硼含量对化学镀镍硼合金层组织和性能的影响

本文研究了硼含量与化学镀镍硼合金层组织和性能的关系。结果表明,硼含量对镍硼合金层的表面形貌影响不大。硼含量低的合金层为晶态;随硼含量的增加,其结构逐渐转变为非晶态。晶态镍硼镀层的显微硬度比非晶态镀层的高,其耐磨性也优于非晶态镀层。     

非晶态镍磷合金晶化过程的研究

利用光学显微镜、透射电子显微镜、X射线衍射仪和显微硬度计,研究了非晶态镍磷合金镀层晶化过程及镀层的组织和性能.结果表明: 200～260℃加热,镀层的局部区域已发生晶化;280℃热处理后晶化过程加快;400℃热处理后晶化完全;500℃加热处理后晶粒开始长大.表明非晶态Ni-P合金的晶化在200～400℃温度范围内进行,晶化过程中,弥散析出的Ni3P相具有调幅结构.大量高硬度的Ni3P相弥散析出,使镀层硬度大大提高.     

非晶态镍磷合金的晶化结构和性能

本文研究了影响化学沉积层结构和性能的各种因素,如化学成分、退火温度和时间等,并提出了要使非晶态镍磷合金在晶化后具有较为优越的性能,其含磷量为12～15%(at),退火规范是在400℃时保温1小时。     

化学镀Ni—W—P非晶态合金的晶化及其影响

通过ＤＳＣ、ＸＲＤ分析和镀层性能测试,研究了化学沉积Ｎｉ－Ｗ－Ｐ非晶态合金的晶化过程。结果表明,钨的共沉积提高了化学镀镍层的热稳定性。晶化过程激活能为１３３．５７６ｋＪ／ｍｏｌ,晶化过程合金结构按非晶态－混晶态－结晶态的顺序演变。随着结构的变化,镀层的硬度的耐蚀性了也发生的相应的变化。     

铝合金化学镀镍磷合金镀层的组织和相结构

介绍了铝合金化学镀镍磷合金镀层的初期析出行为、组织和相结构。镀态下，镀层截面组织为黑白分明的层状组织，平面组织呈同心环状。低磷镀层的相结构是磷在镍中的过饱和固溶体，而高磷镀层为非晶态镍磷合金。随着加热温度的升高，低磷镀层的相结构是磷在镍中的过饱和固溶体，而高磷镀层为非晶态镍磷合金。随着加热温度的升高，低磷镀层首先析出ＮｉｘＰｙ，然后析出Ｎｉ３Ｐ相。高磷非晶态镀层首先晶化转变成ＮｉｘＰｙ相和Ｎｉ３Ｐ     

纳米氧化铝粒子对化学镀镍-磷合金晶化行为的影响

通过化学复合镀制备纳米氧化铝粒子增强镍-磷合金复合镀层,并对所得表面纳米复合材料进行透射电镜显微分析(TEM)、扫描电镜显微分析(SEM)、X射线衍射分析(XRD)、能谱成分分析(EADX)和示差扫描量热分析(DSC).结果表明:纳米粒子在复合镀层中含量较高且分布均匀;所得镀层是中磷非晶态.纳米粒子使得复合镀层晶化温度降低,显微硬度值比镍-磷合金镀层明显提高.在一定条件下热处理,复合镀层晶化,硬度值大幅提高.     

化学成分与时效处理对镍磷耐磨涂层性能选择的影响

本文研究了化学成分与时效处理对镍磷涂层性能的影响,结果发现,沉积态下低磷涂层硬度、耐磨性高于高磷涂层,时效处理后,高磷涂层则具有更高的硬度与耐磨性。根据镍磷合金的成分与组织状态来选择镍磷耐磨涂层。     

Zr-基块体非晶合金近玻璃转变温度热处理后的组织与性能

选择在非晶合金的玻璃转变温度与晶化起始温度间的较低温度对Zr57Cu15.4Ni12.6Al10Nb5块体非晶合金进行了等温热处理，用X射线衍射、扫描电镜、显微硬度计与压缩试验，研究了等温热过程中非晶合金的组织结构变化及其对显微硬度与压缩性能的影响。结果表明，在近晶化温度下，一定时间的热处理会引起非晶合金的晶化。而在近玻璃转变温度下，较长时间的热处理也不会引起非晶合金出现明显的晶化和组织变化；但随着热处理时间的增长，合金的显微硬度有增大趋势，合金的压缩强度明显下降，断口形貌变化显著，断裂方式也逐渐由非晶态的断裂方式向晶态的断裂方式转变。     

化学成分与时效处理对镍灰耐磨涂层性能选择的影响

本文研究了化学成分与时效处理对镍磷涂层性能的影响。结果发现,沉积态下低磷涂层硬度、耐磨性高于高磷涂层,时效处理后,高磷涂层则具更高的硬度与耐磨性,根据镍磷合金的成分与组织状态来选择镍磷耐磨涂层。     

