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 15 毫秒
1.
Micron grade Sn powder, VG32 oil and active pharmaceutical were mixed and the Nanometer Sn lubricant additives were prepared. Nanometer additives with different Sn concentrations were used in Steel-brass Tribo-pair for friction and wear test. The activating method to nano-Sn and surface of brass samples was investigated, and the method to form relatively thick friction coating on samples was discussed. Surface elemental distribution, coating thickness and its surface appearance were analyzed with X-ray photoelectron spectrum (XPS), auger electron spectrum (AES) and scanning electron microscope (SEM) respectively. The result shows that the ultra-thick friction coating (approx 20 μm), with abundant tin and well combined with substrate, has formed on the brass sample. The friction coating revealed superior performance of friction reducing and anti-wear properties. Therefore, the results possess practical significance to self-repair usage on steel-brass tribo-pair in mechanical systems.  相似文献   

2.
结合溶胶-凝胶法和化学镀方法,于镁合金基材表面成功制备了均匀的复合Ni-P-SiO_2/TiO_2/Al_2O_3镀层,采用扫描电镜(SEM)、光学显微镜(OM)、摩擦磨损试验及电化学方法,对比研究了Mg基材、基础Ni-P镀层与3种复合镀层的显微组织结构、耐磨性及耐腐蚀性。结果表明,加入3种溶胶所制备的复合镀层较Mg基材大幅度提高耐磨性和耐腐蚀性;3种复合镀层较Ni-P镀层具有更加均匀、致密的显微形貌,减少了直接加入纳米粉末的团聚,同时耐磨和耐蚀性改善。其中Ni-P-SiO_2复合镀层具有较高的显微硬度(HV513)和最低的摩擦系数(0.34),最高的腐蚀电位(-1.18V)及较小的腐蚀电流密度(9.5×10~(-3)mA·cm~(-2))。综合制备最佳工艺,并考虑节能减排因素,Ni-P-SiO_2复合镀层可作为性能优良的Mg合金耐磨、耐腐蚀镀层使用,于实际工业生产大有裨益。  相似文献   

3.
INTRODUCTION Polycrystalline diamond compacts (PDC), con-sisting of a polycrystalline diamond (PCD) layer on a WC-Co substrate, and having high hardness and abrasive resistance, are used in a variety of drilling and machining applications (Farhad, 2001; Sadi and Muzaffer, 2001). However, due to differences of thermal and mechanical properties in diamond and WC-Co substrate, residual thermal stresses develop in regions near the interfaces during fabrication. The diamond coating exhib…  相似文献   

4.
微量调速系统的摩擦特性是影响低速稳定性的主要原因之一,目前人们在10mm/min速度下,对单一类型的液压缸密封装置、导轨与滑台摩擦特性已有了较深的认识,但还未对该系统在5mm/min的速度下进行摩擦特性的研究。本文对此条件下该系统低速磨擦特性进行了研究分析。  相似文献   

5.
采用正交试验法研究板材变形程度、润滑条件、轴向加裁力大小和变形速度对AZ31B镁合金挤压板材室温拉楔性能的影响,结果表明:变形程度对拉楔试验顺利完成的影响最为显著,其次是润滑条件和轴向加载力大小,采用固体润滑剂的润滑效果优于油脂类润滑剂,且轴向加载力越大对拉楔试验成功越有利;而变形速度超过1 mm/min时,其影响效果不明显.在拉楔系数0.883,轴向加载力为拉楔力的1.759倍,使用固体肥皂作为润滑刑,取得了良好试验效果.  相似文献   

6.
Aiming at the surface integrity of titanium alloy Ti-6Al-4V in high speed side milling, a series of side mill- ing tests were carried out with uncoated carbide milling cutter at various milling speeds. Surface roughness, residual stress, subsurface microstructure and microhardness variations were investigated. The surface roughness measurement results present that the milling speed from 80 to 120 m/min fails to produce better and more stable roughness values compared with the result obtained from 320 to 380 m/min. The residual stresses in the feed direction and axial depth of cut direction are in similar trends for the two milling speed levels mentioned above. Moreover, the residual stress pro- duced at 320 to 380 m/min is lower and more stable than that at 80 to 120 m/min. The microstructure analysis shows that the volume of β phase in the near surface becomes smaller and the deformation of β phase in the near surface be- comes obvious with the increase of the milling speed. Subsurface microhardness variation was observed down to 200 μm below the machined surface at 80 to 120 m/min and down to 160 μm at 320 to 380 m/min. It is concluded that better surface integrity and higher material removal rate can be obtained at 320 to 380 m/min than at 80 to 120 m/min.  相似文献   

