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稀土元素Ce对纯铜导电性及力学性能的影响 总被引:12,自引:0,他引:12
在纯铜中加入稀土元素Ce,研究不同含量Ce及不同保温时间对纯铜的导电性、抗拉强度、硬度、耐磨性等的影响.研究发现在纯铜中加入Ce起到净化、去杂质的作用,改善纯铜的导电性;也可使晶粒细化,改善纯铜的抗拉强度及其它力学性能.且熔炼时加入稀土后的保温时间要适当.在试验的条件下保温时间以30 min为宜,稀土Ce的最佳加入量w为0.02%. 相似文献
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连铸纯铜杆废品存在严重偏心现象,中心有大量的气孔、缩松等缺陷,是导致纯铜杆硬度和强度不足、耐磨性差、导电性低的主要原因。通过将结晶器由单侧进水改为双侧进水,可解决偏心问题。将结晶器插入深度增加,可使气孔、缩松问题得到解决。 相似文献
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利用铝和氧化铜的铝热反应向纯铜表面渗铝和氧化铝.通过显微硬度实验、耐磨性实验来研究铝和氧化铝的渗入对纯铜表面显微硬度、耐磨性的影响.结果表明,向纯铜中渗铝和氧化铝可以提高纯铜表面的硬度及耐磨性.铝和氧化铁的反应能够促进铝和氧化铝渗入到纯铜中,提高渗层的质量,增加渗层的厚度,但氧化铁加入量过多时,却阻碍渗层的形成.实验表明,渗剂中含铝25%、氧化铁10%、氧化铝20%时获得的表面复合层质量最好. 相似文献
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研究了稀土Ce加入量对挤压态纯铜杆的电导率、硬度和疲劳性能的影响.结果表明,加入稀土元素Ce的挤压铜杆晶粒明显比未加稀土的细小,起到细化晶粒的作用;加入稀土Ce能提高纯铜的电导率和硬度,改善挤压纯铜杆的疲劳性能,稀土Ce加入量为0.04%时,挤压纯铜杆的综合性能最好. 相似文献
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为进一步改善铁基金属结合剂的性能,以Cu-Ce合金、铁、锡、铜等为原料,采用热压烧结法制备金属结合剂,研究Cu-Ce合金对结合剂性能的影响。结果表明:随Cu-Ce合金粉质量分数的增加,铁基金属结合剂的密度、抗冲击强度均逐渐增加,而抗弯强度和洛氏硬度则表现出先增大后减小的趋势。当Cu-Ce合金的质量分数为8%时,洛氏硬度(HRB)达到最大;Cu-Ce合金的质量分数为6%时,抗弯强度最大,为518.12 MPa。在铁基金属结合剂中添加Cu-Sn合金粉会降低其各项力学性能。 相似文献
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采用铸造、冷轧和T6热处理制备了SiO2气凝胶(SA)增强铝基复合材料。研究了SA含量对Al-4Cu-0.1Sn合金显微组织(铸态与冷轧T6态)与力学性能的影响。结果表明,SA能有效地加入到Al-4Cu-0.1Sn合金中,并以球状形式均匀的分布在晶粒内部。铸态下,随着SA含量的增加,合金的显微硬度呈上升趋势。当SA含量为0.02%时,合金平均硬度(HV)达到最高85,相对于未添加SA的合金提升了49%,但铸态下添加SA的合金拉伸性能略微下降;冷轧T6态下,当SA含量为0.02%时,合金硬度(HV)为138。随着SA增加,合金的屈服强度与抗拉强度先升高后降低,当SA含量为0.04%时,合金屈服强度达到320 MPa,抗拉强度达到401MPa,相比于未添加SA的合金提升了10.3%和10.7%。添加SA能够提高铸态Al-4Cu-0.1Sn合金硬度的机理是其细化了铸态合金的晶粒,并使晶界处第二相由粗大的骨骼状变成细小的非连续状。添加SA提高冷轧T6态强度的机理是细化了Al2Cu相并消除了Al7Cu2Fe相。 相似文献
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Sn对镁合金显微组织和力学性能的影响 总被引:79,自引:10,他引:69
研究了Sn对镁合金显微组织和力学性能的影响。研究结果表明,纯镁中加入Sn后能使纯镁铸锭中粗大的柱状晶转化为均匀的等轴晶,并有效地细化晶粒,同时在显微组织中形成具有立方C1结构的Mg2Sn颗粒相。由于Mg2Sn颗粒相显微硬度和熔点高,热稳定性好,因而对基体具有有效的弥散强化作用,提高了MgSn二元合金的室温及高温强度。在Mg9Al0.8Zn基合金中加入少量的Sn便能有效地提高合金的耐热性,而加入过多的Sn反而会导致合金高温强度下降。 相似文献
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S. H. Huang 《Journal of Materials Engineering and Performance》2018,27(7):3199-3205
Effects of 1.5 wt.% Ag addition and solid solution?+?artificial ageing at 160 °C on the microstructure and mechanical properties of a Mg-5Sn alloy have been studied. The results show that Ag addition has significantly hardened the solution-treated Mg-5Sn alloy. During the ageing process, the hardness increase rate and the strength and ductility of the Mg-5Sn alloy at each state are also improved by Ag addition. The improved strengthening behavior is primarily attributed to the refinement distribution of the Mg2Sn precipitates, the enhanced precipitation process, and the synergistic strengthening effect of Mg2Sn and a metastable plate DO19 phase formed at lower ageing temperature. For each solution-treated alloy, the strength and ductility are higher than the corresponding cast ones. Ageing further enhances the yield strength, and the ductility of the Mg-5Sn-1.5Ag alloy is also increased after ageing. The fracture surfaces of the both peak-aged alloys exhibit the characteristic of a mixture of quasi-cleavage and ductile fracture. 相似文献
