冷热循环下铝基复合材料构件尺寸稳定性影响因素研究  

Effect of Thermal Cycling on Dimensional Stability of Aluminum Matrix Composite Component

作　　者：杨光 金延文 张峻凡 王东[3] YANG Guang;JIN Yanwen;ZHANG Junfan;WANG Dong(Beijing Remote Sensing Equipment Research Institute,Beijing 100854,China;Zhongke Composite(Binzhou)New Materials Co.,Ltd.,Shandong Binzhou 256600,China;Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)

机构地区：[1]北京遥感设备研究所,北京100854 [2]中科复材(滨州)新材料有限公司,山东滨州256600 [3]中国科学院金属研究所,沈阳110016

出　　处：《精密成形工程》2024年第4期87-94,共8页Journal of Netshape Forming Engineering

基　　金：国家重点研发计划(2022YFB3707400)。

摘　　要：目的研究高精度仪器结构件在冷热变化过程中的尺寸变化原理和关键影响因素。方法采用粉末冶金法制备25%(体积分数)SiC/2009Al复合材料锻件,并加工出典型零件。研究了退火工艺对材料组织和性能的影响规律以及−45~65℃的冷热循环过程对零件尺寸精度的影响,并采用代表性体积单元模型和有限元方法分析了复合材料微区应力演化行为及其对材料尺寸稳定性的影响。结果SiC颗粒与铝基体线膨胀系数的差异会导致复合材料在制备过程中产生大量热错配位错。退火过程会显著减少铝基体中的位错数量,有助于提升材料的尺寸稳定性,但对材料的力学性能没有明显的影响。在−45~65℃下冷热循环720次,零件典型平面的平面度没有明显变化。结论冷热循环过程会在一定程度上影响颗粒与基体之间的应力分配,多次循环后复合材料微区应力-应变没有明显改变,因此零件的平面度没有明显变化。The work aims to study the dimensional change principle and key influencing factors of high precision instrument structure in thermal cycling.In this study,25vol.%SiC/2009Al composite forgings were prepared using powder metallurgy,and the typical component was machined.The effect of annealing processes on the microstructure and properties of the composite was investigated.The effect of thermal cycling process(−45‒65℃)on the dimensional accuracy of the component was discussed.The micro-scale stress evolution behavior of the composite and its impact on dimensional stability was analyzed using representative volume unit models and finite element methods.The results indicated that the difference in thermal expansion coefficients between SiC particles and the aluminum matrix lead to the generation of a large amount of thermal mismatch dislocations during the preparation of the composite.The annealing process significantly reduced the number of dislocations in the aluminum matrix,contributing to improve the dimensional stability of the composite,but it had no significant impacts on the mechanical properties of the composite.After 720 cycles of thermal cycling from−45℃to 65℃,there was no significant change in the flatness of the typical plane of the component.Simulation results suggest that the thermal cycling process will affect the stress distribution between the particles and the matrix to a certain extent.However,after multiple cycles,there is no significant change in the micro-scale stress-strain of the composite,resulting in no significant change in the flatness of the component.

关 键 词：铝基复合材料 尺寸稳定性 仪器仪表结构件 有限元 代表性体积单元 

分 类 号：TG146.2[一般工业技术—材料科学与工程]