AZ91D镁合金直接化学镀镍工艺研究

采用磷酸和氟化钾为前处理酸洗液配方,以碱式碳酸镍为主盐,研究了AZ91D镁合金表面直接化学镀镍工艺。结果表明：得到的Ni-P镀层均匀、致密、无明显缺陷,其平均沉积速度约为0.3 μm /min;显微硬度值为达到4.8 GPa,磷含量为8.56 mass%。前处理过程中的酸洗步骤使镁合金基体产生粗糙的表面,从而改善了镀层和基体之间机械咬合的作用,增加了镀层的结合力.     

AZ91D镁合金的化学镀镍

使用硫酸镍作为化学镀镍磷镀液的主盐,直接在AZ91D镁合金基体上化学镀镍.使用扫描电镜和X射线衍射技术分析镀层的表面形貌和组织.化学镀镍磷镀层是致密的,无明显缺陷,其磷含量约为372 mass%.化学镀镍磷镀层的显微硬度值约为660 VHN,化学镀镍的沉积速度为23 μm/h.前处理过程中的酸洗步骤使镁合金基体产生粗糙的表面,从而使镀层和基体之间起到了互锁的作用,增加了镀层的结合力.     

AM50镁合金化学镀工艺研究

研究了压铸态AM50镁合金表面直接化学镀镍工艺,介绍了工艺流程、镀液成分和工艺参数,通过扫描电镜（SEM）和X射线衍射技术（XRD）对镀层组织结构、形貌和磷含量进行了检测分析。结果表明,得到的Ni-P镀层均匀、致密、无明显缺陷,其平均沉积速度为0.29μm/min,平均显微硬度为520HV,磷含量为11.24%（wt）,结合力为19N。     

镁合金化学镀Ni-P的工艺研究

由于镁合金在各介质中的不耐蚀性,其应用受到限制.为了在镁合金表面得到保护性镀层,通过多次实验研究镁合金化学镀Ni-P的镀液组成及不同参数对镀速的影响,测定了镀层的显微硬度、结合力和耐蚀性.盐雾实验和显微硬度的结果表明镀层具有较高的耐蚀性和硬度;热震实验和弯曲实验的结果表明镀层与基体具有良好的结合力.综合以上试验结论,试验得出的镁合金化学镀Ni-P层能满足一般工业对其性能的要求.     

镁合金表面化学镀Ni-P合金研究

镁是一种极活泼的金属,其合金具有优异的性能,是得到广泛应用的重要原因.然而,镁合金在各介质中的不耐蚀,其应用受到了制约.据文献报道,已有多种方法被应用到镁合金上,但效果都不很理想;而化学镀镍技术是近年来发展较快的一种表面处理方法.进一步探讨了在AZ91D表面上进行化学镀镍的研究过程:通过多次试验确定了镁合金的前处理方案,研究了在酸性条件下镁合金表面直接化学镀镍的一套工艺路线,配置简单,操作方便,避免了预镀中间层的麻烦.并且测定了镀层的厚度、显微硬度,观察了镀态的金相组织;热震实验和划痕实验的结果表明镀层与衬底具有良好的结合力.     

镁合金化学镀Ni-W-P合金的研究

为了在镁合金表面得到保护性镀层,研究了镁合金化学镀Ni-V-P的镀液组成和操作条件对镀速的影响,测定了镀层的厚度,显微硬度和结合力,利用X射线衍射(XRD)研究了镀层镀态的结构组织,镀层具有较高的硬度和优良的结合力,镀速由镀液组成的浓度控制.     

络合剂对AZ31D镁合金化学镀Ni-P合金的影响

以AZ31D镁合金为研究材料,研究了化学镀Ni-P工艺配方中络合剂对镀层的沉积速度、镀层表面形貌与结构、镀层成分及其各种性能的影响,获得了最佳工艺参数.结果表明,可以实现在AZ31D镁合金上直接化学镀Ni-P合金,并且其镀层表面光亮、均匀致密,镀层的显微硬度比AZ31D镁合金基体有明显的提高,镀层与基底的结合力良好.     

