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1.
An investigation is reported of the constitution of the 75 at % nickel section of the Ni-Cr-Al-Mo system in the temperature range 1523 to 1073 K. Alloys in the region 10 to 20 at % Al were annealed at 1523, 1273, and 1073 K, respectively, and subjected to electron microprobe analysis, X-ray diffraction, and microscopical and hardness examination. Constitutional data are presented as partial isothermal sections and as vertical sections. At 1523 K the section consists only of fields containing ,+ and , the last mentioned phase being predominant. With decreasing temperature the and + fields increase in extent. Also, the NiMo and Ni3Mo phases were encountered in the ternary Ni-Al-Mo alloy studied. The quaternary + alloys showed small lattice mismatch values, i.e. up to 0.25%. Raft like morphologies of were found in the quaternary alloys, resulting from directional coarsening. Observations of as-cast structures are also reported. 相似文献
2.
A kinetic model based on the principle of maximum degradation rate of the total system free energy, MDR law using thermodynamic data, is proposed and successfully applied to the selection of the first intermetallic compound (IMC) phase in Cu/Sn and Ni/Sn diffusion couples. The first phases predicted with this model for Cu/Sn and Ni/Sn are Cu6Sn5 and Ni3Sn4, respectively, resulting in good agreement with experimental observations. 相似文献
3.
An investigation is reported of the 75 at% nickel section of the Ni-Cr-Al-Ru system at 1523 and 1273 K. Constitutional data obtained by electron probe microanalysis, X-ray diffraction and microscopical examination are presented as partial isothermal sections. At 1523 K, the major part of the section consists of phase, while the aluminium-rich region contains a and+ region; the extent of the solid solution of chromium and ruthenium in totals ~ 4 at%. The ruthenium-rich corner of the section shows a two-phase region consisting of + ruthenium-rich solid solution. At 1273 K the,+ and + ruthenium regions increase in extent. The/ mismatch values in the equilibrated alloys studied lie in the range ~ –0.08 to –0.39%. Constitutional features of as-cast alloys are also reported. 相似文献
4.
《Thin solid films》1986,143(3):249-257
The process of interdiffusion and compound formation in Mo/Pd/Si thin films was studied between 250 and 750°C via sheet resistance measurements, X-ray diffraction, Rutherford backscattering spectrometry and Auger electron spectroscopy. The results indicate that thermal annealing of the Mo/Pd/Si thin film couples between 250 and 475°C lead to PdSi interaction, Pd2Si compound formation and consequently a small increase in the sheet resistance. In contrast, exposure of the Mo/Pd/Si thin films to temperatures higher than 475°C lead to MoPd2Si interaction in addition to PdSi interaction, MoSi2 compound formation and a dramatic increase in the sheet resistance. The influence of interdiffusion and compound formation on the interface morphology in the Mo/Pd/Si system was studied, and the implications of these observations to a very-large-scale integration contact metallization utilizing an Mo/Pd2Si/Si system are discussed. 相似文献
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By X-ray analysis,TEM and SEM methods the phase composition,microstructure,and deviation from stoichiometric composition were investigated for the Ni3Al intermetallic compound obtained by cast and self-propagation high-temperature synthesis under compression with followed homogenization anneal,with the Al concentration being 24.0 and 25.0 at.pct with and without B(0.5 at.pct).It was discovered that in SHS intermetallic alloys an average local deviation from stoichiometric composition is significantly more than in the cast alloy.Dependence of the local deviation from the stoichiometric composition on the distance has a zig zag nature at the level of the grain groups.Deviation from the stoichiometric composition at the boundaries of the general type is less than at the boundaries of the special type.When the intensity of boundary migrations of the general type decreases,the degree of deviation from the stoichiometric composition increases.There in correlation between the solubility of B in the crystalline lattice of the Ni3Al phase and the value of the deviation from the stoichiometric composition in the grains.When the B concentration in a solid solution increases,the deviation from stoichiometric composition decreases. 相似文献
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对Ni3Al基合金结构焊接的工艺进行了研究,对焊缝显微组织及性能进行了分析,结果表明:采用合理的焊接工艺参数,用Ni818焊条能够实现Ni3Al工个的结构焊接。 相似文献
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An investigation of the phase growth kinetics and identification of the phases formed as a result of reactive diffusion in the MoNi thin film system were carried out by electrochemical anode dissolution, standard transmission electron microscopy and electron diffraction. 相似文献
10.
