共查询到19条相似文献,搜索用时 60 毫秒
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用机械合金化方法制备Ni—Al系金属间化合物 总被引:8,自引:1,他引:7
用球磨机分别对Ni-50at.-%Al和Ni-25at.-%Al混合粉末进行机械合金化,并对Ni3Al预合金粉末进行高能球磨,观察了粉末的金相组织,测定了粉末的硬度、平均直径和晶粒尺寸,并作了XRD物相分析。结果表明,经3h研磨,Ni-50at.-%Al混合粉末变成NiAl金属间化合物,其晶粒直径约5nm;经5h机械球磨,Ni-25at.-%Al混合粉末成为无序的亚稳定Ni固溶体,而Ni3Al预合 相似文献
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Na_2SO_4沉积物显著地加速Fe_3Al、Ni_3Al和Ti_3Al在600℃模拟燃气气氛中的腐蚀.腐蚀产物为M与Al的氧化物和硫化物的混合物.Fe_3Al和Ti_3Al的耐蚀性优于Ni_3Al因为Fe_3Al腐蚀产物中有一含高Al_2O_3的内层在Ti_3Al上则有由TiO_2和NbO_2组成的中间层而Ni_3Al的腐蚀产物的内层含有大量硫化镍有利于Ni的向外传输Na_2SO_4中添加NaCl对三种M_3Al的腐蚀过程无明显影响 相似文献
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SHS—铸造法制备Ni—Si金属间化合物的研究 总被引:3,自引:0,他引:3
自蔓延高温合成技术是一种新型的材料合成工艺。本文采用先进的SHS-铸造法进行了Ni-Si金属间化合物的合成,并对该方法所制备材料的组织结构,微量B的影响及材料的耐硫酸腐蚀性能等做了较详细地研究。 相似文献
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SUN Jian LIN Dongliang Shanghai Jiaotong University Shanghai China LIN Dongliang professor Department of Materials Science Shanghai Jiaotong University Shanghai China 《金属学报(英文版)》1993,6(5):332-336
Equilibrium equation of point defects in Ll_2 type intermetallic compounds was established tocalculate the relations of the concentration of antisite defects and vacancies and bulk composi-tion in Ni_3Al.The examination of temperature effects on the point defects cleared up the mis.understanding of the properties of the“constitutional point defects”in Ni_3Al. 相似文献
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The embedded atom type potentials and static relaxation method combined with steepest gra-dient computational technique have been used to simulate the grain boundary cohesive ener-gies,the distribution of electron density and stress field in the grain boundary,region,and oth-er related problems of[100],[110]and[111]symmetric tilt grain boundaries in Ni_3Al withdifferent grain boundary geometrical index and composition.Their relations with the segrega-tion or boron,behaviors or the grain boundary,and especially the stoichiometrical effect of Binduced ductility have also been studied and discussed. 相似文献
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GUO Jianting SUN Chao LI Hui GUAN Hengrong Institute of Metal Research Academia Sinica Shenyang China GUO Jianting Associate Professor Institute of Metal Research Academia Sinica Shenyang China 《金属学报(英文版)》1990,3(7):38-42
The effect of boron content(0 to 2.22 at.-% )on isothermal oxidation behaviour of Ni_3Al at750 to 1150℃ for 3 to 100 h has been studied.The results show that the isothermal oxidationkinetics of Ni_3Al with various B contents at different temperatures obeys the parabolic law.The compounds with 0.52 to 1.37 at.-%B show the best oxidation resistance.The morphologyand microstructure of the scales have also been investigated. 相似文献
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Ni3Al晶界结构的计算机模拟 总被引:2,自引:0,他引:2
本文运用嵌入原子法势函数和静态弛豫最陡梯度的计算方法,模拟[100],[110]和[111]轴一系列具有不同晶界几何参量及化学成分的Ni_3Al对称倾侧晶界原子结构、晶界能和晶界的内聚能、电荷密度分布及应力场等内容,并着重研究和讨论了它们与硼偏聚,Ni_3Al的晶界韧脆行为,特别是硼韧化的化学计量效应之间的关系。 相似文献
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采用电化学交流阻抗技术并结合物相分析技术研究了溅射CoCrAlY涂层对Ni3Al、Ni3Al-Fe金属间化合物在700℃熔融(Na,Li,K)2SO4中腐蚀行为的影响.结果表明,Ni3Al和Ni3Al-Fe的耐熔融盐腐蚀性能较差,其交流阻抗Nyquist图高频端表现为一曲率半径很小的圆弧,低频端为一直线,腐蚀反应受氧化剂的扩散所控制;施加CoCrAlY涂层后,Nyquist图则呈双容抗特征,发生了沿涂层缺陷的腐蚀;提出了交流阻抗模型并解析了其中的参数. 相似文献
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本文报道了铝当量为19-23at.-%的一系列铸造Ni_3Al基合金的显微组织和塑性及其与合金元素间关系的研究结果。表明,Hf、Ti和Zr显著地改变初生Ni_3Al(γ’)相的形态和分布并细化其尺寸,而Nb、W和Ta则不具有上述作用,在显微组织被细化的合金中,形成韧性的γ’-γ-γ’界面,消除了本质弱化的γ’-γ’脆性界面,初生相的尺寸可以控制在几十微米,表现出良好的塑性,尤其是中温塑性有较大改善。另外,组织细化的合金在无Cr时仍有可观的塑性,Cr对改善中温塑性有益,这可能是由于它改变合金中的γ相的数量和分布的结果。 相似文献
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ZHOU Yizhang ZHANG Tianxiang ZHU Yaoxiao HU Zhuangqi SHI Changxu Institute of Metal research Academia Sinica Shenyang China Assistant Professor Institute of Metal Research Academia Sinica Shenyang China 《金属学报(英文版)》1992,5(6):468-470
Investigation was made of the ductility and microstructure of a series of cast Ni_3Al-base al-loys,with 19—23 at.-% Al and other alloying elements.An obvious improvement onmorphology,distribution,amount and size of primary Ni_3Al(γ')intermetallic compound wasapproached by such alloying elements such as Hf,Ti and Zr,but no more by Nb,W and Ta.The formation of ductile γ'-γ-γ' boundaries in the alloys with refined primary γ'-phase caneliminate the weakened nature of brittle γ'-γ' boundaries,and reduce the size of primaryγ'-phase to tens of μm.Thus,the ductility of the alloys,especially at intermediate tempera-tures may be markedly improved.In addition,an alloy free from Cr is still significantlyductile,and only its structure is refined.The availability of Cr to improve the intermediatetemperature ductility seems to be due to the change of amount and distribution of γ-phase. 相似文献