金刚石/铝复合材料表面镀覆工艺研究

为了改善金刚石/铝复合材料表面的焊接性能,通过SEM-EDS、数字显微镜、粗糙度检测仪、接触角测量仪和热振、高温烘烤等检测方法,研究了活化、两次化学镀镍工艺对金刚石/铝复合材料表面形貌、成分、粗糙度、润湿性和焊接性能等的影响。结果表明,采用浸锌活化后进行一次镀镍、钯离子活化后进行二次镀镍、最后电镀金的方式可以实现金刚石/铝复合材料表面沉积连续完整的镀金层,镀层粗糙度可控制在0.4 ~ 0.7 m,结合力可耐400 ℃高温,满足金锡共晶焊接使用要求。     

线锯用金刚石微粉表面化学镀镍工艺及性能研究

金刚石微粉性能是提升金刚石线锯性能的关键因素。用化学镀方法在线锯用金刚石微粉表面镀镍,通过正交试验研究金刚石粒度、次亚磷酸钠浓度、镀液pH值和镀液温度对化学镀镀层沉积速率、镀层密度、镀层耐腐蚀性能、镀层致密度等性能的影响。结果表明：M1/2、M6/12、M20/30三种不同粒度金刚石微粉,在次亚磷酸钠浓度为25～35g/L、化学镀液pH值为3～11、化学镀温度为30℃～90℃时,针对镀层沉积速率、镀层密度和镀层耐腐蚀性的最佳工艺参数不同;不同粒度的金刚石微粉在相同工艺条件下化学镀镍,金刚石微粉粒度越大,镀层越均匀致密;金刚石微粉化学镀镍各工艺参数之间相互作用,共同影响镀层性能。对于不同粒度的金刚石微粉,各因素对镀层性能的影响权重不同,因此针对不同粒度、不同镀层性能需求的金刚石微粉应采取不同的镀覆工艺参数。     

电子封装中Au80Sn20焊料与镀层之间的相互作用及组织演变

电子元器件常通过镀层提高可焊性,主要包括Au、Ni、Cu、Au/Ni(Ti)、Au/Pt/Ti、Au/TiW等。Au80Sn20焊料是电子封装中的常用材料,文中总结了AuSn焊料与镀层之间的相互作用及组织演变。润湿性主要取决于AuSn焊料表面的氧化以及镀层在AuSn焊料中的溶解速度,Cu、Pt的原子结构与Au相似,以置换原子的形式溶解在AuSn焊料中,Ti与AuSn焊料之间的润湿性较差。AuSn焊料与镀层发生界面反应生成(Ni,Au)₃Sn₂、ζ-(Au,Cu)₅Sn、Au₅Sn、Ni₃Sn₄等金属间化合物（IMC）,IMC的形成和组织演变与焊点结构、工艺参数、服役条件等因素有关。     

金刚石颗粒表面化学镀镍及其在树脂磨具中的应用

通过化学镀镍工艺在金刚石颗粒表面镀覆一层金属镍，可一次镀也可多次镀。通过ＸＲＤ，ＳＥＭ，ＥＰＭＡ等分析，表明一次镀镀层形貌规则，多次镀镀层凹凸不平，镀层镍呈非晶态，形成Ｎｉ－Ｐ合金层。磨削试验表明，镀镍金刚石砂轮其耐磨性优于普普通金刚石砂轮，多次镀镍金刚石的更佳。     

铜、铜合金化学镀镍磷合金工艺

1前言化学镀镍磷合金以其独具的优良性能已被广泛应用于各行各业。化学镀镍磷合金,一般是在钢或铁基体上施镀效果较好,结合力最佳。为了扩大化学镀镍磷合金的应用领域,我们对铜、铜合金化学镀镍磷合金工艺进行了研究和探讨,经反复试验证明,此工艺是稳定的。众所周知,铜是不能催化诱发次亚磷酸盐化学镀镍的金属,所以铜和铜合金基体上镀镍磷合金的应用较少。有应用者是将工件与活性金属接触进行电化学诱发或用强还原剂如二甲基氨基甲硼烷处理表面。这些方法虽不改变镀层的性能,但基体与镀层的结合力不理想。为了改变这一弱点,我们在铜、铜合金…     