AZ91D镁合金化学镀镍磷研究

采用磷酸和氟化钾为前处理酸洗液配方,以碱式碳酸镍为主盐,研究了AZ91D镁合金表面直接化学镀镍-磷工艺。并应用金相截面法对该工艺的镀层沉积速度进行了检测分析;应用X射线衍射分析技术(XRD)、附带能谱仪的扫描电镜(SEM)、显微硬度测试仪以及划痕测试仪等对镀层的形貌结构、成分、硬度及结合力等作了检测与分析。该工艺所获得镀层不仅沉积速率稳定,而且表面良好、性能优良,具有很好的实际工业应用推广意义。     

AZ91D镁合金化学镀镍-磷新工艺研究

采用磷酸和氟化钾为前处理酸洗液配方,以硫酸镍为主盐,研究了AZ91D镁合金表面"两步法"化学镀镍(TSENP)的工艺。结果表明,在AZ91D镁合金上直接化学镀镍5分钟后可以实现以硫酸镍为主盐的第二步化学镀镍,镀层表面光亮、均匀致密,镀层的显微硬度比镁合金基体有了大大的提高,镀层与基底的结合力也比较优良,并且表现出了良好的耐腐蚀性能。"两步法"镁合金化学镀不仅镀层性能优良,而且有效降低了生产成本,提高了镁合金化学镀的实用性。     

前处理对镁合金化学镀镍结合力的影响

研究了镁合金多种前处理工艺对化学镀镍层与基体之间结合力的影响.采用弯曲法、锉刀实验法和划线划格实验3种镀层结合力测试方法,对化学镀镍层与镁合金基体之间结合力的优劣进行了定性评价.结果表明,采用一步法前处理工艺的试样,镀层与基体之间具有良好的结合力,金相显微观察发现镀层与基体之间具有最薄的中间过渡层.用浸锌工艺能较好地改善镀层与基体间的结合力.但镁合金浸锌工艺值得做进一步的研究.     

合金固溶度理论的进展(一)

对迄今已有的固溶度理论,作了具体介绍分析。并从所使用的理论方法,所描述的合金固溶度数目、理论预测与实验结果的符合速度,以及有无定量的方程式等方面对诸理论进行了详细比较,讨论了它们的优缺点。最后提出了今后工作的努力方向。文章分两部分发表,第二部分将刊于上海金属１９９９年第３期。     

合金固溶度理论的进展（二）

对迄今已有的固溶度理论,作了具体介绍分析,并从所使用的理论方法,所描述的合金固溶度数目,理论预测与实验结果的符合强度,以及有无定量的方程式等方面对诸理论进行了详细比较,讨论了它们的优缺点。最后提出了今后工作的努力方向。     

Plasma nitriding of Ti6Al4V alloy to improve some tribological properties

The present study was conducted to investigate the tribological and mechanical properties of plasma-nitrided Ti---6Al---4V alloy. Specimens were nitrided in an H₂---N₂ (1:8 ratio) plasma. The nitrogen concentration along the nitrided zone was obtained using the nuclear reaction analysis technique. The workpiece temperature was varied from 450 to 520 °C during the nitriding process. Pin-on-disc wear tests were carried out to evaluate the wear properties of the resultant samples and a ball-on-disc experiment was conducted to measure the friction coefficient. Microhardness tests, Scanning electron microscopy and X-ray diffraction were carried out to investigate the phases developed in the nitrided zone. It was found that the wear resistance improved considerably after the nitriding process. Three distinct layers were identified: (i) an inner layer where δ-TiN + -Ti₂N phases formed, (ii) an intermediate layer where -(TiN) with or without phase developed and (iii) an outer layer where precipitations were dominant.     