镍磷非晶纳米晶复合镀层的制备及其耐蚀性

对电沉积12．3％P（质量分数）镍磷合金进行热处理，部分晶化获得非晶纳米晶复合镀层。利用X射线衍射仪、透射电镜和高分辨透射电镜分析镀层的结构。结果表明，镀态时镀层呈典型的非晶态结构，控制热处理工艺可得到非晶纳米晶的复合镀层。通过动电位极化曲线（3．5％NaCI溶液）测定，得知部分晶化的镀层耐蚀性得到改善。由于具有少量纳米晶相镶嵌于连续非晶相上，非晶纳米晶复合结构的镍磷合金镀层耐蚀性优于非晶态镍磷合金镀层。     

Mg94TM(Zn,Cu,Ni)2Y4合金的铸态组织及摩擦磨损性能

利用普通铸造法制备了Mg94TM(Zn,Cu,Ni)2Y4三种合金,并研究其铸态组织特征、物相组成及耐磨性能.Mg94Zn2Y4和Mg94Cu2Y4合金组织呈现[明显的树枝晶结构,而Mg94Ni2Y4以等轴晶为主;Mg94Cu2Y4和Mg94Ni2Y4两种合金的金属间化合物组成要比Mg94Zn2Y4合金复杂.三种合金材料中,Mg94Zn2Y4合金的硬度最低,耐磨性最差,其磨损机制均主要表现为犁沟磨损、粘着磨损和氧化磨损.     

Electroless deposited ternary alloys: third element chemical state,localisation and influence on the properties. A short review

Electroless deposited ternary alloys have been reviewed in relation to the chemical state of the third element, its localisation and the possible influence of these on alloy properties. Three types of electroless Ni–W–P, Co–W–P and Ni–Zn–P coatings have been investigated. Low P deposits are nanocrystalline and those with higher P content are amorphous. X-ray diffraction has proved the localisation of W, Zn and P along the nanograin boundaries. The localisation of Zn along with P has also been confirmed by transmission electron microscopy combined with energy dispersion spectroscopy. Analysing the X-ray photoelectron spectroscopy (XPS) spectra it has been found that within the coatings W is in elemental form, whereas Zn is partially oxidised. XPS data also show that the crystalline structure promotes the surface oxidation to a higher extent than in the case of amorphous structure. The wear resistance of nanocrystalline Ni–W–P coatings is much higher. A lower corrosion resistance of amorphous Ni–W–P coatings has been found by weight-loss method during long-term immersion in 5% NaCl. It is illustrated that in addition to the composition and structure, the properties depend on the distribution and chemical state of the alloy components.     

SiC对Ni-W合金耐蚀耐磨性能的强化作用

为提高严苛海洋环境下金属机件的服役性能,本文通过电沉积方法制备了Ni-W和Ni-W/SiC复合镀层。利用扫描电子显微镜（SEM）、能谱分析（EDS）和X射线衍射（XRD）等技术研究了SiC对Ni-W合金微观结构和性能的影响,采用电化学方法研究了复合镀层在3.5% NaCl溶液中的耐蚀性能,以探讨其海水综合防护性能。研究表明,经表面处理的SiC可诱导形核促进晶体生长,使Ni-W合金晶粒变细,镀层完整致密。SiC纳米颗粒均匀分布在Ni-W/SiC中,可有效提高镀层硬度及耐磨性,同时Ni-W/SiC也具有比Ni-W合金更好的耐蚀性能,在多因素交互作用的海洋环境中将具有更长的防护寿命,具有良好的应用前景     

氧化铝增强化学镀镍基合金涂层的性能

研究了氧化铝微粒增强化学镀镍 (铜 ,磷 )合金涂层的性能。在Al2 O3和Ni(Cu ,P)合金共沉积过程中 ,Al2 O3在溶液中的加入量增多 ,Al2 O3在镀层中的复合量逐渐提高 ;Al2 O3的复合 ,显著改变了Ni(Cu ,P)合金沉积层的组织与性能 ,使Ni(Cu ,P) Al2 O3复合材料具有更高的硬度、耐磨性和抗氧化性。     

激光熔覆制备高熵合金涂层的研究进展

激光熔覆技术具有高的冷却速度、低的稀释率、涂层与基体冶金结合等优点,采用激光熔覆技术制备耐磨性和耐腐蚀好的高熵合金涂层是近几年高熵合金领域的研究热点之一。首先概括了激光熔覆技术制备的高熵合金体系及组织结构特征,大多高熵合金涂层以固溶相为主,少数合金涂层形成了非晶相,与熔炼制备高熵合金块体材料相比,涂层组织具有均匀、细小致密等特点。然后介绍了涂层的性能特征,涂层具有较高的硬度、良好的耐磨性,同时指明高耐磨性涂层不仅具有高的硬度,同时还需要具有一定的塑韧性。涂层合金中大多包含有Al、Cr、Si和Co等形成稳定氧化膜的元素,呈现优异的抗腐蚀性能。随后重点概述了合金元素（Al、Mo、V、Ti、B、Ni、Nb和Cu等）、熔覆工艺参数（激光功率、扫描速度和预制层粉末厚度）和热处理工艺对涂层组织结构和性能的影响规律。其中,熔覆工艺参数对涂层组织结构和性能的影响研究相对较少,将是未来研究的重点内容之一。最后对激光熔覆技术制备高熵合金涂层存在的问题和未来的研究方向做了展望。     