镀镍与镀铜对SiC_p/6063Al复合材料真空钎焊接头剪切强度的影响

采用表面金属化工艺在60%SiCp/6063Al复合材料表面制备镀铜层和镀镍层,然后对表面金属化处理前的复合材料进行真空加压钎焊,研究了镀镍和镀铜对复合材料钎焊接头剪切强度的影响。结果表明:复合材料表面镀层均与基体紧密结合;在570℃的钎焊温度下,随着保温时间延长,钎焊接头的剪切强度逐步增大;与表面镀镍及未镀金属的相比,表面镀铜复合材料接头的剪切强度更高,接头的剪切强度最高可达55.4 MPa,且其剪切断裂发生在钎料层和复合材料内部;镀镍会降低接头的剪切强度。     

化学处理对刀具表面金刚石涂层薄膜的影响研究

阐述了热丝化学气相沉积法(HFCVD)涂覆金刚石涂层时,采用Murakami溶液和HNO₃溶液进行化学预处理对刀具表面金刚石涂层薄膜的影响。采用扫描电子显微镜、能谱仪和拉曼光谱仪进行检测,结果表明,硬质合金中的黏结相Co元素和表面粗糙程度对涂层金刚石薄膜有较大影响,采用Murakami溶液浸蚀3min以上、HNO₃溶液浸蚀5min以上的刀具涂层表现出优越的性能,刀具寿命是未涂层刀具的2～4.5倍。     

金刚石/铝在微波功率组件中的应用研究

针对大功率微波组件中功率芯片对金刚石/铝等新型热管理材料的应用需求,文中开展了金刚石/铝表面可焊性镀层制备、功率芯片自动金锡共晶焊等工艺研究,制备了散热测试件,测试对比了在工作条件下以金刚石/铝和钼铜为热沉的功率芯片模块的实际散热效果。结果表明：在金刚石/铝表面上制备的Ni/Au 镀层均匀致密,附着力好,焊料在其表面铺展良好,芯片焊透率> 90%;在相同条件下,与钼铜相比,金刚石/铝上的芯片表面最高温度平均降低了6.3 ℃,具有更加优异的散热效果。     

推拉式小车法制备单层硒化钨薄膜

为了提升单层硒化钨（WSe₂）薄膜的制备质量，在传统化学气相沉积（CVD）法制备的基础上进行改进，通过引入推拉式小车来制备单层WSe₂薄膜，从而构造出可以调控沉积区域、精确控制生长时间，并可实现快速降温的生长方式。采用光学显微镜和原子力显微镜来表征制备材料的尺寸、荧光强度、形貌结构等特性，证明了利用推拉式小车法可成功制备出高质量的单层WSe₂薄膜。推拉式小车法可以稳定制备大面积、高质量、单层的WSe₂薄膜，为其在信息、能源、生物等前沿领域的应用提供参考。     

腐蚀性气体对金属镀层的影响

金属镀层耐腐蚀能力一般通过盐雾试验进行验证,大多数情况下忽略了腐蚀性气体的影响。随着产品使用时间的增加,镀层表面光泽会变暗,甚至出现深色斑点。电接触元器件表面长时间腐蚀后形成的腐蚀产物厚度不均匀,接触电阻发生变化,最终造成电接触故障,影响产品使用寿命。显然,气体腐蚀在产品外观以及电气性能上都造成了一定的影响。通过模拟气体腐蚀环境,验证铜镀银、铜镀锡、铜镀镍材料在一定浓度的NO2、SO2、Cl2、H2S气体环境下外观、镀层厚度和接触电阻的变化。试验结果表明,腐蚀性气体对外观影响从大到小为铜镀银、铜镀锡、铜镀镍,对接触电阻影响最大的是铜镀镍,铜镀银和铜镀锡无明显变化。     

