Enhancing rheology and mechanical properties of DLP 3D-printed Si_(3)N_(4)materials via composition optimization and gas-pressure sintering  

作　　者：Qing Qin Gang Xiong Lin Han Yujuan Zhang Zhen Shen Changchun Ge 

机构地区：[1]Institute of Powder Metallurgy and Advanced Ceramics,School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China [2]State Key Laboratory of Multimodal Artificial Intelligence Systems,Beijing Engineering Research Center of Intelligent Systems and Technology,Institute of Automation,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《International Journal of Minerals,Metallurgy and Materials》2025年第5期1220-1233,共14页矿物冶金与材料学报(英文版)

基　　金：supported in part by the National Natural Science Foundation of China.(Nos.62461160259,92360307 and 92267103).

摘　　要：Digital light processing(DLP)is a crucial additive manufacturing(AM)technique for producing high-precision ceramic com-ponents.This study aims to optimize the formulation of Si_(3)N_(4)slurry to enhance both its performance and manufacturability in the DLP process,and investigate key factors such as particle size distribution,photopolymer resin monomer ratios,and dispersant types to im-prove the slurry’s rheological properties.Through these optimizations,a photosensitive Si_(3)N_(4)slurry with 50vol%solid content was de-veloped,exhibiting excellent stability,and low viscosity(2.48 Pa·s at a shear rate of 12.8 s^(-1)).The effects of gas-pressure sintering on the material’s phase composition,microstructure,and mechanical properties were further explored,revealing that this technique significantly increases the flexural strength of the green sample from(109±10.24)to(618±42.15)MPa.The sintered ceramics exhibited high hard-ness((16.59±0.05)GPa)and improved fracture toughness((4.45±0.03)MPa·m^(1/2)).Crack trajectory analysis revealed that crack deflec-tion,crack bridging,and the pull-out of rod-likeβ-Si_(3)N_(4)grains,are the main toughening mechanisms,which could effectively mitigate crack propagation.Among these mechanisms,crack deflection and bridging were particularly influential,significantly enhancing the frac-ture toughness of the Si_(3)N_(4)matrix.Overall,this research highlights how monomer formulation and gas-pressure sintering strengthen the performance of Si_(3)N_(4)slurry in the DLP three-dimensional printing technique.This work is expected to provide new insights for fabricat-ing complex Si_(3)N_(4)ceramic components with superior mechanical properties.

关 键 词：additive manufacturing Si_(3)N_(4)slurry low viscosity pressure sintering 

分 类 号：TQ174[化学工程—陶瓷工业]