通过激光技术合成单Ni3Al相金属间化合物,利用电化学方法及盐雾试验研究了Ni3Al金属间化合物在Na Cl溶液中的腐蚀行为特征、耐腐蚀性能及腐蚀机理。结果表明:激光合成Ni3Al金属间化合物在不同浓度的Na Cl腐蚀介质中均能形成保护性钝化膜,当Na Cl溶液浓度低于2%时,钝化膜具有良好的稳定性和耐腐蚀性能。当Na Cl溶液浓度高于3.5%时,钝化膜产生活化溶解,稳定性下降,Ni3Al金属间化合物表面形成点蚀坑,并且随腐蚀介质浓度增大,腐蚀加剧。Ni3Al金属间化合物表面点蚀坑边缘规整、腐蚀界限清晰,腐蚀机制为典型的晶内腐蚀,腐蚀过程中未形成应力腐蚀微裂纹等破坏性缺陷,具备在沿海湿热盐雾环境下使用的潜在价值。 相似文献
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Hanliang ZHU Zhiqiang LI Bosheng SHANG Wenfeng MAO Chunxiao WANG Shiqiong LI Jianwei ZHANG 《材料科学技术学报》2001,17(1):119-120
Superplastic properties and microstructural evolution of a Ti-24Al-14Nb-3V-0.5Mo (at. pct) intermetallic alloy were studied. Optimum superplastic properties were obtained for temperatures in the interval 960℃≤5 T≤5980℃. The apparent activation energy in the superplastic regime was determined and the deformation mechanism was also discussed. Based on the studies, a curve panel with three sheets sandwich structure was fabricated successfully. The microstructures corresponding to different strain in the part were also studied. 相似文献
12.
Jeong So-Eun Yoon Jeong-Won 《Journal of Materials Science: Materials in Electronics》2022,33(9):6616-6626
Journal of Materials Science: Materials in Electronics - In this study, the transformation of the intermetallic phase and high-temperature durability of the 30Ni–70Sn (wt%) transient liquid... 相似文献
13.
H.W. Tseng 《Materials Letters》2008,62(23):3887-3889
Ag3Sn compound formation was observed to evolve from the Cu side to the Ni side in Ni/Sn5Ag/Cu solder joint upon reflow process. The transformation of the interfacial compound phase at the Sn5Ag/Ni interface, i.e., from Ni3Sn4-based compound to Cu6Sn5-based compound, changes the interfacial energy state, which is the main driving force for the evolution of Ag3Sn compound formation. The evolution consequence of Ag3Sn compound suggests that Sn5Ag/(Cu,Ni)6Sn5 interface is the best energy-preferential heterogeneous nucleation site for the Ag3Sn compound phase, comparing to the Sn5Ag/Cu6Sn5 interface and the Sn5Ag/Ni3Sn4 interface. In addition, the lower Cu concentration near the Ni side is another added driving force for the heterogeneous nucleation of Ag3Sn phase at Sn5Ag/(Cu,Ni)6Sn5 interface. 相似文献
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The ordered f c c intermetallic compound Ni3Si was mechanically milled in a high-energy ball mill. The severe plastic deformation produced by milling induced transformations with increasing milling time as follows: ordered f c c disordered f c c nanocrystalline f c c. The structural and microstructural evolution with milling time was followed by X-ray diffraction, TEM, hardness tests, and differential scanning calorimetry (DSC). Complete disordering occurred at milling times of 2 h and kept the saturated H of the DSC peak in the range of estimated enthalpy even after 60 h milling. The structural development during milling of the f c c solid solution for Ni3Si was presumably dominated by the formation and refinement of a dislocation cell structure into microcrystallites which eventually reached nanometre dimensions. 相似文献
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Polycrystalline samples of Ni4Mo have been examined at various stages of isothermal ageing at 700° C. The mechanical properties were measured on initially disordered samples at various stages of the ordering process. These properties were correlated with microstructural observations such as domain size, degree of order and fracture characteristics. The correlations are rationalised in terms of a model for the ordering process and its effect on dislocation motion. 相似文献
16.
