铝合金化学镀镍磷合金结构和性能

针对质子交换膜燃料电池双极板的需要,以铝合金为基体材料,采用碱性和酸性双溶液体系化学镀镍磷合金.采用电子探针方法测定了镀层中镍磷含量,X衍射方法研究了热处理对镀层结构的影响,伏安法研究了热处理对镀层耐蚀性的影响.试验结果表明,热处理明显影响镀层的结构和耐蚀性,对于P含量为12.1%（质量）的镍磷合金镀层,经过200～250℃热处理后,晶化不明显但耐蚀等性能明显改善,可以用作质子交换膜燃料电池双极板.     

热处理对电刷镀镍-磷镀层性能的影响

电刷镀非常适合于大型模具的现场修理,在常用刷镀层中,镍层、镍钨钴合金及某些复合刷镀层一般难以满足大型模具的综合性能要求,而镍磷镀层是一种通过热处理可以改善其性能的镀层.作者通过研究热处理对不同磷含量的镍-磷镀层硬度、耐磨性、耐蚀性及结合强度的影响规律发现,含磷2%左右的镍磷镀层通过400℃左右的热处理后具有最佳的硬度、耐磨性和结合强度,而含磷10%左右的镍磷镀层经600℃左右的热处理后具有最佳的耐蚀性能,这可以为电刷镀在大型模具的修理方面针对不同的使用要求提供合适的镀层和热处理方法.     

碳钢化学镀镍-铜-磷合金及耐蚀性研究

采用化学镀的方法在碳钢表面进行镍-铜-磷三元合金化学镀。研究了pH值、温度、硫酸铜含量等条件对沉积速度、铜含量、耐蚀性以及镀层表面形貌的影响。研究结果表明,温度为90℃,镀覆时间为1h,镀液的pH值为7.5,硫酸铜浓度为1.2g/L时,镀层的耐NaCl溶液腐蚀性良好,且耐蚀性优于镍-磷化学镀层.     

化学镀镍磷合金层的组织与性能

研究了四种不同磷含量的镍磷合金镀层结构以及热处理对组织和性能的影响.结果表明,随磷含量的增加.镀层的结构由晶态→晶态→非晶态→非晶态变化.镍磷合金镀层经时效热处理后,晶态合金镀层从过饱和固溶体中析出新相,非晶态合金镀层发生晶化过程,同时析出新相.315℃以上温度时效处理后,可得到镍和Ni_3P两相组织。经加热时效处理后,镀层的硬度随加热温度的升高呈下抛物线型变化,在400℃时效30分钟可得到硬度的极大值.镀态镀层的耐磨性较差,经时效处理后镀层的耐磨性能提高,600℃时效处理的镀层具有较好的耐磨性。     

化学镀镍磷合金的钝化及孔蚀

本文研究了化学镀镍磷合金的钝化及孔蚀。结果表明：磷含量直接影响化学镀镍磷合金的钝化性能，随磷含量增加，合金镀层钝化膜形成速率加快，高磷合金为非晶结构，钝化性能优异。提高溶液ＰＨ值，有利于合金的钝化，溶液中氯离子对镍磷合金钝化具有破坏作用。合金中磷的不均匀分布及胞界等的存在，使得镍磷合金在氯离子作用下产生孔蚀，提高合金中磷含量及采用双层镀镍磷合金的方法，可改善合金的抗孔蚀性能。     

脉冲镀非晶态镍磷合金

通过实验，分析讨论了在同一脉冲平均电流密度下，脉冲导通时间ｔｏｎ和关断时间ｔｏｆｆ对非晶态镍磷合金镀层镀速、结合力、磷含量、硬度及耐蚀性的影响。并与直流镀层进行了对比。实验结果表明脉冲镀层优于直流镀层。     

磷含量对化学镀镍——磷合金性能的影响

本文采用酸性化学镀镍－－磷合金镀液，通过改变还原剂浓度，制备一系列不同磷含量Ｎｉ－Ｐ合金镀层研究磷含量对镀层性能的影响。表明镀层耐蚀性、硬度等性能与磷一有直接关系。     

