Research Overview
Stay hungry, stay foolish.
— The Whole Earth Catalog
Haijian Yang, Haoyou Zhang, et al. MeltPoolPhysicsNet: A thermal-physics-guided machine-learning framework for melt-pool prediction.
TL;DR: MeltPoolPhysicsNet, a thermal-physics-guided machine-learning framework trained on single-track experiments across pure metals, integrates laser parameters and thermophysical descriptors,particularly normalized enthalpy, to estimate melt-pool width, depth, aspect ratio, and processing regime.
Le Zhou, Haijian Yang, et al. Controlling mechanical properties of laser powder bed fused AlSi10Mg through manipulation of laser scan rotation.
TL;DR: Controlling inter-layer laser scan rotation angles (α) in LPBF-fabricated AlSi10Mg alloy significantly enhances tensile performance, with α = 0° yielding a higher strength and improved ductility due to the alignment of melt pool boundaries with the loading direction.
Haijian Yang, Le Zhou, et al. Mechanical Property and Microstructure of Laser Powder Bed Fused Hypereutectic Al16Ce1Mg Alloy.
TL;DR: LPBF-processed hypereutectic Al16Ce1Mg alloy demonstrated exceptional printability, tensile strength, and creep resistance enabled by solid solution strengthening, dislocation hardening. Dynamic strain aging-induced PLC effects and Ce-depleted zone evolution governed its strain rate sensitivity and high-temperature deformation.
TL;DR: L-PBF processed eutectic Al10CeXZr alloys demonstrated excellent printability and enhanced mechanical properties, with Zr-induced grain refinement and precipitation strengthening achieved optimal performance, while statistical analysis identified fabrication method and heat treatment as the key factors governing ductility and strength.
Haijian Yang, Le Zhou, et al. Heat-Treatment-Driven Phase-Tailored Creep Strengthening of Laser Powder Bed Fused Ti-6Al-4V Alloy.
TL;DR: Wide-window compressive creep database was estalished for LPBF Ti-6Al-4V and linked HIP-based phase tailoring (HIP/HIP+aging/HIP+STA) and quantified α/β microstructural metrics to transition/threshold stresses, activation energy, and diffusion-assisted dislocation creep, establishing a mechanism-guided post-processing strategy to improve elevated-temperature creep resistance.
Haijian Yang, Le Zhou, et al. High Creep Resistance of Zirconium Modification of Laser Powder Bed Fused Eutectic Al-Ce Alloys.
TL;DR: A quantitative creep–microstructure strategy for LPBF Al-10Ce-xZr combines incremental-load creep tests, multiscale characterization, and mechanism-based modeling to decouple eutectic-network, grain-boundary transport, solute diffusivity, and precipitation thresholding, thereby providing design guidelines that balance grain size, phase architecture, diffusivity, and precipitate strengthening for improved elevated-temperature performance.
TL;DR: Modified with Ce and T6 heat treatment synergistically enhance the strength and fatigue resistance of A356 alloy through Al₁₁Ce₃ intermetallic formation and eutectic Si refinement, highlighting a tunable strength-ductility-fatigue balance in Ce-modified Al-Si cast alloys.
Song K, Haijian Yang, et al. Machine learning-assisted 3D printing of thermoelectric materials of ultrahigh performances at room temperature.
TL;DR: A machine learning-assisted extrusion 3D printing strategy was developed to optimize ink formulations and process parameters, enabling the fabrication of complex-shaped BiSbTe-based thermoelectric materials; thermoelectric performance was further enhanced and electrical conductivity increased through HIP treatment by reducing porosity.
Hui Zhang, Haijian Yang, et al. Photothermal conversion characteristics of gold nanoparticles under different filter conditions.
TL;DR: Synthesized gold-nanoparticles exhibited high photothermal conversion efficiency and elevated specific absorption rates (SAR) under VIS-IR illumination, revealing critical property-spectrum relationships for nanoparticle-based thermal management applications.
Simulations
Haijian Yang. Dislocation-mediated Plasticity and Discrete Dislocation Dynamics.(PDF)
TL;DR: Three-dimensional discrete dislocation dynamics (DDD) simulations using ParaDiS reveal the evolution of dislocation evolution under creep conditions, providing mechanistic insights into steady-state creep behavior and informing lifetime prediction models.
Haijian Yang. Macroscopic simulation and experimental measurement of melt pool temperature and stress distribution during selective laser melting of Ti-6Al-4V.(PDF)
TL;DR: Integrating experimentally validated Gaussian heat source modeling with temperature-dependent Ti6Al4V via 3D finite element framework quantitatively revealing the thermal-mechanical coupling behavior in selective laser melting (SLM).