Mo添加对Ni3Al-TiC润湿特性的影响机制研究 总被引:2,自引:0,他引:2
采用2AP-LEITZ高温显微镜对TiC-Ni3Al的润湿接触角进行了实验测定,着重探讨了Ni3Al对TiC的润湿特性以及Ni3Al中添加少量Mo的影响机制.结果表明,TiC与Ni3Al之间具有良好的润湿性能.5wt%Mo的添加使Ni3Al向TiC基板浸渗的深度增大,并与TiC颗粒发生固溶反应置换出部分Ti,在其周围形成一个含Mo的壳层.在这个壳层里,Ti、Mo进一步与Ni3Al固溶,这些反应降低了液-固表面张力,导致了润湿接触角的下降,从而改善了TiC-Ni3Al的润湿性. 相似文献
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0 Introduction
The Ni3 Al intermetallic compound is of great interest because of its corrosion-resistance, and high melting point. However, it is difficult to make the intermetallic compound using the ordinary method. 相似文献
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Isothermal sections of the Ni-Cr-Al-W system have been investigated at 75 at % Ni and temperatures of 1523 and 1273 K, by means of phase compositional analysis, X-ray diffraction and microscopical examination. The alloys studied lay in the range 2.5 to 10 at % Cr, 12.5 to 20 at% Al, 2.5 to 6.25 at % W, The phases formed were, and the bcc solid solution based on tungsten (designated
2). The maximum extent of the region was found to be 3 at % each of chromium and tungsten. Preferential partitioning of tungsten to occurred. Study of an Ni-10Cr-12.5Al-2.5W alloy aged at 1273 and 1073 K, after quenching from 1573 K, showed that changes in and compositions and lattice parameters occur as a function of ageing time. 相似文献
19.
目的研究纳米Ni对SnAg0.3Cu0.7无铅焊锡膏的焊点界面IMC影响。方法采用在助焊剂中添加纳米Ni颗粒,制备出纳米Ni颗粒增强的SnAg0.3Cu0.7焊锡膏,分析纳米Ni在150℃时效中对IMC的影响。结果在150℃时效中界面IMC的厚度随着时效时间延长而增大,形貌变成平缓层状;添加Ni质量分数为0.025%时,对界面IMC几乎无影响,当添加质量分数为0.05%和0.1%的纳米Ni能促进IMC的生长,但抑制Cu3Sn层的生长。结论通过添加纳米Ni颗粒,在150℃时效中可促进IMC的生长,抑制Cu3Sn层的生长。 相似文献
20.
Intermetallic phases formed in the aluminium-base alloys of composition 4 to 14 mass % Si and 20 to 35 mass % Fe were studied by electron probe microanalysis and X-ray diffraction. In the non-equilibrium (as-cast) samples-AlFe,-AlFeSi,-AlFeSi and-AlFeSi phases were identified. It was established that the-AlFe phase contained 1 to 6% Si causing a change of lattice parameters. In the quasi-equilibrium (heat-treated) state the chemicai composition of the-AlFeSi is within 6 to 9.5% Si and 32 to 36% Fe and that for the-AlFeSi within 14 to 16% Si and 27 to 28% Fe. On the basis of the chemical compositions of the intermetallic phases, the 600° C isotherm section of the aluminium-side corner of the AlFeSi-system was revised. 相似文献