Preparation and performance of a cold gas dynamic sprayed high-aluminum bronze coating

By mixing preheated high-aluminum bronze powders with different amounts of Al_2O_3 powder, a low-pressure cold-sprayed coating was prepared and sprayed onto a Cr12MoV steel substrate. The hardness of the coating and the bonding strength between the coating and the substrate were tested with a HV-1000 microhardness tester and a mechanical universal testing machine. The surface microstructure, cross-section and tensile fracture surface of the coating were observed with a scanning electron microscope(SEM). Correspondingly, the influences of the preheat treatment temperature of the bronze powder and the Al_2O_3 content on the coating performance were investigated. The results indicate that the hardness of bronze powders decreased and the coating deposition rate increased after the preheating treatment of the bronze powder. The Al_2O_3 content in the mixed powders contributed to the deformation of bronze powders during the spraying process. This trend resulted in varied performance of the coating.

High temperature performance of arc-sprayed aluminum bronze coatings for steel

The high-temperature oxidation behavior of arc-sprayed aluminum bronze coatings on steel substrate was studied during isothermal exposures in air at 900 ℃. The surface morphologies and interface of the coatings after isothermal oxidation at 900 ℃ for different times were observed. The experiments showed that the coatings on steel substrate were not deteriorated and the substrate was protected well, being exposed to high temperatures up to 900 ℃ . The coatings withstood more than ten times thermal shock tests without any coating separation. The thermal expansion coefficient of the coatings was measured, revealing not much difference between it and that of steel substrate. After exposure at high temperature, the coatings were still adhered to steel substrate well. Isothermal mass gain of the coatings at elevated temperature in dry air was measured by means of a thermal balance and the oxidation behavior was evaluated by oxidation kinetic curves, exhibiting the oxidation kinetics curve accorded with a parabolic law. The parabolic rate constant of the oxidation kinetic curve is 1.02×10?9 g2·cm?4·s?1 for the first 60 min and from 150 min to 2 880 min the constant is 5.1×10?12 g2·cm?4·s?1.

A comparative investigation on wear behaviors of physical and chemical vapor deposited bronze coatings for hydraulic piston pump

The cylinder block/valve plate interface is one of the most critical frictional interfaces of the swashplate-type axial piston pump.However,the poor lubrication interface caused rapid wear and high friction loss in an elastohydrodynamic lubrication system,decreasing the pump lifetime.Wear resistant bronze coatings were fabricated on 38CrMoAl substrate by Physical Vapor Deposition(PVD)and Chemical Vapor Deposition(CVD),respectively.Ball-on-disc wear tests were performed to comparatively investigate the wear behaviors of the coatings and bulk ductile iron samples.It can be found that the PVD-bronze coating exhibited better wear resistance than the other two samples.This enhanced wear resistance was attributed to the unique composite microstructure and desired mechanical strength,which could resist to mechanical shear and spallation,decreasing friction loss.The appropriate hardness of(1.33±0.07)GPa could be beneficial for enhancing its wear resistance.The PVD-bronze coating possessed a much lower and stable coefficient of friction(about 0.1)and wear rate(about 6000μm3.N-1.m-1)under the loading forces of about 100 N after 20 min.The wear mechanism was the abrasive wear.

The microstructural evolution and wear properties of Ni60/high-aluminum bronze composite coatings with directional structure

The directional structure of Ni60/high-aluminum bronze composite coating was formed using induction remelting and forced cooling.The microstructural evolution and the characteristics of interface growth were studied.The results showed that the remelted coating formed metallurgical bonding with the substrate.The micros tructures changed from plane crystal to dendrite,cellular dendrite,fine cellular dendrite,and then to dendrite again with the increase in the cooling rate.The crystal grew along the heat flow direction and had(111) and(200)preferred orientations when the cooling rate was 1.886 ml-min^(-1).mm^(-2).The plane crystal,dendrite and cellular dendrite were mainly composed of compounds and solid solutions with Ni,Fe and Cu,and they were surrounded by strengthening phases composed of Cr,C and B.The grain boundary of directional structure coatings showed the characteristic of regular eutectic growth,but grain boundary of remelted coating presented characteristic of divorced eutectic growth.The wear resistance of directional structure coatings is better than that of remelted coating.