热处理对Fe－Cr－Ni合金镀层结构性能的影响

通过对Ｆｅ－Ｃｒ－Ｎｉ合金电刷镀层的结构、结合力、硬度和耐蚀性的测试，探讨了热处理对该合金镀层结构性能的影响．试验结果表明，经１０５０℃固溶处理可使镀层结构由镀态的微晶体＋非晶态结构转变为γ单相结构，使镀层的结合力和耐蚀性都有提高．镀层的硬度随热处理温度的升高呈山形变化，温度为４００℃时，硬度由镀态时的ＨＶ４５０增至ＨＶ９４０（最大值），故有利于提高镀层的耐磨性．     

化学镀非晶Ni-P合金镀层耐蚀性研究

采用化学镀方法在碳钢上沉积非晶Ni-P合金镀层(10.90wt.％),考察Ni-P合金结构、性能及热处理温度对耐蚀性的影响.结果表明:在10％ HCl溶液中,非晶Ni-P镀层具有较好的耐蚀性;热处理影响镀层的耐蚀性,非晶Ni-P镀层经200℃热处理后,可使耐蚀性能提高37％,热处理温度达到300℃和400℃时,镀层分别出现亚稳相和稳定相,耐蚀性能降低,但耐蚀性仍优于镀态Ni-P镀层.     

PEM燃料电池操作性能实验分析

目的研究质子交换膜燃料电池运行中电池的工作压力、反应气体流量对电池性能的影响．方法对质子交换膜电池单体在不同工作压力、不同气体流量下的电池性能变化做了测试并将得到的实验数据进行对比及理论分析．结果通过实验得出了压力和气体流量对电池性能影响的规律曲线．结论PEM燃料电池的性能随着压力的升高而提高．随气体流量的变化，可将曲线划分为气体供应短缺、饱和和过量三个区域．同时按照电流密度计算所得到的气体消耗量可以在实验中得到很好地验证．实验结果对质子交换膜燃料电池结构的优化和设计具有重要的指导意义．     

海上风电机组用N38SH永磁体在盐雾中的性能

针对风电机组在生命周期内始终受到盐雾、湿热环境影响的问题,研究了发电机中永磁体在海洋盐雾环境下的性能变化.通过盐雾腐蚀试验,模拟发电机用N38SH永磁体的服役环境,研究其在盐雾腐蚀条件下磁性能的变化,为海上风电机组永磁体的保护提供理论依据.试验结果表明,无论有无镀层保护,盐雾腐蚀将极大程度影响永磁体的磁性能,特别是在剩余磁感应强度和矫顽力等性能指标下降较多时,需要专门的保护措施.     

Mold-filling ability of semisolid alloy

The mold-filling ability of the semisolid alloy has very important effects on the quality and properties of the work pieces produced by the semisolid forming process. The factorial experiments show that all of the heating factors, such as mold temperature, heating temperature and the keeping time of billets, have some effects on the mold-filling ability of semisolid alloy. According to the analysis of influencing extent on the filling ability, it is found that the most important one of the factors is the mold temperature instead of the billets temperature, the next one is the heating temperature of the billet, and the keeping time rows on the third. It is also found that there is an interrelation between the billet heating temperature and the mold temperature. The effect of the interrelation on the mold-filling ability is even stronger than the keeping time. The higher the mold temperature, heating temperature or the keeping time is, the better the mold-filling ability of the semisolid alloy is. The parameter to describe the mold-filling ability, defined as the maximum filling height alongthe upright direction or the maximum filling length along the horizontal direction, can be theoretically determined according to the flowing theory of viscous fuid.     

Microstructures and mechanical behavior of PM Ti-Mo alloy

1　INTRODUCTIONTitaniumalloyshavebecomewidelyusedbioma terialsforhigh loadimplants ,becauseoftheirgoodbiocompatibility ,excellentcorrosionresistance ,lowdensityandhighspecificstrength .Ti 6Al 4V ,withahighstrengthandagoodmachine ability ,hasbeenthemostsuccessfullyusedTialloyinclinicalapplica tion [1 5] .However ,recentlyscientistshavefoundthatAlandVelementsinthisalloywilldoharmtohumanorganisms ,andshouldbesubstitutedbyothermorehost friendlyelements ,forexample ,Nb ,Zr ,FeandMo[6 10 ] …     

