碳纤维含量对SLS覆膜砂型真空差压铸造铝合金组织及性能影响

发布时间：2018-01-20 06:02

本文关键词： 选择性激光烧结(SLS) 碳纤维覆膜砂真空差压铸造 ZL205A　出处：《南昌航空大学》2015年硕士论文　论文类型：学位论文

【摘要】：选择性激光烧结(SLS)覆膜砂型技术与真空差压铸造相结合,可快速铸造无余量、复杂薄壁精密铸件。通过将碳纤维加入覆膜砂,改善SLS覆膜砂型强度和导热性,在航空航天及国防领域中成形复杂薄壁件有极大优势。研究碳纤维含量对SLS覆膜砂型真空差压铸造铝合金组织及性能影响,为SLS覆膜砂型真空差压铸造铝合金奠定理论和技术支撑。本文以ZL205A铝合金为研究对象,通过将不同含量的碳纤维加入覆膜砂型,采用真空差压铸造成形ZL205A合金,研究碳纤维含量对ZL205A合金组织致密度、微观组织、机械性能的影响规律。实验结果表明,碳纤维含量对SLS覆膜砂型真空差压铸造铝合金组织及性能影响显著,当碳纤维含量小于3wt%时,随着碳纤维含量的增加,ZL205A致密度变大,微观组织变细小,抗拉强度和延伸率上升;当碳纤维含量超过3wt%时,致密度下降,微观组织变粗大,抗拉强度和延伸率下降;当碳纤维含量相同时,壁厚越大,致密度越高,强度降低,晶粒尺寸逐渐增大,微观组织形貌基本相同,均为等轴晶;随着试样部位从近横浇道部位到顶部,致密度先减小后增大,呈V型变化趋势,且近浇道部位达到峰值,随着碳纤维含量的增加,V型变化逐渐显著;当碳纤维含量为3wt%、壁厚为3mm时,晶粒尺寸最小38μm,抗拉强度和延伸率达到峰值,分别为496.42MPa和延伸率为10.23%。通过将碳纤维加入SLS覆膜砂型,研究获得碳纤维含量对真空差压铸造ZL205A铝合金组织及性能的影响规律,为SLS覆膜砂铸型真空差压成形复杂薄壁件铝合金铸件提供一定的理论依据和实际应用价值。
[Abstract]:Selective laser sintering (SLS) film coated sand mold technology combined with vacuum differential pressure casting (DPC) can be used for rapid casting of complex thin wall precision castings without allowance. Carbon fiber is added into coated sand. Improve the strength and thermal conductivity of SLS coated sand mold. The influence of carbon fiber content on the microstructure and properties of SLS coated sand mold by vacuum differential pressure casting is studied. For SLS film coated sand mold vacuum differential pressure casting aluminum alloy theoretical and technical support. This paper takes ZL205A aluminum alloy as the research object, by adding different content of carbon fiber coated sand mold. The effect of carbon fiber content on the microstructure density, microstructure and mechanical properties of ZL205A alloy was studied by vacuum differential pressure casting. The experimental results showed that the effect of carbon fiber content on the microstructure, microstructure and mechanical properties of ZL205A alloy was studied. The effect of carbon fiber content on the microstructure and properties of SLS coated sand mold by vacuum differential pressure casting is significant. When the carbon fiber content is less than 3 wt%, the density of ZL205A increases with the increase of carbon fiber content. The microstructure became smaller and the tensile strength and elongation increased. When the carbon fiber content is more than 3wt%, the density decreases, the microstructure becomes thicker, and the tensile strength and elongation decrease. When the content of carbon fiber is the same, the larger the wall thickness, the higher the density, the lower the strength, the larger the grain size, and the more uniform the microstructure is. With the sample position from the near transprue to the top, the density decreases first and then increases, and the near runner reaches the peak value. With the increase of carbon fiber content, the V-type changes gradually. When the carbon fiber content is 3wt and the wall thickness is 3mm, the grain size is minimum 38 渭 m, and the tensile strength and elongation reach the peak value. The results were as follows: 496.42 MPA and 10.23 respectively. Carbon fiber was added into SLS coated sand mold. The effect of carbon fiber content on the microstructure and properties of vacuum differential pressure casting (VDPC) ZL205A aluminum alloy was studied. It provides certain theoretical basis and practical application value for aluminum alloy castings of complex thin-walled parts formed by vacuum differential pressure forming of SLS coated sand mold.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG292;TB33

【共引文献】