共查询到20条相似文献,搜索用时 125 毫秒
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过共晶铝硅合金中铝硅共晶相取向关系 总被引:1,自引:0,他引:1
许多文献得出了亚共晶铝硅合金共晶相存在一定的晶体学取向关系,但是过共晶合金中铝硅相的取向关系并没有文献明确给出。本实验在借鉴亚共晶铝硅合金的共晶相取向关系:(220)Al∥(111)Si〔111〕Al∥〔011〕Si,研究了过共晶铝硅合金的共晶相取向关系。通过标定过共晶铝硅合金两相区衍射斑点指数,确定了过共晶相的取向关系。结果表明过共晶铝硅合金共晶相具有与亚共晶铝硅合金共晶相相同的晶体学取向关系。 相似文献
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铁对铝硅合金性能的影响及抵消其有害作用的措施 总被引:12,自引:2,他引:10
铝硅合金因其具有优良的性能而得到了广泛地应用,铁相是铝硅合金中最为常见的杂质。综述了铁相对铝硅合金不同性能的影响;归纳了抵消和减轻铁相有害作用的措施。 相似文献
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CX型长效无公害铝硅合金变质剂的应用 总被引:6,自引:3,他引:3
本文介绍了CX型长效无公害铝硅合金变质剂对ZL108和ZL104合金的变质效果。结果表明:该变质剂对铝硅合金有双重变质作用,可同时细化和改善初生硅和共晶硅形貌,且具有速效和持效作用,提高铝硅合金的力学性能和铸件的使用性能;该变质剂加入量少,变质工艺简便,处理时无烟雾、粉尘和刺激性气味,具有良好的技术经济效果。 相似文献
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过共晶铝硅合金细化变质剂的研究 总被引:31,自引:6,他引:25
研究了一种过共晶铝硅合金的复合细化变质剂,具有同时细化初晶硅和变质共晶硅的良好效果,变质处理的过共晶铝硅合金中的块状初晶硅最大尺寸和杆状共晶硅长度尺寸均小于100μm,其力学性能超过了目前国内外相同成分的过共晶铝硅合金。 相似文献
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氧化镧对铝硅合金变质的研究 总被引:1,自引:0,他引:1
本论文通过加入一定熔剂的氧化镧对铝硅共晶合金的变质处理试验,开发出以氧化镧为基的LYLM变质剂。此变质剂对铝硅合金变质不仅具有良好的变质作用而且拥有良好的抗衰退性和保温性能.当在铝硅共晶合金中加入最佳加入量0.5~1.0%人wtLYLM变质剂后,其抗拉强度和延伸率分别提高了58%和289%.并且保温6h.重熔13次时,合金仍具有相当的强.度和延伸率.本文通过LYLM变质剂反应模型的建立,揭示了氧行镧是通过络合反应过程对铝硅合金起变质作用的. 相似文献
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通过电导率测量、金相观察、扫描电镜分析和X射线衍射分析,研究了Si含量、Cu含量和热处理工艺对Al-Si系铸造合金晶格常数和电性能的影响规律。结果表明:Si和Cu元素的添加会减小合金的电导率;当Si含量超过固溶极限后,Si含量的变化对晶格畸变程度影响不大,合金的电导率受Si相的体积百分数控制;而Cu在固溶极限内时,随其含量的增加,晶格畸变程度增大,合金的电导率可根据铝基体晶格常数的偏离量来评估;经过450℃,5 h+250,2 h热处理工艺,晶格畸变程度明显降低,合金的电导率有明显提高,增幅最高可达32%。 相似文献
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通过正交试验和验证试验研究了不同的Si、Zr、Cr元素含量对Al-Si合金电导率与力学性能的影响.结果表明:当合金的成分为5%Si、0.35%Zr、0.35%Cr、1%Cu、0.5%Mg,经过T6处理后,电导率达到25.35 MS/m,抗拉强度达到361 MPa,伸长率达到2.83%,布氏硬度为109.34,均超越ZL101A.合金中的Si在改善合金力学性能的同时直接减少Al基体的有效导电截面,使合金的电导率下降;微量Zr可以在几乎不影响电导率的情况下提高合金力学性能;Cr元素对合金起到一定的强化作用.通过试验可将Al-Si合金的电导率提高5%~8%. 相似文献
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Microstructure and performance of Al-Si alloy with high Si content by high temperature diffusion treatment 总被引:1,自引:0,他引:1
Zi-yang XIU Guo-qin CHEN Xiao-feng WANG Gao-hui WU Yan-mei LIU Wen-shu YANG 《中国有色金属学会会刊》2010,20(11):2134-2138
The Al-Si alloy with high Si content was prepared by pressure infiltration.Microstructure observation shows that three-dimensional structure(3D-structure) is obtained from irregular sharp Si particles via high temperature diffusion treatment(HTDT).Flat Si-Al interfaces transform to smooth curves,and Si phases precipitate in Al and Si-Al interface.The bonding of Si-Al interface is improved by HTDT,which improves the mechanical performance of Al-Si alloy.The bending strength of 3D-Al-Si alloy increases by 6% compared with that of Al-Si alloy,but the elastic modulus changes a little.The coefficient of thermal expansion(CTE) of the 3D-Al-Si alloy is 7.7×10-6/°C from 20 °C to 100 °C,which decreases by 7% compared with that of Al-Si alloy.However,HTDT has little effect on the thermal conductivity of Al-Si alloy. 相似文献