TC4钛合金表面化学镀Ni-P合金耐磨层研究

利用化学镀方法在TC4钛合金表面成功制备结合力良好的Ni-P合金耐磨层,研究了提高镀层结合力的方法,结合SEM、XRD、EDS等现代物理分析方法分析了不同温度热处理后镀层的组织结构,从而建立不同热处理温度、镀层结构与镀层硬度和耐磨性能的关系。结果表明:二次浸锌活化方法和热处理能显著提高镀层与基体的结合强度,经600℃热处理后镀层结合力达到35N。基材的硬度HV为3780MPa,磨损量为9.6mg,镀态镀层的硬度HV为5760MPa、磨损量为7.7mg。随着热处理温度升高Ni3P相增多,该相的弥散分布使镀层硬度增加,最高硬度HV达到9790MPa,但400℃后硬度降低,这是由于Ni3P相随着热处理温度的继续升高而发生偏聚,使弥散强化程度下降;镀层的磨损量随着热处理温度的升高而减小,说明耐磨性能随着热处理温度的升高而增强,600℃热处理后,虽然镀层晶粒长大、粗化及镀层硬度降低,但此时镀层晶格的完整性最佳,镀层塑性和韧性提高,所以耐磨性能最好。     

块体非晶合金Fe-Ni-P-B-Ga的制备与性能

采用助熔剂净化和铜模铸造相结合的工艺，用工业纯原料制备出块体(Fe40Ni40P14B6)100-xGax(x=0-8)合金，样品为直径3mm的圆柱体或宽6mm、厚1mm的片材，长度都在10至15mm左右，XRD与DSC分析表明，x=4—6时易于形成非晶合金，测试表明，这些非晶合金具有优异的耐腐蚀性能和软磁性能，显微硬度测试表明，对相同成分合金，非晶态的显微硬度值比晶态的低，适量Ga的加入，提高了Fe—Ni—P—B合金的非晶形成能力。     

Characteristics of Tribaloy T-800 and T-900 coatings on steel substrates by laser cladding

CoMoCrSi alloys, mostly known as Tribaloy® family, combine well-known outstanding properties in terms of wear and corrosion resistance as well as in terms of mechanical strength. Compared to other wear resistant alloys, their performance is due to the presence of hard Laves phases rather than intermetallic carbides. Among the Tribaloy family, the T-800 alloy offers the best performance as a result of a higher amount of primary Laves phases. However, as a consequence of the brittle nature of these hard phases, the deposited alloy may present a relatively low resistance to crack initiation and propagation, particularly in laser cladding processing where thermal stresses are significant. A reduction in the volume fraction of these hard phase may be achieved by replacing some of the Laves phase components in the alloy (Co, Mo, Si) by Ni (T-900 alloy). Alternatively, it has been suggested that the addition of Fe could also lead to a significant reduction. The Fe addition can easily be accomplished in laser cladding process by dilution of the T-800 coating with the steel substrate. In this work a comparative study of microstructure, hardness and cracking susceptibility of low and high diluted T-800 and T900 coatings deposited by laser cladding is presented. A lower cracking ratio is obtained for the T-900 coatings at the cost of a lower hardness and wear resistance. No noticeable effect on the cracking susceptibility of the T-800 is found due to dilution with the substrate. However a change in its microstructure is observed giving superior hardness and wear resistance.     

Wear and corrosion properties of laser cladded Cu47Ti34Zr11Ni8/SiC amorphous composite coatings on AZ91D magnesium alloy

To improve the wear and corrosion properties of AZ91D magnesium alloys, Cu-based amorphous composite coatings were fabricated on AZ91D magnesium alloy by laser cladding using mixed powders of Cu47Ti34Zr11Ni8 and SiC. The wear and corrosion behaviours of the coatings were investigated. The wear resistance of the coatings was evaluated under dry sliding wear condition at room temperature. The corrosion resistance of the coatings was tested in 3.5% （mass fraction） NaCl solution. The coatings exhibit excellent wear resistance due to the recombined action of amorphous phase and different intermetallic compounds. The main wear mechanisms of the coatings and the AZ91D sample are different. The former is abrasive wear and the latter is adhesive wear. The coatings compared with AZ91D magnesium alloy also exhibit good corrosion resistance because of the presence of the amorphous phase in the coatings.     

稀土元素对AgCuNi合金材料组织性能影响研究

银铜镍系合金主要用作直流微电机换向器材料。采用金相显微镜(OM)、扫描电镜(SEM)、显微硬度仪、拉力试验机,以及真空熔炼等分析技术手段,研究了La、Ce等稀土元素对Ag-4Cu-0.5Ni0.5合金组织和性能的影响。结果表明,混合稀土的加入可对合金的显微组织进行细化和第二相球化,产生细晶强化和弥散强化的作用,合金的硬度、强度、摩擦磨损性能得到进一步地提高,有助于改善合金材料的耐磨性。