首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 78 毫秒
1.
中温碱性化学镀镍磷实用新工艺研究   总被引:4,自引:1,他引:4  
用正交试验设计法和中心组合规则研究了以硫酸镍、次亚磷酸钠为主盐的化学镀液优 化配方,通过SAS8.2进行模拟得到二次多项式回归方程数学模型。研究了镀液中微量光亮 剂对镀速的影响。结果表明:在施镀温度为62.7℃,pH值为8.0,装载量为1 dm2/L,NiSO4· 6H20 36.03 g/L,NH4Ac 36.96 g/L,NaF 6.3 g/L,Na3C6H5O7·2H2O 23.52 g/L,NaH2PO2 42.4 g/L条件下,施镀1h,所得到的平均镀速为14.65μm/h,且镀层光亮,镀层含磷量为 7.8%~8.2%,镀层硬度为HV457,镀液可循环利用7个周期,能满足生产的实际需要。  相似文献   

2.
研究了全光亮化学镀镍层的主要技术条件,光亮剂的选择,被镀件表面状态对镀层光亮度的影响,合理施镀工艺条件。结果表明:该工艺可获得全光亮镀层,孔隙率低,耐蚀性能好。同时,对镀液的沉积速度、稳定性、装载量、pH值及施镀温度对镀层光亮度的影响均进行了试验。完成TL-013、TL-014两种全光亮化学镀镍磷合金浓缩液配方和完善的施镀工艺。  相似文献   

3.
为了防止黑色金属零件的锈蚀,经常采用电镀一层金属或发蓝来进行表面处理。常用的电镀方法有镀锌、镀镉和镀铬。表面处理后,可以提高零件的使用寿命并使外形美观。 图1是我厂生产的耳片的产品图样,它的2×φ6H11(07500.+)mm是要求镀后达到的尺寸。该零件的表面处理为镀锌,镀层厚度为5~12μm。要达到镀后φ6H11 mm的要求,就必须预留出镀层厚度,这样在镀后才可达到图样的尺寸要求。按照图样的最大极限尺寸镀最薄的镀层厚度、最小极限尺寸镀最厚的镀层厚度的原则,这个零件两孔的镀前尺寸应为: 最大极限尺寸=6.075+0.005×2=6.085 mm…  相似文献   

4.
针对兵器某飞行智能产品中所用高强度钢滑动零件化学镀镍磷合金难施镀及镀层性能差的特点,从材料特性与化学动力学的相互关系出发,运用正交试验和均匀试验,获得了适合于高强度钢的中温化学镀镍磷合金工艺技术,并顺应“清洁生产”的发展趋势。通过研究镀液主盐含量及比值、络合剂、加速剂、稳定剂、温度、pH值等因素对沉积速度、镀层耐蚀性与耐磨性的影响,解决高强度钢零件化学镀镍磷合金难施镀、镀层易起皮、结合力差、镀层耐蚀性与耐磨性匹配性差等问题。靶试及库存结果表明:该工艺技术获得的镀层性能良好,耐蚀性与耐磨性实现了最佳匹配,可为兵器装备高硬材料化学镀提供技术参考,尤其在复杂多变的环境下服役的智能化产品滑动零部件上,具有广阔的应用前景。  相似文献   

5.
Ni-P-Al_2O_3双层化学复合镀的工艺及性能   总被引:3,自引:0,他引:3  
】介绍了在钢铁表面施镀Ni-P-Al2O3化学复合镀前先进行Ni-P化学镀的工艺及施镀后的双层化学镀层的组织与性能。结果表明,双层复合镀层比单层复合镀层具有更好的结合强度和耐磨性,耐蚀性也得到改善  相似文献   

6.
Ni—P—Al2O3层化学复合镀的工艺及性能   总被引:2,自引:0,他引:2  
介绍了在钢铁表面施镀Ni-P-Al2O3化学复合镀前先进行Ni-P化学镀的工艺及施镀后的以化学镀层的组织与性能。结果表明,双层复合镀层比单层复合镀层具有更好的结合强度和耐磨性,耐蚀性也得到改善。  相似文献   

7.
镁合金表面化学镀镍-磷合金稳定剂的选用   总被引:1,自引:0,他引:1  
研究了KI、KIO3、PbAc2、KIO3+PbAc2和KIO3+硫脲五种稳定剂对镁合金表面化学镀镍-磷合金镀液的稳定性、镀层的表面形貌及性能的影响,并优选出适合于镁合金表面化学镀镍、磷合金镀层的最佳稳定剂。结果表明:随着稳定剂的加入,镀液的稳定性得到了改善,但不同种类稳定剂对镀液的稳定效果不同;二元复合稳定剂所得镀层的表面形貌、质量优于单一稳定剂的;根据镀层的性能,确定出KIO3+硫脲稳定剂是本试验条件下的最佳稳定剂。  相似文献   

8.
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…  相似文献   

9.
金刚石颗粒表面化学镀镍及其在树脂磨具中的应用   总被引:6,自引:1,他引:6  
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。  相似文献   

10.
Ni-P-CaF2化学复合镀层的制备及自润滑性能研究   总被引:1,自引:1,他引:0  
制备了以45#钢为基体的Ni-P-CaF2化学复合镀层并研究了该镀层的制备工艺;介绍了CaF2固体自润滑微粒镀前预处理技术,对镀层的表面形貌、结构、孔隙率等性能进行了分析;对复合镀层的自润滑性能进行了测定.研究表明:提出的所述复合镀层的工艺配方能够较好地完成复合镀层的施镀,得到非晶态的镀层;阴离子表面活性剂加非离子表面活性剂能够使微粒更好地分散在镀液中;常温下,Ni-P-CaF2复合镀层的自润滑性能较差.  相似文献   

11.
An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...  相似文献   

12.
The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.  相似文献   

13.
Giannuzzi LA  Utlaut M 《Ultramicroscopy》2011,111(11):1564-1573
30 keV Ga+ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z2, and shows a non-monotonic relationship between contrast and Z2. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z2, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.  相似文献   

14.
This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...  相似文献   

15.
分布动态载荷识别的抗噪处理   总被引:2,自引:2,他引:0  
针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.  相似文献   

16.
针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。  相似文献   

17.
The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...  相似文献   

18.
The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....  相似文献   

19.
Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.  相似文献   

20.
A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号