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以Cu-15Ni-8Sn合金粉为原料制备了粉末冶金试样,研究其在不同的固溶温度、冷压变形、时效温度和时效时间条件下的硬度,着重研究了840℃×15 min固溶+40%冷压变形条件下时效温度和时间对硬度及剪切强度的影响规律,采用金相及扫描电镜分析了相应的微观组织。结果表明,影响Cu-15Ni-8Sn合金硬度的主次因素为:冷压变形量>时效时间>时效温度>固溶温度,较优的工艺参数为840℃×15 min固溶+40%冷压变形+400℃×4 h时效,可获得37.6~38.3 HRC的高硬度和570~628 MPa的抗剪切强度。 相似文献
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Jie Cui Tianjiao Luo Yingju Li Xiaohui Feng Qiuyan Huang Yuansheng Yang 《金属学报(英文版)》2021,34(9):1265-1276
In this paper, the infl uence of the Sn element on the melt viscosity, grain size, shrinkage, and tensile properties of the subrapidly solidified Mg-6Al-4Zn alloy was studied. The results showed that the melt viscosity of the Mg-6Al-4Zn alloy was greatly decreased because of the addition of Sn. As the content of Sn increased from 0 to 1.8 wt.%, the grain size of the alloy was refined, and the dendrite microstructure was changed to rose-shaped ones simultaneously. The decreased melt viscosity and refined microstructure were conductive to the feeding of melt, which contributed to the reduction in volume fraction of shrinkage. The volume fraction of shrinkage of the Mg-6Al-4Zn-1.2 Sn alloy was reduced by 30.8%, compared with that of the alloy without Sn addition. Tensile properties of the Mg-6Al-4Zn-x Sn alloys were increased firstly and then decreased with the augmented Sn content. The yield strength, ultimate tensile strength, and elongation of the alloy containing 1.2 wt.% Sn were 21.4%, 39.5%, and 259.0% higher than those of the alloy without Sn addition, respectively. The addition of Sn was considered to reduce the shrinkage of the sub-rapidly solidified Mg-6Al-4Zn magnesium alloy and thus improved its tensile properties. To identify the mechanism, the effect of Sn on the volume fraction of shrinkage was discussed from three aspects of melt viscosity, grain refinement, and volume fraction of eutectic phases. 相似文献
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LI Rong-de LI Run-xia YU Li HU Zhuang-qi . Shenyang University of Technology Shenyang China . Shenyang University Shenyang China . Institute of Metal Research Chinese Academy of Sciences Shenyang China 《材料热处理学报》2004,(5)
AMONG the commercial aluminum cast alloys,Al-Si-Cu-Mg alloy is extensively used mainly becauseof its good castability and excellent mechanicalproperties in the heat treated condition[1,2].It isaccepted that two precipitation sequences are mainlyresponsible for the precipitation hardening ofAl-Si-Cu-Mg alloy[2-4],namely:—GP zonesphase and-*GP zonesphase.Where GPs are the Cu/MgGuinier-Preston zones,P"/9"and/9'are themetastable p h a s e s,a r e equilibrium phaserespectively.It is well … 相似文献
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WANGYan-hui WANGMing-pu HONGBin 《材料热处理学报》2004,25(5):97-100
The microstructure, property and relation between them of Cu-15Ni-8Sn alloy are studied by means of TEM and the measurement of hardness, The results show that γ‘ metastable phase strengthens alloy because of its ordering structure.The ordering structure includes two types of DO22 and L12 ordering. Their strengthening for the alloy is much stronger than that of spinodal decomposition. 相似文献