铝合金精炼理论要点和r艺原则

叙述了铝合金熔体精炼理论和工艺方面某些有说服力的研究成果,涉及“临界流速、“污染－净化动态平稳”概念,引出旋转喷吹净化工艺的优越性,提出了净化工艺应遵循的原则,指明了铝熔体中Ａｌ２Ｏ３和Ｈ２之间的相互依存关系。     

Embedded atom potential calculation of the Al–Pb immiscible alloy system

Embedded atom method (EAM) potentials for the Al–Pb immiscible alloy system were calculated along with some properties for f.c.c. Al, Pb and thermodynamic data for Al–Pb alloys. The calculated results for Al and Pb pure metals are in general agreement with the experimental values. The heat of solution for Pb in Al with our Al–Pb cross-potential was calculated and the result is close to that of ab initio calculated value. With the calculated heat of solution the solubility for Pb in Al after mechanical alloying was also calculated and the result is about 0.19 at.% Pb.     

冷却速度与Ce含量对快速凝固Al—Ce二元合金组织的影响

考察了冷却速度和成分对快速凝固Al—Ce二元合金组织的影响,结果表明,在相同冷却速度下,Ce含量少利于形成粒状弥散相;而成分一定时,提高冷却速度易于析出弥散度高的球形粒子。     

Interficial stability of Cu/Cu(Ru)/Si contact system for barrier-free copper metallization

Films of Cu/Cu(Ru) and Cu(Ru) were deposited on Si substrates by magnetron sputtering. Samples were subsequently annealed and analyzed by four-point probe (FPP) measurement, X-ray diffraction (XRD), transmission electron microscopy (TEM) and Auger electron spectroscopy (AES). After annealing at 500 °C, resistivity values of both systems decrease, but the reduction is more significant for Cu(Ru). Moreover, the resistivity values of annealed Cu(Ru) film are still greater than those of annealed Cu/Cu(Ru) film. XRD data suggest that Cu/Cu(Ru) film has higher thermal stability and Cu silicide cannot be observed up to 500 °C. According to TEM results, after annealing at 500 °C, the grain size of the Cu(Ru) film is smaller than that of Cu/Cu(Ru) film. In conjunction with AES, XRD, TEM analyses and sheet resistance measurement, it indicates that Cu/Cu(Ru) seed layers are potentially good for advanced Cu interconnects from the views of interfacial stability and low resistivity.     

High-temperature oxidation of a nickel base superalloy at different oxygen partial pressures

A series of oxidation tests were conducted for a nickel base superalloy, as these materials are used at high temperature in aggressive conditions, thus the influence of oxygen on their degradation mechanisms must be known. The material was treated for up to 150?h at 900 and 1000°C in a furnace able to control and maintain atmospheres with different partial oxygen pressures. The oxidation rate of the material was determined by gravimetric means. In all cases, the rate of oxidation followed parabolic regimes that depended on the value of oxygen partial pressure. The oxide scale formed was characterised by X-ray diffraction and scanning electron microscopy; these analyses revealed that the oxide scale consisted of an outer TiO₂ layer and inner Cr₂O₃ layer under all experimental conditions. Cross-section analyses indicated the development of internal oxidation and the presence of gamma-prime free zones.     

Relationship Between the Processing Parameters and the Properties of Semi-solid Processed Al Alloys

Relationship between the processing parameters and the properties of semi-solid processed Al alloys were studied and microstructure and mechanical properties of semi-solid processed Al parts for automobile application as a function of processing parameters were compared with those of die-cast parts and forged parts. In addition, the locations for the gate during the semi-solid processing were varied to elucidate the distribution of micro-porosities and resulting mechanical properties and the T6 heat treatment on the semi-solid processed part was performed so that the effect of heat treatment on the improvement of mechanical properties could be evaluated in terms of tensile strength, wear properties, etc. Microstructure of semi-solid processed Al part did not show any noticeable micro pores as compared to the microstructure of die-cast part. T6 heat treatment on A319 alloys has greatly improved the hardness as well as the wear resistance. Semi-solid processed A319 part showed slightly higher hardness val     

金属液对压铸模具腐蚀与防护的研究进展

简要介绍了国内外关于Zn,Al,Mg等压铸合金液的腐蚀机制及防护措施的研究进展,并对液态金属腐蚀的研究 方向提出一些建议和看法。