机构地区:[1]西安理工大学材料科学与工程学院,西安710048 [2]西安建筑科技大学冶金工程学院,西安710055 [3]西北有色金属研究院,金属多孔材料国家重点实验室,西安710016
出 处:《材料导报》2021年第7期7114-7120,共7页Materials Reports
基 金:国家自然科学基金(51671152,51874225);陕西省教育厅服务地方专项计划项目;金属多孔材料国家重点实验室资助。
摘 要:金属点阵多孔材料是一种具有复杂周期性结构的先进轻质多功能材料,由于其优异的比强度、吸声、降噪以及超材料等特性,近年来备受关注。而传统的制备工艺仅可以制造类点阵结构,难以生产复杂、精细的点阵结构,成为金属点阵多孔材料进一步应用的掣肘。近年来快速发展的增材制造(Additive manufacturing,AM)技术具有设计与制造自由度大、快速制造任意复杂几何形状零件的特点,可对金属点阵多孔材料进行微观、界观和宏观尺度晶格的多种组合进行调控,是金属点阵多孔材料制备技术的前沿。然而,增材制造金属点阵多孔材料存在残余应力大、表面粗糙度高以及局部应力集中等问题,导致其压缩脆性以及疲劳强度较低。因此,除了研究增材制造工艺参数对点阵结构性能的影响外,研究者们主要从拓扑优化以及后处理方面不断进行尝试,并获得了丰硕的成果。结合拓扑优化设计,可使得应力分布更均匀,更好地服役于不同的加载环境;梯度点阵结构的压缩强度以及能量吸收是均匀点阵结构的两倍以上;通过热处理以及化学蚀刻可以降低点阵结构的残余应力和表面粗糙度,大幅提高其点阵结构的疲劳强度。通过控制单胞结构的分级孔隙度分布、合适的后处理,有望同时实现高孔隙率、高疲劳强度和高能量吸收。本文首先陈述了增材制造金属点阵多孔材料的优势和成形准则,随后介绍了单胞形状、单胞尺寸、支柱直径、体积孔隙率等因素对点阵结构尺寸精度和表面粗糙度的影响,并归纳了这些因素对点阵结构的屈服强度、能量吸收率和疲劳强度等性能的影响。此外,总结了点阵结构的拓扑优化和后处理对其性能的影响,最后介绍了增材制造金属点阵结构存在的掣肘,并展望了其未来的研究趋势。Metal lattice porous materials are advanced lightweight and multifunctional materials with complex periodic structure.Due to its excellent specific strength,sound absorption,noise reduction and metamaterials,they has attracted much attention in recent years.These characteristics make the metal lattice porous materials have a wide range of applications in the fields of medical implantation and aerospace.At the same time,the traditional preparation process can only manufacture lattice-like structures,and has many defects,making them difficult to produce complex and fine lattice structures,making the application of metal lattice porous materials encounter a bottleneck.In recent years,the rapid development of additive manufacturing(AM)technology has the characteristics of large design,manufacturing freedom and rapid manufacturing of any complex geometric parts.It is the forefront of metal lattice porous materials preparation technology to regulate and control multiple combinations of grids.However,the additive manufacturing of metal lattice porous materials have problems such as large residual stress,high surface roughness,and local stress concentration,which result in low compression brittleness and low fatigue strength.Therefore,in recent years,in addition to studying the effects of additive manufacturing process parameters on the performance of lattice structures,researchers have continued to try from the perspective of topology optimization and post-processing,and have achieved fruitful results.Combined with topology optimization design,it can make the stress distribution more uniform and better serve in different loading environments;the compressive strength and energy absorption of the gradient lattice structure are more than twice that of the uniform lattice structure;it can be reduced by heat treatment and chemical etching.The residual stress and surface roughness of the lattice structure greatly increase the fatigue strength of the lattice structure.By controlling the hierarchical porosity distribution of th
关 键 词:金属点阵多孔材料 增材制造 成形准则 能量吸收特性
分 类 号:TB3[一般工业技术—材料科学与工程]
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