工程科学学报，第40卷，第9期：1075-1082,2018年9月 Chinese Journal of Engineering,Vol.40,No.9:1075-1082,September 2018 DOI:10.13374/j.issn2095-9389.2018.09.008 http://journals.ustb.edu.cn 粉末冶金铝合金烧结致密化过程 邱婷婷”，吴茂2)区，杜智渊”，曲选辉2》 1)北京科技大学新材料技术研究院，北京1000832)现代交通金属材料与加工技术北京实验室，北京100083 3)先进粉末治金材料与技术北京市重点实验室，北京100083 ☒通信作者：E-mail:wumao@usth.cdu.cn 摘要以纯A1粉为主要原料，添加Cu单质粉末以及A-Mg、A-Si中间合金粉，利用粉末治金压制烧结方法制备出相对密 度98%以上的Al-Mg-Si-Cu系铝合金.研究表明，烧结致密化过程主要分为3个阶段：初始阶段（室温~460℃），坯体内首先 形成A-Mg合金液相，液相中的Mg原子分别扩散至A1或ASi粉末中，与AL,O,反应并破除氧化膜，形成A-Mg0等化合 物：同时，A-Cu发生互扩散，形成A山2Cu等金属间化合物.第二阶段(460~560℃)，A-Cu、A-Si液相快速填充颗粒缝隙或孔 洞，坯体相对密度显著提高：此阶段的致密化机制主要是毛细管力引起的颗粒重排，以及溶解析出导致的晶界平直化.第三阶 段(560~600℃)，随温度的升高，液相润湿性提高，晶粒快速长大，使得大尺寸孔洞填充，烧结体基本实现全致密，此阶段的致 密化主要由填隙机制控制.在铝合金晶界处发现了MgA2O,和MgA1CO氧化物的存在，推测A1粉表面氧化膜的破除机制与 合金成分有关.由于ACu液相在AI表面的润湿速率远高于AIN的生长速率，因为在本体系中未发现AN的存在 关键词粉末治金：固相扩散：液相烧结：氧化膜：氮化铝 分类号TF124 Sintering densification process of powder metallurgy aluminum alloy QIU Ting-ting,WU Mao,DU Zhi-yuan,QU Xuan-hui) 1)Institute of Advance Materials and Technology,University of Science and Technology Beijing,Beijing 100083,China 2)Beijing Laboratory of Metallic Materials and Processing for Modern Transportation,Beijing 100083,China 3)Beijing Key Laboratory for Advanced Powder Metallurgy and Particulate Materials,Beijing 100083,China Corresponding author,E-mail:wumao@ustb.edu.cn ABSTRACT In this study,an Al-Mg-Si-Cu alloy was prepared by conventional press-and-sinter powder metallurgy techniques using pure Al powder,Cu element powder,and binary Al-Mg and Al-Si powders to investigate the processes of atom diffusion and mi- crostructure evolution.The relative density of the sintering samples exceeded 98%.It is found that the sintering densification process can be approximately divided into three stages.In the first stage (from room temperature to 460 C),after the Al-Mg eutectic liquid phase formed at 450C,the Mg atoms in the liquid diffuses into Al and Al-Si particles and reacts with Al,O at the metal/oxide inter- face to form an Al-Mg-O compound.Meanwhile,the interdiffusion between Al and Cu leads to the formation of Al,Cu compounds.In the second stage (from 460 to 560C),the micro-channels or small holes between the grain boundaries are rapidly filled by Al-Cu and Al-Si eutectic liquids,which leads to a significant increase of density.In this stage,the densification mechanisms are particle rear- rangement controlled by the capillary driving force and contact flattening dominated by solution-reprecipitation.In the last stage (from 560 to 600C),the residual large holes are finally filled by the liquid because of the enhancement of wettability and grain growth with the increase of sintering temperature.In this stage,the densification mechanism is mainly pore-filling,resulting from the grain growth. The sample is fully dense through this stage.In addition,MgAl,O,and MgAlCuO compounds are found in the grain boundary region: 收稿日期：201804-11 基金项目：国家自然科学基金资助项目(51774036)：新金属材料国家重点实验室自主课题资助项目(2016Z-24)工程科学学报，第 40 卷，第 9 期: 1075--1082，2018 年 9 月 Chinese Journal of Engineering，Vol． 40，No． 9: 1075--1082，September 2018 DOI: 10． 