SiCp/Al复合材料镀金工艺研究

SiCp/Al复合材料导电性差、膨胀系数低,尤其是不具备钎焊能力。为了满足封装壳体的良好钎焊性能,必须对其表面进行镀金改性处理。文中针对SiC体积分数高达60%以上的SiCp/Al复合材料进行镀金工艺研究,主要目的是解决镀金层与基材之间的结合力难题。通过工艺试验,采用工艺分步实施化学镀镍、热处理、电镀镍、电镀金步骤,得到的镀层表面光滑平整,没有明显的结瘤和夹杂,与基材的结合力强。该工艺作为SiCp/Al可焊性表面处理技术之一,对于其他铝基复合材料表面处理具有重要的参考价值。     

基于氮化铝HTCC基板的化学镀镍硼工艺研究

氮化铝(AlN)高温共烧陶瓷(High Temperature Co-fired Ceramic,HTCC)基板具有高的热导率以及与芯片匹配的热膨胀系数,是高功率多芯片组件首选的基板材料和封装材料。为了满足封装要求的良好钎焊性能,文中采用化学镀工艺在氮化铝HTCC基板钨导体表面沉积了化学镍钯金镀层。文中对化学镀镍溶液体系和高温热处理的工艺条件进行了研究,对化学镍层的厚度进行了优化。结果表明,高温热处理促使薄镍层向基板表面钨导体扩散,进而提高化学镀层与基底之间的附着力,镀层附着力良好,满足金丝键合和锡铅焊的要求,为微波高功率组件的研制提供了技术支撑。     

添加纳米MoS2镍-磷化学复合镀层的制备与微观形貌

运用化学复合镀技术制备出添加纳米MoS2的镍-磷复合镀层.研究了制备过程中镀液中分散剂种类、MoS2添加数量以及镀前试样表面粗糙度对复合镀层的影响.结果表明:十六烷基三甲基溴化铵(CTAB)可以很好地在镀液中分散纳米MoS2,镀液中添加纳米MoS2颗粒的最佳值是2.0 g/L;镀前试样表面粗糙度值过低不利于提高复合镀层中纳米MoS2的复合量.     

Corrosive Wear and Mechanical Properties of Ni/Al2O3 Micro- and Nanoparticulates-Reinforced Coatings on Ti-6Al-4V Alloy

Nanocomposite coatings can endow a plated surface with various properties such as wear resistance, high-temperature corrosion protection, oxidation resistance, and self-lubrication. This work studies the corrosion and corrosive wear resistance of electroplated nickel nanocomposite coatings on Ti-6Al-4V alloy in a Hank's solution, adding various concentrations of an Al₂O₃ powder in plating solution, with particle diameters of 20–30 nm and 1 μm for comparisons. The experimental results showed that the content of Al₂O₃ incorporated into the electroplated nickel composite coating increased with the concentration of Al₂O₃ powder in the electroplating solution, and increasing the surface hardness, corrosion, and corrosive wear resistance of electroplated nickel micro- and nanocomposite coatings caused smearing of the nodule boundary and elimination of voids in the deposits. The Al₂O₃ nanoparticulates were embedded and distributed more uniformly than the Al₂O₃ microparticulates in the nickel matrix after a heat treatment of 400°C, producing a more continuous and dense coated composite layer on the Ti-6Al-4V substrate. This phenomenon is responsible for the Ni/Al₂O₃ composite coating with superior surface hardness, providing high corrosion resistance and corrosive wear protection to the Ti-6Al-4V alloy substrate in Hank's solution.     

Wear prevention in molds used to mold boron filled elastomers

An investigation was conducted to identify surface coatings which would improve the wear characteristics of compression molds used to mold contoured parts from elastomers filled with crystalline boron particles. An analysis was made of the mode of wear present on the surfaces of a production mold, followed by selection and modification of a capillary rheometer as the test device. Test specimens were coated by electroplating, electroless plating, plasma spraying, chemical vapor deposition, sputtering and a fused salt process. Testing was conducted under conditions simulating those encountered in the production molding operation.Techniques used in evaluating the results included optical microscopy, scanning electron microscopy, transmission electron microscopy and surface profilometry. The results are expressed as a ratio of volumetric wear of the tested coating to that of unprotected mold steel.Results indicate that titanium diboride (TiB₂) applied by chemical vapor deposition provides wear resistance superior to plasma sprayed aluminum oxide mixed with titanium dioxide, plasma sprayed chromium oxide, electrodeposited chromium, electroless nickel containing synthetic diamond powder, chemical vapor deposited tungsten carbide (W/W₂C), aluminum oxide and aluminum oxide over chromium carbide. Sputtered titanium diboride was also superior to these coatings and to sputtered titanium carbide and boron carbide.     