铜薄膜作中间层的镁铝扩散焊接

采用磁控溅射技术在变形镁合金表面沉积铜薄膜,将其作为中间层对变形镁合金和硬铝合金进行了低温扩散焊接研究.利用超声波显微镜、X射线衍射、扫描电镜、电子探针等对焊接接头界面区域的显微结构及物相等进行了研究.研究结果表明,在镁合金基体上沉积的Cu薄膜主要以(111)、(200)晶向上生长,薄膜表面平整、均匀、致密;在扩散焊接工艺条件焊接温度T=455℃、保温时间t=90 min、压力P=3 MPa下获得了质量较好的Mg/Al焊接接头.焊接接头界面区域由铝镁原子比分别为3∶2,1∶1,12∶17三层镁铝系金属间化合物构成,接头断裂破坏发生在镁铝系化合物层,断口呈现明显的脆性断裂特征.     

The wettability of Fe based alloy on TiO

For developing TiO based imitated gold materials, the wettabilities of Fe and Fe-Cr-Ni-Ti on TiO were studied. The results indicated that the wettabilities of Fe and Fe-Cr on TiO were poor, and their wetting angles were about 90° at melting point. The wetting angles reduced with the increase of wetting temperature, but the influence of temperature was small. Fe and Fe-Cr containing Cr 50% or less could react with TiO on the interface to form Fe₂Ti and Ti₂O₃, but this did not improve the wettability effectively. When Ni-Ti was added into Fe-Cr alloy, Ni₃Ti was formed on the interface, which can reduce the interface energy, improve the wettability, and prevent the formation of Fe₂Ti and Ti₂O₃. The wetting angles could go down to about 40° when 3% Ni-Ti was added to Fe-Cr alloy. Biography of the first author: LI Qing-kui, Dr., senior engineer, born in August 1966, majoring in rare metal materials.     

Electroplating Zn—Al Alloy Technology

The method of controlling separating anode and separating power source was used to perform orthogonal optimization for the parameters in electroplating Zn-Al alloy,The electroplating Zn-Al alloy technology was decided,in which the content of Al is about 12%-15%.     

Effect of the addition of Al-Ti-C master alloy on the microstructure and microhardness of a cast Al-10Mg alloy

The microstructure and microhardness of a cast Al-10wt%Mg （henceforth Al-10Mg） alloy with 0.2wt% addition of Al- 5Ti-0.25C master alloy were compared with those of a refiner-free alloy of similar chemical composition. It was found that this level of the master alloy addition not only caused an effective grain refinement, but also caused a significant increase in the microhardness of the Al-10Mg alloy. Microchemical analysis revealed that TiC particles existed in the grain center. The relationship between the holding time and grain size was also studied. It shows that the grain refining efficiency is faded observably with the holding time. This is explained in terms of the instability of TiC particles.     

一种近α型钛合金的高温氧化行为

采用扫描电镜、X射线衍射仪等研究了近α型钛合金Ti230在1 000℃～1 300℃特高温氧化行为.研究结果表明,在高于1 000℃的特高温下其氧化动力学曲线呈抛物线-直线规律;在超过氧化产物CuO熔点（1 065℃）氧化时,氧化最外层仅为单一金红石型TiO2,此时氧化层中的CuO挥发,氧化增重有减小的趋势;随氧化温度升高,合金的抗氧化能力降低.Ti230合金经本试验温度氧化所形成的少量液相对Ti230合金的组织形态影响不显著.     

具有高强度和良好塑性的锆基晶态合金

在非晶材料家族中,锆基非晶以其强度高而成为最具应用前景的结构材料之一.但因其很难制备出大尺寸、很难加工成形及含有有毒的铍元素等原因,使其应用受到限制.Zr-Ti-Al-V系列晶态锆基合金,具有与锆基非晶的强度相当但塑性远远高于非晶态锆基合金的良好力学特性,其抗拉强度和延展性分别可以达到1720 MPa和3.3%.更为重要的是,锆基合金可批量生产、不含有毒的铍元素以及没有尺寸和形状的限制等非晶合金不具备的特性.