13374 /j． issn2095--9389． 2018． 09． 008; http: / /journals． ustb． edu． cn 粉末冶金铝合金烧结致密化过程 邱婷婷1) ，吴 茂1，2，3) ，杜智渊1) ，曲选辉1，2，3) 1) 北京科技大学新材料技术研究院，北京 100083 2) 现代交通金属材料与加工技术北京实验室，北京 100083 3) 先进粉末冶金材料与技术北京市重点实验室，北京 100083 通信作者: E-mail: wumao@ ustb． edu． cn 摘 要 以纯 Al 粉为主要原料，添加 Cu 单质粉末以及 Al--Mg、Al--Si 中间合金粉，利用粉末冶金压制烧结方法制备出相对密 度 98% 以上的 Al--Mg--Si--Cu 系铝合金． 研究表明，烧结致密化过程主要分为 3 个阶段: 初始阶段( 室温 ～ 460 ℃ ) ，坯体内首先 形成 Al--Mg 合金液相，液相中的 Mg 原子分别扩散至 Al 或 Al--Si 粉末中，与 Al2O3反应并破除氧化膜，形成 Al--Mg--O 等化合 物; 同时，Al--Cu 发生互扩散，形成 Al2Cu 等金属间化合物． 第二阶段( 460 ～ 560 ℃ ) ，Al--Cu、Al--Si 液相快速填充颗粒缝隙或孔 洞，坯体相对密度显著提高; 此阶段的致密化机制主要是毛细管力引起的颗粒重排，以及溶解析出导致的晶界平直化． 第三阶 段( 560 ～ 600 ℃ ) ，随温度的升高，液相润湿性提高，晶粒快速长大，使得大尺寸孔洞填充，烧结体基本实现全致密，此阶段的致 密化主要由填隙机制控制． 在铝合金晶界处发现了 MgAl2O4和 MgAlCuO 氧化物的存在，推测 Al 粉表面氧化膜的破除机制与 合金成分有关． 由于 Al--Cu 液相在 Al 表面的润湿速率远高于 AlN 的生长速率，因为在本体系中未发现 AlN 的存在． 关键词 粉末冶金; 固相扩散; 液相烧结; 氧化膜; 氮化铝 分类号 TF124 收稿日期: 2018--04--11 基金项目: 国家自然科学基金资助项目( 51774036) ; 新金属材料国家重点实验室自主课题资助项目( 2016Z--24) Sintering densification process of powder metallurgy aluminum alloy QIU Ting-ting1) ，WU Mao1，2，3)  ，DU Zhi-yuan1) ，QU Xuan-hui1，2，3) 1) Institute of Advance Materials and Technology，University of Science and Technology Beijing，Beijing 100083，China 2) Beijing Laboratory of Metallic Materials and Processing for Modern Transportation，Beijing 100083，China 3) Beijing Key Laboratory for Advanced Powder Metallurgy and Particulate Materials，Beijing 100083，China Corresponding author，E-mail: wumao@ ustb． edu． cn ABSTＲACT In this study，an Al--Mg--Si--Cu alloy was prepared by conventional press-and-sinter powder metallurgy techniques using pure Al powder，Cu element powder，and binary Al--Mg and Al--Si powders to investigate the processes of atom diffusion and mi￾crostructure evolution． The relative density of the sintering samples exceeded 98% ． It is found that the sintering densification process can be approximately divided into three stages． In the first stage ( from room temperature to 460 ℃ ) ，after the Al--Mg eutectic liquid phase formed at 450 ℃，the Mg atoms in the liquid diffuses into Al and Al--Si particles and reacts with Al2O3 at the metal /oxide inter￾face to form an Al--Mg--O compound． Meanwhile，the interdiffusion between Al and Cu leads to the formation of Al2Cu compounds． In the second stage ( from 460 to 560 ℃ ) ，the micro-channels or small holes between the grain boundaries are rapidly filled by Al--Cu and Al--Si eutectic liquids，which leads to a significant increase of density． In this stage，the densification mechanisms are particle rear￾rangement controlled by the capillary driving force and contact flattening dominated by solution-reprecipitation． In the last stage ( from 560 to 600 ℃ ) ，the residual large holes are finally filled by the liquid because of the enhancement of wettability and grain growth with the increase of sintering temperature． In this stage，the densification mechanism is mainly pore-filling，resulting from the grain growth． The sample is fully dense through this stage． In addition，MgAl2O4 and MgAlCuO compounds are found in the grain boundary region;