化学复合镀层在NaOH中耐磨蚀性研究

研究了介质中NaOH浓度、镀层Cr2O3含量及热处理条件对低磷N i-P-Cr2O3化学复合镀层耐磨蚀性的影响,并与N i-P化学镀层进行了对比。结果表明:镀层的耐磨蚀性与介质中NaOH浓度呈线性关系,在任何NaOH浓度下复合镀层的耐磨蚀性均优于N i-P镀层;镀层Cr2O3质量分数在8%左右耐磨蚀性达到最佳值;经适当的热处理可显著提升镀层的耐磨蚀性。     

钛基化学镀耐磨涂层微动磨损性能研究

以提高钛合金抗微动磨损性能为宗旨,研究了化学镀Ni-Tl-B（NTB）三元合金及Ni-Tl-B/BN、Ni-Tl-B/SiC复合镀层制备工艺,利用X射线衍射技术、扫描电镜及能谱分析等手段,分析了三种镀层的结构,观察了镀层表面形貌,利用微动摩擦磨损试验机评价了化学镀处理对钛合金抗磨的影响,实验结果表明：该工艺得到的Ni-Tl-B、Ni-Tl-B/BN、Ni-Tl-B/SiC多元复合镀层表面光亮、质感均匀、镀层结合力良好,经过相同次数微动磨损试验,Ni-Tl-B镀层的耐磨性能比TA7及Ni-Tl-B/BN、Ni-Tl-B/SiC镀层好。     

Ni-P/n-MoS2复合镀层制备与摩擦学性能研究

以纳米MoS2颗粒为分散相,用化学复合镀的方法制备出Ni-P/n-MoS2复合镀层,并研究纳米MoS2颗粒在镀液中的添加量对镀层组织结构、显微硬度、纳米MoS2复合量和摩擦学性能的影响.结果发现:镀液中纳米二硫化钼的加入量为2.0 s/L时,得到的复合镀层中二硫化钼的分散效果最好,纳米MoS2复合量最大值为3.18%(质量分数),硬度最大值为HV653;磨损试验后,磨痕表面的二硫化钼质量分数最高可达7.8%,表明复合在镀层中的纳米二硫化钼在摩擦过程中被缓慢释放到表面,因而复合镀层表现出优异的自润滑和减磨性能.     

Electrical discharge abrasive drilling of hard materials using a metal matrix composite electrode

The main object of the present work was to develop an electrical discharge abrasive drilling (EDAD) methodology to remove the re-solidified layer through the grinding induced by a metal matrix composite electrode prior to the re-solidification of molten material. A metal matrix composite (Cu/SiC_p) electrode, with an electroless pretreatment of Cu coating on SiC_p to enhance bonding status between Cu and SiC_p, was made with a rotating device and this was employed to study the EDAD technology. The machinability of the mold steel HPM50 and tungsten carbide P20 was investigated by the combined technologies of EDAD. The machined surfaces of these materials were examined by scanning electron microscopy (SEM) and their surface roughness measured by a profilemeter. From the experimental results, it was found that the EDAD machining efficiency was three to seven times than that of normal EDM operation for mold steel. However, the efficiency improvement is hardly detectable for tungsten carbide. In addition, the surface roughness of both materials could be improved in comparison with that achieved after EDM.     

Electroless deposition and structure of Ni-MoSi2 composite coatings

Nickel-molybdenum silicide (Ni-MoSi₂) composite coatings were produced by a technique using an electroless nickel bath containing MoSi₂ in suspension. The operating conditions of the electroless deposition of Ni-MoSi₂ composite coatings and their structure were studied by X-ray fluorescence and X-ray diffraction. The mechanical properties of the composite coatings were determined. Some properties of the Ni-MoSi₂ composite coatings, such as oxidation resistance at high temperature, were investigated. These materials have potential for use in high-temperature applications involving oxidation resistance.