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Heat transfer during quenching of chill-cast modified and unmodified A357 Al-Si alloy was examined using a computer-aided
cooling curve analysis. Water at 60 °C and a vegetable oil (palm oil) were used as quench media. The measured temperatures
inside cylindrical probes of the A357 alloy were used as inputs in an inverse heat-conduction model to estimate heat flux
transients at the probe/quenchant interface and the surface temperature of the probe in contact with the quench medium. It
was observed that modified alloy probes yielded higher cooling rates and heat flux transients. The investigation clearly showed
that the heat transfer during quenching depends on the casting history. The increase in the cooling rate and peak heat flux
was attributed to the increase in the thermal conductivity of the material on modification melt treatment owing to the change
in silicon morphology. Fine and fibrous silicon particles in modified A357 probes increase the conductance of the probe resulting
in higher heat transfer rates. This was confirmed by measuring the electrical conductivity of modified samples, which were
found to be higher than those of unmodified samples. The ultrasound velocity in the probes decreased on modification. 相似文献
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通过导电率、硬度测试方法研究了Al-Er-Cu合金在等时时效与等温时效过程中的性能变化规律,利用透射电镜(TEM)、能谱分析(EDS)观察了合金析出相的析出及生长规律。结果表明:随着时效温度升高,整体上同一合金的导电率与硬度峰值出现时间均提前;300 ℃时效时,Al-Er-0.22Cu合金已经析出大量纳米级弥散相,析出强化了合金强度,提高了导电率,时效2 h时达到导电率峰值60.15%IACS,10 h达到硬度峰值43.1 HV0.05,Al-Er-0.22Cu合金在拥有高导电率的同时保持了较好的硬度。 相似文献
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S. G. Jia X. M. Ning P. Liu M. S. Zheng G. S. Zhou 《Metals and Materials International》2009,15(4):555-558
Cu-Ag-Zr alloy is a newly developed copper alloy material which has an excellent combination of high mechanical strength and
high electrical conductivity. By means of vacuum induction melting, Cu-Ag-Zr alloy was produced. The effects of aging processes
on the microhardness and electrical conductivity characteristics of Cu-Ag-Zr alloy were studied. After aging at 450 °C for
4h, the alloy showed an excellent combination of microhardness and electrical conductivity: the microhardness and electrical
conductivity reach 126 HV and 84%IACS, respectively. The precipitates responsible for the age-hardening effect are the fine
and dispersed Cu5Zr, which has a face center cubic structure. Cu5Zr precipitates are fully coherent with the Cu matrix and give the Cu-Ag-Zr alloy higher microhardness and higher electrical
conductivity. 相似文献