本文研究了压力铸造条件下Al Si Cu多元合金的显微组织 ,通过与重力铸造条件下的比较发现 :压力铸造不仅能明显细化Al Si Cu合金中的共晶组织和初生相 (初生α Al或初生硅 ) ,而且可以改善Al Si Cu多元合金中金属间化合物的形态和分布 ...本文研究了压力铸造条件下Al Si Cu多元合金的显微组织 ,通过与重力铸造条件下的比较发现 :压力铸造不仅能明显细化Al Si Cu合金中的共晶组织和初生相 (初生α Al或初生硅 ) ,而且可以改善Al Si Cu多元合金中金属间化合物的形态和分布 ,甚至改变析出相的构成。展开更多
Effect of ultrasonic melt treatment on the macrostructure of solidified high purity aluminum was studied experimentally using metallographic method and complementary numerical calculations of acoustic pressure and vel...Effect of ultrasonic melt treatment on the macrostructure of solidified high purity aluminum was studied experimentally using metallographic method and complementary numerical calculations of acoustic pressure and velocity distribution in the melt. The results reveal that the macrostructure is effectively refined within a cone-shaped zone ahead of the irradiating face. Inner crystals along with wall crystals multiply particularly within the effectively refined zone and they contribute equally to structure refining. Isothermal holding after ultrasonic melt treatment results in loss of nucleation potency for nearly a half of nuclei, indicating that ultrasound activated heterogeneous nucleation may be as equal important as homogeneous nucleation for ultrasonic induced structure refining.展开更多
研究结果表明 :微量的Mg和Si均能促进Al Ti C中间合金对工业纯铝和 60 63合金等铝合金的晶粒细化作用 ;在细化温度相同的条件下 ,与Si相比 ,Mg对Al Ti C中间合金细化效果具有更大的促进作用 ;微量的Mg可以抑制Al Ti C中间合金晶粒细化...研究结果表明 :微量的Mg和Si均能促进Al Ti C中间合金对工业纯铝和 60 63合金等铝合金的晶粒细化作用 ;在细化温度相同的条件下 ,与Si相比 ,Mg对Al Ti C中间合金细化效果具有更大的促进作用 ;微量的Mg可以抑制Al Ti C中间合金晶粒细化的“温度效应” ;铝熔体中同时存在微量的Mg和Si时Al Ti C中间合金的细化效果更好。初步探讨了这两种微量元素促进Al Ti C中间合金细化效果的机理。展开更多
In-situ TiB2 particles reinforced 2014 aluminum alloy composite was prepared using an exothermic reaction process with K2TiF6 and KBF4 salts. The effects of CeO2 additive on the microstructure and properties of in-sit...In-situ TiB2 particles reinforced 2014 aluminum alloy composite was prepared using an exothermic reaction process with K2TiF6 and KBF4 salts. The effects of CeO2 additive on the microstructure and properties of in-situ TiB2/2014 composite were investigated. The results showed that CeO2 at high temperature exhibits the same function as Ce. When 0.5% （mass fraction） CeO2 additive was added, the dispersion of TiB2 particles in the matrix is improved significantly, and particles have no obvious settlement. The dispersing mechanism of TiB2 particles in 2014 Al alloy matrix was explained. Compared with the composite without CeO2, the hardness, tensile strength, yield strength and elongation of the composite with CeO2 addition are greatly increased in as-cast condition.展开更多
基金financially supported by the National Key Research and Development Program of China(No.2020YFB0311201)the National Natural Science Foundation of China(No.51627802)。
基金Project(51174135)support by the National Natural Science Foundation of ChinaProject(2012CB619505)supported by the National Basic Research Program of ChinaProject(NCET-13-0370)supported by the Program for New Century Excellent Talents in University
文摘Effect of ultrasonic melt treatment on the macrostructure of solidified high purity aluminum was studied experimentally using metallographic method and complementary numerical calculations of acoustic pressure and velocity distribution in the melt. The results reveal that the macrostructure is effectively refined within a cone-shaped zone ahead of the irradiating face. Inner crystals along with wall crystals multiply particularly within the effectively refined zone and they contribute equally to structure refining. Isothermal holding after ultrasonic melt treatment results in loss of nucleation potency for nearly a half of nuclei, indicating that ultrasound activated heterogeneous nucleation may be as equal important as homogeneous nucleation for ultrasonic induced structure refining.
文摘研究结果表明 :微量的Mg和Si均能促进Al Ti C中间合金对工业纯铝和 60 63合金等铝合金的晶粒细化作用 ;在细化温度相同的条件下 ,与Si相比 ,Mg对Al Ti C中间合金细化效果具有更大的促进作用 ;微量的Mg可以抑制Al Ti C中间合金晶粒细化的“温度效应” ;铝熔体中同时存在微量的Mg和Si时Al Ti C中间合金的细化效果更好。初步探讨了这两种微量元素促进Al Ti C中间合金细化效果的机理。
基金Project (2008AA03A239) supported by the High-tech Research and Development Program of China
文摘In-situ TiB2 particles reinforced 2014 aluminum alloy composite was prepared using an exothermic reaction process with K2TiF6 and KBF4 salts. The effects of CeO2 additive on the microstructure and properties of in-situ TiB2/2014 composite were investigated. The results showed that CeO2 at high temperature exhibits the same function as Ce. When 0.5% （mass fraction） CeO2 additive was added, the dispersion of TiB2 particles in the matrix is improved significantly, and particles have no obvious settlement. The dispersing mechanism of TiB2 particles in 2014 Al alloy matrix was explained. Compared with the composite without CeO2, the hardness, tensile strength, yield strength and elongation of the composite with CeO2 addition are greatly increased in as-cast condition.