热/冷喷涂典型抗空蚀涂层结构与性能研究

冷喷涂作为近年来兴起的涂层固态沉积技术,所制备的涂层具有高结合强度、高硬度、无氧化夹杂等优点,在过流器械表面的空蚀损伤防护方面极具应用潜力。采用冷喷涂技术,在40Cr钢基体表面制备了高致密的CuAl9Fe1铝青铜抗空蚀涂层,利用光镜/扫描电镜、显微硬度计、超声波空蚀试验机、三维轮廓仪等设备,表征了涂层的微观结构、力学性能及抗空蚀性能,分析了涂层的空蚀破坏形貌及机理,并与超音速火焰(high-velocity oxygen-fuel,HVOF)喷涂制备的WC类典型抗空蚀涂层(WC-Co-Cr和WC-Cr_(2)C_(3)-Ni)进行了对比。结果表明,冷喷涂CuAl9Fe1涂层的平均孔隙率为1.4%,平均显微硬度为3126 MPa,平均结合强度为32.3 MPa,空蚀6 h的空蚀深度为4.988μm;与之相比,HVOF喷涂的WC-Co-Cr和WC-Cr_(2)C_(3)-Ni涂层的平均孔隙率分别为0.7%和1.6%,平均显微硬度分别为10 065和10 094 MPa,平均结合强度分别为84.2和73.5 MPa,空蚀6 h的空蚀深度分别为11.901和10.645μm。冷喷涂CuAl9Fe1涂层虽硬度较低,但塑韧性较好,可有效抑制空蚀过程中颗粒结合界面的裂纹萌生、扩展导致的颗粒脱落,因此相比HVOF制备的WC类涂层具有更高的抗空蚀性能。

纳米颗粒透明隔热涂料的制备与性能研究

采用羟基丙烯酸树脂与氨基树脂,外加纳米铯钨青铜(Cs_(x)WO_(3))、氧化锡锑(ATO)及助、溶剂制备了纳米颗粒透明隔热涂料。探究了丙烯酸树脂羟基含量、氨基树脂、流平剂及附着力促进剂对隔热涂层性能的影响。结果表明:羟基质量分数为1.7%~2.2%的丙烯酸树脂与高亚氨基高甲基化氨基树脂固化效果最佳,ATO/Cs_(x)WO_(3)按质量比1∶2添加可使涂层隔热透光效果兼优,聚醚改性有机硅流平剂可提升涂层耐划痕性且不影响漆膜外观,氨基硅烷类附着力促进剂可显著提升涂料热贮稳定性。

热喷涂铝青铜-聚苯酯涂层耐磨性能研究

本文采用大气等离子喷涂工艺在典型零件支承环上制备了铝青铜-聚苯酯耐磨涂层,测试了涂层硬度、结合强度、微观组织等性能,重点考核了在转速20000 r/min,输入扭矩800 N·m,滑油温度90~100℃,滑油压力0.2~0.3 MPa,运行时间50 h条件下的支撑环涂层整机台架试验后的耐磨性能;试验结果表明,制备的铝青铜-聚苯酯耐磨涂层硬度89.6 HR15Y,结合强度25.5 MPa,涂层组织均匀、孔隙率为15.18%,采用目视和体视显微镜检查台架试验后的典型件涂层外观状态,通过高精度三坐标测量方法计算涂层的磨损量,台架考核试验结果表明,典型件铝青铜-聚苯酯涂层完整、光滑,无开裂、剥离、剥落,涂层磨损最严重位置的磨损量为0.006 mm,涂层耐磨性能优异。

