基于Voronoi图的WC基硬质合金微观结构建模及优化  

Microstructure Modeling and Optimization of WC-Based Cemented Carbide Based on Voronoi Diagram

作　　者：黄丽容[1] 罗开臣 谢俊杰 苏彬彬 宋小军[1] 黄必华 Huang Lirong;Luo Kaichen;Xie Junjie;Su Binbin;Song Xiaojun;Huang Bihu(School of Mechanical and Electronic Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,China;Chongyi Zhangyuan Tungsten Co.,Ltd.,Ganzhou 341300,China;School of Electrical Engineering and Automation,Jiangxi University of Science and Technology,Ganzhou 341000,China)

机构地区：[1]江西理工大学机电工程学院,江西赣州341000 [2]崇义章源钨业股份有限公司,江西赣州341300 [3]江西理工大学电气工程与自动化学院,江西赣州341000

出　　处：《稀有金属》2023年第10期1369-1379,共11页Chinese Journal of Rare Metals

基　　金：江西省自然科学基金项目(20171BAB206030);赣州市重点研发计划工业领域、创新领军人才计划项目(赣市科发[2020]60号)资助。

摘　　要：微观结构是影响硬质合金硬度、断裂韧性等性能的重要因素。鉴于Voronoi图可以表征晶粒形态且具有良好的可控性,提出一种基于Voronoi图的WC基两相硬质合金微观结构建模方法。引入扰动法建立赋有WC平均晶粒尺寸特征的初始Voronoi图;考虑硬质合金存在部分晶粒尺寸差异大、尺寸跨度大的情形,提出基于修改Voronoi种子点局部分布密度以控制晶粒尺寸的单元抽取法和选择投放法,结合二者建立晶粒尺寸分布调控模型;针对模型中粘结相体积分数和邻接度的误差不可控问题,建立关于两个参数的多目标优化函数,采用多目标遗传算法(NSGA-Ⅱ)进行优化。结合案例分析,结果表明:模型的WC晶粒尺寸分布误差总体控制在6%以下,未优化的各参数误差大于5%,NSGA-Ⅱ优化后,WC平均晶粒尺寸误差小于3%,粘结相体积分数和邻接度的误差减小至2%以下,且模型表征了硬质合金真实微观结构的随机性,验证了建模方法的可行性,为硬质合金后续的力学性能预测和微观结构优化提供误差可控的基础模型。Cemented carbide is a composite material composed of hard phase with high hardness and high melting point, and metallicbinder phase with high toughness. WC-based cemented carbide is widely used because of its excellent properties. However, microstructure is an important factor affecting the hardness, fracture toughness and other properties of cemented carbide. Using computer simulation technology to accurately reappear the microstructure characteristics of cemented carbide is the basis of simulating their micromechanical behavior, which is an important means to explore the relationship between microstructure and mechanical properties, and microstructure optimization of cemented carbide. As a common microstructure modeling method of polycrystalline materials, Voronoi diagram can approximately represent the random microstructure, and has good controllability in characterizing the microstructure parameters. Therefore, aiming at the microstructure parameters of cemented carbide such as average grain size and size distribution, volume fraction of metallic binder phase and adjacency degree, and considering the randomness of real microstructure, a microstructure modeling method of WC-based two-phase cemented carbide based on Voronoi diagram was proposed. By introducing the perturbation method and adding the characteristic information of WC average grain size, the initial Voronoi diagram with WC average grain size characteristic was constructed through controlling the coordinates of seed points. Because the grain size of the initial Voronoi diagram was relatively uniform, it was not suitable for the case of largespanor uneven grain size distribution of WC. Therefore, it was necessary to further control the grain size distribution of the generated initial Voronoi diagram. Based on the initial Voronoi diagram, the element extraction method and selective placement method based on modifying the local distribution density of Voronoi seed points to control the grain size were proposed, and the effects of the two methods on the

关 键 词：WC硬质合金 微观结构 VORONOI图 晶粒尺寸分布 多目标优化 

分 类 号：TG146.41[一般工业技术—材料科学与工程] TP391.9[金属学及工艺—金属材料]