤ x ≤ 5.4, in wt.%) alloys. Through ther...

It is difficult to fabricate dense and high-performance pure copper with most commercial medium-power fiber laser additive manufacturing machines due to its high laser reflection and thermal conductivity. The modification of the copper surface with high laser absorptance particles is an economical and effective way. However, the additions of high l...

Gradient nanostructured (GNS) metals exhibit superior mechanical properties compared with their counterparts containing a homogeneous microstructure. However, GNS materials usually suffer from the abnormal grain growth (AGG) when subjected to elevated temperatures, resulting in the instability of the gradient nanostructure and the degradation of me...

In this paper, thermodynamic descriptions of binary Si-Yb and ternary Al-Si-Yb system were assessed using the CALculation of PHAse Diagram (CALPHAD) technique, from which insights to the solidification behaviors of Yb-modified Al-Si alloys were attained. Firstly, all the experimental phase equilibria and thermodynamic properties in binary Si-Yb and...

In this study, insights into the effect of interfacial anisotropy on a complex hexagonal close-packed (hcp) dendritic growth during alloy solidification were gained by graphics processing unit (GPU)-accelerated three-dimensional (3D) phase-field simulations, as demonstrated for a Mg–Gd alloy. An anisotropic phasefield model with finite interface di...

Copper thin films are frequently utilized as microelectronic interconnects. Inducing abnormal grain growth (AGG) may result in reduced electrical resistivity of copper thin films. However, an in-depth understanding of AGG mechanism and quantitative simulation of microstructure evolution during AGG in copper thin films are still missing, prohibiting...

金属增材制造涉及传热与传质、相变、晶粒生长、熔体流动等多个复杂物理过程，实现其微结构演变的定量模拟难度大。相场法采用序参量可描述气/液/固相、晶粒形状/取向等复杂微结构，且能直接引入描述各物理过程的场变量（如浓度、温度、熔体流速等），在金属增材制造过程微结构模拟方面显示出巨大优势。本文简要介绍了相场法的发展和分类，归纳了不同相场模型的特点，详细综述了不同相场模型在金属增材制造凝固过程中微结构演化模拟的研究进展，重点探讨了不同相场模型在金属增材制造领域应用的优势与局限性。最后，展望了相场法在金属增材制造领域的应用前景，并指出其发展方向。 Metal additive manufacturing involves many complex physical processes such as h...

Achieving superior mechanical properties of Al alloys with high content of Fe impurities is very challenging. Here, a feasible method was applied to accommodate high Fe content (∼2.2 wt.%) and obtain superior strength in an Al–5Mg2Si–2Mg–2Fe alloy by using additive manufacturing. Heterogeneous distribution of Fe, including a high number density of...

Al-Si-Mg series alloys are the most common alloys available for additive manufacturing forming with low cracking tendency. However, there is no systematic study on the computational design of SLMed Al-Si-(Mg) alloys due to the huge parameter space of composition and processes. In this paper, a high-quality dataset of SLMed Al-Si-(Mg) alloys contain...

As the rapid development of computer technology, the computational thermodynamics in the framework of the CALculation of PHAse Diagram (CALPHAD) approach, the data-driven machine learning technique, and also their combinations have been proven to be the effective approaches for the design of casting aluminum alloys. The multicomponent Al-Si-Mg-Sr-T...

Achieving a homogeneous equiaxed grain structure and breaking the strength–ductility trade-offin ad- ditively manufactured aluminum alloys is a great challenge. In this paper, we propose a novel duplex nucleation mechanism that combines ex situ TiB 2 and in situ Al 3 Ti for controlling the grain structure of additively manufactured AlCuMgTi-TiB 2 c...

增材制造技术为高强铝合金复杂零部件的制造带来了前所未有的机遇， 但目前增材制造铝合金体系仍 局限于可铸造和可焊接的 Al-Si 系合金， 制约了高性能增材制造铝合金的快速发展。近年来， 不同尺度的计算 方法逐步用于辅助高性能增材制造铝合金的开发。本文详细综述了国内外学者在计算辅助增材制造铝合金 设计与制备领域的研究成果， 列举了原子、 介观和宏观尺度计算模拟及机器学习等计算方法辅助增材制造铝 合金设计的代表性案例， 分析了不同计算方法辅助合金设计的策略， 并指出其不足。最后， 针对如何推动多尺 度计算在高性能增材制造铝合金开发中的应用进行了展望， 并指出其发展方向。 Additive manufacturing technology has greatly increased opportu...

In this paper, an efficient design of a Ti-modified Al-Si-Mg-Sr casting alloy with simultaneously enhanced strength and ductility was achieved by integrating computational thermodynamics, machine learning, and key experiments within the Bayesian optimization framework. Firstly, a self-consistent Al-Si-Mg-Sr-Ti quinary thermodynamic database was est...

In this work, a novel computational model for the description of the temperature- and composition-dependent isotropic interfacial energy in multicomponent alloys was first developed in the framework of the CALculation of PHAse Diagram (CALPHAD) approach and implemented in a home-made code. By linking to the open-source code for interfacial energy c...

The effect of Co, Pd and Pt ultrathin films on the kinetics of the formation of Ni-silicide by reactive diffusion is investigated. 50 nm Ni/1 nm X/ 50 nm Ni (X = Co, Pd, Pt) deposited on Si(100) substrates are studied using in-situ and ex-situ measurements by X-ray diffraction (XRD). The presence of Co, Pd or Pt thin films in between the Ni layers...

Casting aluminum alloys are commonly used in industries due to their excellent comprehensive performance. Alloying/microalloying and post-solidification heat treatments are the most common measures to tune the microstructure for enhancing their mechanical properties. However, it is very challenging to achieve accurate and efficient development of n...

A356 alloys are widely used in industries due to their excellent comprehensive performance. Sr is usually added in A356 alloys to improve their mechanical properties. There have been various experimental reports on the optimal additional amount of Sr in A356 alloys, but their results are inevitably inconsistent. In this paper, a combination of comp...

In this paper, the effect of different casting means and heat treatment routines on the mechanical and corrosion resistance properties of A356-0.54Sc casting alloy was comprehensively studied. Three different molds, including graphite mold, steel mold, and copper mold, were employed. Both the grain size and secondary dendrite arm space of primary α...

All the experimental phase equilibria and thermodynamic properties in the Si–Sr and Al–Si–Sr systems were critically reviewed. Based on the reviewed experimental data, the thermodynamic descriptions of the Si–Sr binary system were updated by using the CALculation of PHAse Diagram (CALPHAD) technique, resulting in better agreement with the experimen...

In this paper, the effect of different cooling media, i.e., water quenching, air cooling and furnace cooling, after solid solution treatment on the microstructure and yield strength of Ni- 15.9Al at. pct alloy during aging at 800 �C was first experimentally investigated. It was found that the morphologies and the particle sizes of c¢ precipitates a...

The effect of different initial structures on the simulation of microstructure evolution during normal grain growth was comparatively studied by using a two-dimensional phase-field model. Three methods, standard Voronoi construction, weighted Voronoi construction, and hand drawing, were used to generate the initial structures. For the hand-drawn in...

In the present paper, three Co-Al-W-Ni alloys (i.e., Co-9Al-10W-xNi with x=15, 25, 35 at. %) and their heat treatment mechanisms were carefully designed on the basis of the available phase equilibrium information. The temporal evolution of the microstructure and hardness in the Co-9Al-10W-xNi (x=15, 25, 35) alloys during aging process was measured,...