等离子制备高铝青铜合金粉体涂层的组织及其性能

为解决模具关键部位更换铝青铜垫块的加工、更换困难和铝青铜模具脆性大的问题,通过气体水雾化法制备Cu-14Al-X高铝青铜合金粉末,用等离子热喷涂制备涂层.用X射线衍射分析、往复式摩擦实验、扫描电镜、电子探针等方法研究Cu-14Al-X合金等离子涂层组织、结合强度和摩擦磨损性能.结果表明,涂层与基材为冶金结合,组织为β+γ+Κ,硬度达372 HV,试样在实际工况相当参数(压力15.6 MPa,滑动速度0.2 m/s)下与304不锈钢干摩擦对磨,摩擦系数为0.08.等离子涂层具有良好的减摩性和耐磨性,满足静态挤压模具工作要求.

新型铝青铜合金粉体材料涂层耐腐蚀性能研究

采用扫描电镜、能谱及静态浸泡腐蚀实验等方法研究了雾化法制备的新型铝铜合金粉末(Cu-14Al-X)通过等离子喷焊的方式作为涂层材料分别在3.5mol/L NaCl溶液、10mol/L HCl溶液、5mol/L H2SO4溶液中的腐蚀行为以及耐腐蚀性。结果表明,这种新型的涂层材料具有良好的耐腐蚀性能。涂层中的(α+γ2)共析体与β′相、α相和K相相比,具有优先腐蚀倾向,涂层发生的主要是脱铝腐蚀。在3种溶液环境下的腐蚀速率由小到大依次为:5mol/L H2SO4溶液,10mol/L HCl溶液,3.5mol/L NaCl溶液。

新型铝青铜及其喷涂层中Ce元素的作用(英文)

采用一次共装熔炼、砂型铸造Al含量超过Cu-Al二元合金共析点的新型铝青铜合金Cu-14Al-4.5Fe,在45#中碳钢表面制备铝青铜等离子喷涂层。通过扫面电镜、X射线衍射分析、电子探针、透射电镜和显微硬度计分析Ce元素对新型铝青铜合金及喷涂层表面组织形貌和维氏硬度的影响。结果表明:添加0.6%Ce到铸态合金及喷涂层可以使细化的κ相均匀分布于基体,并提高材料硬度。等离子喷涂层快速凝固,保留铝青铜涂层中Fe元素的过饱和固溶体,避免生成(α+γ2)共析相。含Ce喷涂层中的堆垛层错是提高材料力学性能的因素。

超音速火焰喷涂涂层的摩擦磨损性能研究

采用划痕分析和干砂粒/橡胶轮磨损测试,主要研究了超音速火焰喷涂(H igh-Veloc ity-A ir-Fuel,简称HVAF)WC涂层与A l-N i-Cu合金的摩擦磨损性能,并且与电镀硬铬的性能进行了对比。结果表明,HVAF WC涂层和A l-N i-Cu合金都发生微量磨损,而电镀铬层中发生明显的增重,同时导致A l-N i-Cu合金大量磨损。在与A l-N i-Cu合金对磨中,HVAF WC涂层的磨损机理为磨粒磨损,而电镀硬铬为粘着磨损。滚动接触疲劳磨损对涂层均有作用。

转移涂料法在青铜浮雕艺术铸造中的应用

介绍了一种制作青铜艺术品的新工艺。通过调整转移涂料的各种性能来满足青铜艺术铸品的各种要求 ,最终将转移涂料精密成形技术与青铜艺术铸造有机结合在一起 ,为艺术铸造开辟了新的途径。从涂料组成、喷涂工艺以及造型工艺等方面进行探讨 ,较好地解决了自硬转移涂料在青铜艺术铸造应用中的主要问题。