7.
唐威 《唐山学院学报》2021,34(3):10-14,28
采用激光填丝焊对Al-Li-Er铝合金进行焊接处理,研究激光功率、焊接速度和送丝速度对焊接接头显微组织与力学性能的影响。结果表明,当送丝速度为3 m/min和4 m/min时,Al-Li-Er合金焊接接头的焊缝面积都会随着激光功率和焊接速度的增大而逐渐减小;在相同激光功率和焊接速度时,送丝速度的增加会增大焊缝面积,且随着送丝速度的增加,激光焊接接头的上余高系数和下余高系数都呈现逐渐增加的趋势。Al-Li-Er合金适宜的激光焊接工艺参数为激光功率3 kW、焊接速度3 m/min、送丝速度2~3 m/min,此时焊接接头的室温拉伸性能与母材较为接近。  相似文献   

8.
利用反应等离子熔覆技术、以Fe-Cr-C-W-Ni合金粉末为原料,在Q235钢表面制得了Cr7C3高铬铁基金属陶瓷增强耐磨复合涂层。利用SEM、EDS和X射线衍射分析了涂层的显微组织,在室温干滑动磨损试验条件下测试了涂层的耐磨性。结果表明:反应等离子熔覆Cr7C3高铬铁基金属陶瓷增强耐磨复合涂层硬度高、组织均匀、与基材之间为完全冶金结合;涂层在室温干滑动磨损试验条件下表现出优异的耐磨性,涂层磨损的质量损失随载荷增加十分缓慢,涂层具有优异的载荷特性。  相似文献   

9.
文章探讨了氨酚氯雷伪麻缓释片的薄膜包衣工艺。目的:研究氨酚氯雷伪麻缓释片薄膜包衣的一次性合格率。方法:采用正交实验确定薄膜包衣的工艺参数,选择最佳工艺。结果:确定了薄膜包衣的最优工艺参数:包衣的欧巴代用量为5%,喷量400g/min,转速15 r/min。结论:按照此工艺生产的氨酚氯雷伪麻缓释片达到质量标准,稳定可靠。  相似文献   

10.
采用包渗法在钼表面原位制备了(Mo,W)Si2-Si3N4复合涂层,考察了其在大气中于500℃和600℃等温循环的氧化性能,利用XRD和SEM等研究了其组织形貌.结果表明:(Mo,W) Si2-Si3N4涂层具有良好的低温抗氧化性,其在空气中500℃和600℃氧化480 h的氧化速率分别为0.0145 g/(m2·h)和0.0191g/ (m2·h),归因于涂层氧化表面形成了致密的SiO2膜.  相似文献   

11.
A micro turbo-expander capable of high working speed was specially manufactured for use in an organic Rankine cycle (ORC). A series of tests were executed to examine the performance of the machine. In the experiment, the machine was tested under different inlet pressure conditions (0.2–0.5 MPa). Data such as the compressed air pressure, temperatures of the inlet and the outlet, rotational speed, and electric power generation were analyzed to discover underlying relationships. During the test, the rotational speed of the machine reached as high as 54 000 r/min, the peak value of the temperature drop between the inlet and the outlet reached 42 °C, the maximum electric power generated by the motor-generator attached to the machine reached 630 W, and the efficiency of the machine reached 0.43.  相似文献   

12.
用高能球磨制备等原子比铁(Fe)钴(Co)镍(Ni)铁镍钴复合粉体,用激光熔覆方法制备复合粉铁镍钴体合金涂层。用OM、HV、XRD、SEM、EDS、SVET等对复合粉体及熔覆合金层进行了组织表征及性能测试。结果表明,复合粉体经3 h高能球磨后均匀细化,平均尺寸从35μm到15μm左右,镍晶格有一定畸变,有新相Co3Fe7产生;用优化后的激光熔覆工艺激光功率2000 W,激光扫描速度10 mm/s,保护Ar气流速度12 L/min制备中熵熔覆合金FeCoNi涂层;XRD、SEM、EDS表明熔覆层合金是单一的面心立方(FCC)相,Fe,Co,Ni成分均匀分布,没有金属间化合物产生;熔覆层的HV约是243,在0.5 mol/L氯化钠溶液中熔覆层的SVET表明耐腐蚀性能好。  相似文献   

13.
建立了杂物在静电场中的运动轨迹模型,运用多物理场耦合模型对静电辊表面的电场分布、杂物在电场中的运动轨迹进行仿真分析;采用单因素实验法研究各种摩擦式静电除杂样机除杂率的影响。结果表明:试验效果与仿真结果的趋势基本一致,在环境湿度为60%RH、静电辊转速为25 r/min时,杂物的挑出率为98.77%,相较于最初的工艺参数平均挑出率提高了20.51%。研究为提高摩擦式静电除杂机的除杂率提供参考。  相似文献   

