ATI 718Plus(简称718Plus)合金作为一种新型镍基变形高温合金涡轮盘材料,由于在700℃以下具备优异的综合力学性能、良好的热加工和焊接等工艺性能以及适宜的成本,而受到国内外的广泛关注。本文综述了近几年国内718Plus合金的研究进展,...ATI 718Plus(简称718Plus)合金作为一种新型镍基变形高温合金涡轮盘材料,由于在700℃以下具备优异的综合力学性能、良好的热加工和焊接等工艺性能以及适宜的成本,而受到国内外的广泛关注。本文综述了近几年国内718Plus合金的研究进展,主要包括:(1)718Plus合金相组成及合金特点;(2)P对718Plus合金组织及性能的影响规律及机理;(3)Al对718Plus合金组织及性能的影响规律及机理;(4)析出相对718Plus合金性能的影响规律及机理。展开更多
The potency of Al3Zr and Al3Nb as grain refiners for Al alloys was investigated from a crystallographic point of view using the edge-to-edge matching （E2EM） model. The results show that both Al3Zr and Al3Nb have sma...The potency of Al3Zr and Al3Nb as grain refiners for Al alloys was investigated from a crystallographic point of view using the edge-to-edge matching （E2EM） model. The results show that both Al3Zr and Al3Nb have small values of interatomic spacing misfit and interplanar spacing mismatch with respect to Al. Furthermore, energetically favourable orientation relationships predicted by the model exist between Al and each of these two intermetallic phases. In the light of the edge-to-edge matching model predictions, it is suggested that both Al3Zr and Al3Nb are potent heterogeneous nucleation refiners for Al grains from the crystallographic point of view. The present crystallographic analysis provides a more reasonable explanation for the significant grain refinement obtained in the peritectic Al-Zr and Al-Nb alloys and also provides fresh insight into the understanding of the grain refinement mechanism of Al alloys.展开更多
The refinement potential of AI-3.5FeNb-I.5C master alloy on pure aluminium and AI-9.8Si-3.4Cu alloy has been investigated. Different amounts of AI-3.5FeNb-I.5C master alloy were added to estimate the optimal addition ...The refinement potential of AI-3.5FeNb-I.5C master alloy on pure aluminium and AI-9.8Si-3.4Cu alloy has been investigated. Different amounts of AI-3.5FeNb-I.5C master alloy were added to estimate the optimal addition level. It was found that the addition of AI-3.5FeNb-I.5C grain refiner can promote significantly the refinement of grains in the pure aluminium, particularly at 0.1wt.%, with the mean primary aluminium a-grain size reducing to 187＋3 IJm from about 1-3 mm. Similarly, the microstructural study of the AI-9.8Si-3.4Cu alloy die casting at different weight percentages （viz. 0.0wt.%, 0.1wt.% and 1.0wt.%） of AI-3.5FeNb-I.5C master alloy shows that the AI-3.5FeNb-I.5C master alloy as a grain refiner is also acceptable for AI-Si cast alloys when the silicon content is more than 4wt.%. As a result of inoculation with AI-3.5FeNb-1.5C master alloy, the average grain size of a-AI is reduced to 22＋3 #m from about 71＋3 IJm and grain refining efficiency is not characterized by any visible poisoning effect, which is the major limitation in the grain refinement of AI-Si cast alloys by applying AI-Ti-B ternary master alloys. Mechanical properties such as ultimate tensile strength and yield strength are significantly improved by 9.6% and 9.7%, respectively.展开更多
Small amount(0.5-0.8at.%) of niobium addition to the multicomponent alloys based on Fe3Al(Fe-28Al-5Cr-0.5Mo-0.05Zr-0.05B-0.1Ce) results in the microstructural refinement and the increase in the yield strength at tempe...Small amount(0.5-0.8at.%) of niobium addition to the multicomponent alloys based on Fe3Al(Fe-28Al-5Cr-0.5Mo-0.05Zr-0.05B-0.1Ce) results in the microstructural refinement and the increase in the yield strength at temperatures up to 600℃,but is not beneficial to room temperature ductility.Results of microanalysis indicate that the addition of niobium causes the formation of precipitates with complex compositions which strengthen both matrix and grain boundaries and enhance the creep resistance of the alloys.展开更多
Nb_(3)Al nanoparticles were directly synthesized by metallothermic reduction process in the molten salts with mNbCl_(5)-nAlCl_(3) powders as raw materials and sodium as reducing reagent. The effects of different feedi...Nb_(3)Al nanoparticles were directly synthesized by metallothermic reduction process in the molten salts with mNbCl_(5)-nAlCl_(3) powders as raw materials and sodium as reducing reagent. The effects of different feeding material orders, soaking time, Nb content in raw materials, and 3NbCl_(5)-AlCl_(3) content in molten salts on the obtained Nb_(3)Al powder were discussed. The as-prepared samples were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), and transmission electron microscopy(TEM). It is found that the only phase Nb_(3)Al nanoparticles are obtained by controlling the variation of the feeding material orders, soaking time, and Nb content in raw materials. And the morphologies of as-prepared nanoparticles change owning to different 3NbCl_(5)-AlCl_(3) contents in molten salts.展开更多
基金the Australian Research Council for funding supportthe support of China Scholarship Council
文摘The potency of Al3Zr and Al3Nb as grain refiners for Al alloys was investigated from a crystallographic point of view using the edge-to-edge matching （E2EM） model. The results show that both Al3Zr and Al3Nb have small values of interatomic spacing misfit and interplanar spacing mismatch with respect to Al. Furthermore, energetically favourable orientation relationships predicted by the model exist between Al and each of these two intermetallic phases. In the light of the edge-to-edge matching model predictions, it is suggested that both Al3Zr and Al3Nb are potent heterogeneous nucleation refiners for Al grains from the crystallographic point of view. The present crystallographic analysis provides a more reasonable explanation for the significant grain refinement obtained in the peritectic Al-Zr and Al-Nb alloys and also provides fresh insight into the understanding of the grain refinement mechanism of Al alloys.
