天然鳞片石墨粉末的微热压成形工艺  

Micro hot-pressing forming process of natural flake graphite powder

作　　者：吴海华 钟磊 贺俊超 梅永健 叶喜葱 黄才华 WU Hai-hua;ZHONG Lei;HE Jun-chao;MEI Yong-jian;YE Xi-cong;HUANG Cai-hua(School of Mechanics and Power,China Three Gorges University,Yichang 443000,China)

机构地区：[1]三峡大学机械与动力学院,湖北宜昌443000

出　　处：《材料热处理学报》2022年第3期160-167,共8页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金(51575313);华中科技大学材料成形与模具技术国家重点试验室开放课题研究基金(P2020-003)。

摘　　要：天然鳞片石墨粉末压制成形由于气体不易排除以及摩擦沿程阻力等问题存在,导致石墨粉末难以压实以及密度不均等现象产生,为此提出天然鳞片石墨粉末微热压成形新方法,制备出密度与孔洞均匀的天然鳞片石墨件,且解决成形性问题。研究了成形密度、单元层厚度及热固性酚醛树脂加入量等对石墨件层间结合性能的影响,通过分析抗弯强度变化、观察层间结合面三维微观形貌、层间结合状态等揭示层间结合机理。结果表明:当成形密度过高或过低时,石墨件易出现分层现象,当成形密度控制在1.2~1.6 g/cm^(3)时(对应的粉层相对压缩率为70.83%~78.13%),单元层间结合良好;通过在一定范围内提高热固性酚醛树脂加入量或减小单元层厚度均可改善层间的结合质量。结合面的微观不平度、粘结剂分布状态及其溢出量是保证层间结合性的关键。Due to problems like difficult elimination of gas and friction resistance along the way in compact forming of natural flake graphite powder,it is hard to compact graphite powder,uniform the density and so on.Therefore,a new method of micro hot-pressing of natural flake graphite powder is proposed to prepare the natural flake graphite parts with uniform density and holes,and solve the forming issue.The influence of forming density,unit layer thickness and adding amount of thermosetting phenolic resin on interlayer bonding properties of graphite parts was studied.The interlayer bonding mechanism was revealed by analyzing the change of bending strength and observing the three-dimensional micro morphology of interlayer bonding surface and interlayer bonding state.The results show that when the forming density is too high or too low,the graphite parts are prone to delamination.When the forming density is controlled at 1.2-1.6 g/cm^(3)(corresponding to the relative compression ratio of powder layer at 70.83%-78.13%),the interlayer bonding is good.The interlayer bonding quality can be improved by either increasing the adding amount of thermosetting phenolic resin within certain limits or reducing the unit layer thickness.The microscopic unevenness of the bonding surface,the distribution of binder and its overflow are the key to ensure the bonding performance between unit layers.

关 键 词：天然鳞片石墨粉末 微热压成形 抗弯强度 层间结合状态 

分 类 号：TF124[冶金工程—粉末冶金]