14.
研究用于Ni-P/Al2O3化学复合镀液的Al2O3悬浮液分散剂.将140 nm的α-Al2O3干粉与表面活性剂溶液混合,采用高速机械搅拌和超声波分散Al2O3悬浮液.通过分光光度计测定悬浮液吸光度,用PdCl2测试镀液稳定性;通过孔隙率试验和结合力试验测试化学复合镀层性能,用SEM和EDS测试镀层形貌和化学成分.试验结果表明,阴离子型表面活性剂与非离子型表面活性剂复配,对Al2O3悬浮液的分散稳定有较好的协同效果,适宜的复配分散剂组成为:20 mg/L十二烷基硫酸钠,150 mg/L Tween-80,80 mg/L聚乙二醇.用其配置2 g/L纳米Al2O3悬浮液,静置24 h后吸光度为1.595.该悬浮液配置的镀液稳定性试验时间为165 s,镀速为16.5μm/h.复合镀层中Al2O3粒子呈弥散状分布,Al2O3含量为0.77%.镀层光亮、致密.孔隙率为0.06个/cm2.结合力符合GB/T13913-92标准.该复配分散剂适应于Ni-P/Al2O3化学复合镀液.  相似文献   

15.
Carbon fiber reinforced copper matrix composite is anewtype of material that can be used in an unlubricatedfriction pair because it has a good self-lubricating perfor-mance in dry sliding against the steel[1 ,2].The wear char-acteristics of composites int…  相似文献   

16.
由于静摩擦力和滑动摩擦力在概念、存在条件和作用效果等方面都很相似,所以。通常人们都忽略了它们之间的差别,认为静摩擦力和滑动摩擦力是同一类力,把它们都归属为摩擦力,而实际上静摩擦力和滑动摩擦力是性质完全不同的两类力。本文从力学的基本原理出发,通过对静摩擦力和滑动摩擦力做功过程的理论分析和计算,给出静摩擦力和滑动摩擦力做功特点及做功过程能量转换差异,从而得出结论:静摩擦力和滑动摩擦力是两类性质不同的力,即静摩擦力是一种非耗散力而滑动摩擦力是一种耗散力。  相似文献   

17.
INTRODUCTIONTensionedmembranestructuresaremostsuitableforuseasroofstructureforavarietyofbuildingtypes,astheyprovidealight,elegant,andefficientstructurespanningoveralargeclearspace (Otto,1 973 ) .Examplesincludegymnasi ums,exhibitioncenters ,concertpavilio…  相似文献   

18.
采用正交试验法,选用L934正交表,以氦检漏泄漏率作为考核指标,对影响焊接效果的电压、脉宽、离焦量和转速四个因素进行试验研究,最终优选的工艺参数组合为A3B2C1D2,即电压为36档,脉宽为3.5ms,离焦量为+1.0mm,转速为3/7r/min。此方法对其它工艺参数的优化研究具有指导和推广意义。  相似文献   

19.
开发了1种用于钢铁表面涂装前处理的常温清洁锌钙系磷化液。该磷化液不含亚硝酸盐和重金属,在10~35℃下浸渍磷化5~10 min,1 m2即可生成质量约为2 g的浅灰色、均匀、致密的磷化膜,耐CuSO4溶液点滴时间达90~120 s,耐3%氯化钠溶液浸泡时间为230 min。  相似文献   

20.
为降低路面和冰雪之间的黏结力,用有机硅憎水材料作为道路表面涂层.有机硅憎水涂层技术的除冰效果用接触角实验和剪切实验来表征,其耐久性用加速加载磨耗实验来评价,而其抗滑性能则用摆式摩擦法和铺砂法来评价.接触角实验结果表明,有机硅憎水涂层材料与水的接触角为100.2°,具有很好的憎水性能.其次,通过剪切实验可以得出:在涂有有机硅憎水材料的情况下,冰层与试件表面的最大剪切应力仅为0.06 MPa,低于没有进行表面涂层处理的最大剪切力3.5 MPa;剪切之后,冰层能够很完整地从试件表面脱落.加速加载磨耗实验表明,在经过一定时间的磨耗之后,残留在沥青路面构造深度里的有机硅涂层材料仍然具有除冰雪的效果.表面涂层后的道路表面的BPN值和构造深度值均有所降低,但是其仍然远远大于规范的要求,确保了安全性.研究表明,沥青道路表面涂层技术能有效地降低沥青路面与冰层的黏结,从而解决冬季道路结冰影响行车安全的问题.  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