基金financially supported by the National Institute of Technology(NIT),Manipur-India to carry out the industrial experimental research work
文摘The refinement potential of AI-3.5FeNb-I.5C master alloy on pure aluminium and AI-9.8Si-3.4Cu alloy has been investigated. Different amounts of AI-3.5FeNb-I.5C master alloy were added to estimate the optimal addition level. It was found that the addition of AI-3.5FeNb-I.5C grain refiner can promote significantly the refinement of grains in the pure aluminium, particularly at 0.1wt.%, with the mean primary aluminium a-grain size reducing to 187＋3 IJm from about 1-3 mm. Similarly, the microstructural study of the AI-9.8Si-3.4Cu alloy die casting at different weight percentages （viz. 0.0wt.%, 0.1wt.% and 1.0wt.%） of AI-3.5FeNb-I.5C master alloy shows that the AI-3.5FeNb-I.5C master alloy as a grain refiner is also acceptable for AI-Si cast alloys when the silicon content is more than 4wt.%. As a result of inoculation with AI-3.5FeNb-1.5C master alloy, the average grain size of a-AI is reduced to 22＋3 #m from about 71＋3 IJm and grain refining efficiency is not characterized by any visible poisoning effect, which is the major limitation in the grain refinement of AI-Si cast alloys by applying AI-Ti-B ternary master alloys. Mechanical properties such as ultimate tensile strength and yield strength are significantly improved by 9.6% and 9.7%, respectively.
文摘使用自主研发的快热快冷处理设备,对粉末装管Nb/Al前驱线进行快热快冷处理,然后再经过800℃10 h转变退火处理,得到具有Nb3Al超导相的超导短样.通过扫描电镜观察分析超导样品微观结构,发现所有样品均有Nb3Al相存在,但在靠近Ta管内层有少量的Nb2Al相,超导芯内有少量的Nb剩余.在制冷机冷却的环境下使用四引线法测试了样品的超导性能.结果表明,自场下在10.9 K温度时,没有铜稳定体的Nb3Al超导线最高临界电流密度是66.5 A/mm2,超导起始转变温度是15~18 K.
文摘Small amount(0.5-0.8at.%) of niobium addition to the multicomponent alloys based on Fe3Al(Fe-28Al-5Cr-0.5Mo-0.05Zr-0.05B-0.1Ce) results in the microstructural refinement and the increase in the yield strength at temperatures up to 600℃,but is not beneficial to room temperature ductility.Results of microanalysis indicate that the addition of niobium causes the formation of precipitates with complex compositions which strengthen both matrix and grain boundaries and enhance the creep resistance of the alloys.
基金the National Natural Science Foundation of China(Nos.50934001,21071014,51102015,and 51401004)the Fundamental Research Funds for the Central Universities(Nos.FRF-AS-11-002A,FRF-TP12-023A,and FRF-MP-09-006B)+2 种基金the National High Technology Research and Development Program of China(No.2012AA062302)the Program of the Co-Construction with Beijing Municipal Commission of Education of China(Nos.00012047 and 00012085)the Program for New Century Excellent Talents in University(No.NCET-11-0577)。
文摘Nb_(3)Al nanoparticles were directly synthesized by metallothermic reduction process in the molten salts with mNbCl_(5)-nAlCl_(3) powders as raw materials and sodium as reducing reagent. The effects of different feeding material orders, soaking time, Nb content in raw materials, and 3NbCl_(5)-AlCl_(3) content in molten salts on the obtained Nb_(3)Al powder were discussed. The as-prepared samples were characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM), and transmission electron microscopy(TEM). It is found that the only phase Nb_(3)Al nanoparticles are obtained by controlling the variation of the feeding material orders, soaking time, and Nb content in raw materials. And the morphologies of as-prepared nanoparticles change owning to different 3NbCl_(5)-AlCl_(3) contents in molten salts.