Ni60/高铝青铜多元多相复合涂层制备及其微观结构特征

为了研究Ni基/Cu基复合合金涂层的微观结构特征,采用超音速等离子喷涂技术在45#钢基体上制备了高铝青铜质量分数30%的镍基合金/高铝青铜多元多相复合涂层。对复合涂层的组织结构特征、元素分布、相结构组成以及涂层的微观缺陷进行研究分析。结果表明:所制备的复合涂层中2种合金微结构呈叠加层状分布,组织结构具有梯度复合涂层特征,致密度高,微界面结合良好。高铝青铜合金和Ni60合金元素呈交错分布,相互之间出现互扩散特点。高铝青铜合金具有对Ni基合金微粒包裹作用和对微界面填充作用,并且2种合金之间发生了冶金反应,微界面结合牢靠。相对于纯Ni60合金涂层,高铝青铜的加入有效降低了复合涂层缺陷率,减小了缺陷尺寸。

电弧喷涂铝青铜复合涂层的抗高温氧化作用与机理

采用铝青铜底层，外加厚度为0．1～0．2mm的纯铝涂层可进一步地提高涂层体系的抗氧化性能。900℃加热12h的10次循环氧化试验结果表明，纯铝层的应用有助于提高铝青铜涂层的自封孔能力，在涂层表面形成的增厚富铝氧化膜以及在涂层基体界面上形成的富铝氧化层都对钢铁基体的防护有利。复合涂层体系与试件基体结合可靠，没有早期失效迹象，是一种有希望的高温防护涂层体系。

电磁屏蔽导电涂料用片状镀银铜粉的研究

介绍了电磁屏蔽导电涂料用镀银铜粉的生产方法,对其性能指标进行测试。同时,将本研究制得镀银铜 粉应用于导电涂料的配制,制得电磁屏蔽导电涂料,并对导电涂料性能指标进行测试。并对行业的发展进行了展望。

环氧-聚氨酯互穿聚合物网络导电涂料

研究了以环氧－聚氨酯互穿聚合物网络（ＥＰ－ＰＵＩＰＮ）为基料，镀银铜粉为导电填料的导电涂料。用扫描式电子显微镜（ＳＥＭ）观察了不同配比ＥＰ－ＰＵＩＰＮ的两相相容性，用差示扫描量热法（ＤＳＣ）测定了ＩＰＮ的玻璃化温度。讨论了ＥＰ－ＰＵＩＰＮ的结构及选择，镀银铜粉的粒度及含量对导电涂料的电阻率和使用性能的影响。试验表明，９０／１０ＥＰ－ＰＵＩＰＮ作为基料，镀银铜粉的含量为８０％、粒度为４００目，涂膜的电阻率低，使用性能好。

苯并三唑的用量对青铜文物封护剂耐蚀性能的影响

采用缓蚀剂苯并三唑 (BTA)等对丙烯酸酯聚合物乳液进行改性 ,研制成青铜文物防蚀封护剂。采用浸泡试验 ,盐雾试验 ,原子吸收分光光度法等试验方法 ,研究BTA用量对封护剂耐蚀性能的影响。结果表明 ,BTA对防蚀封护剂的耐酸性、耐碱性、耐盐水性、耐水性。

铝合金表面激光熔覆 Fe- Al青铜合金层的组织结构

研究了铝合金表面激光熔覆 Ｆｅ Ａｌ青铜层的组织结构， 结果表明， 熔覆层的组织结构为孪晶结构的 α Ｃｕ＋ 颗粒状（ Ｃｕ， Ｆｅ， Ｓｉ）９ Ａｌ４ （γ１ ）＋ 少量的 Ｃｕ３ Ａｌ（β）， 硬质点相强化、孪晶强化、细晶强化和固溶强化的共同作用使得熔覆层的维氏硬度达到了 ３ ０００ Ｍ Ｐａ～３ ５００ Ｍ Ｐａ， 明显高于其名义硬度 １ ８００ Ｍ Ｐａ～２ １００ Ｍ Ｐａ。同时， 分析了熔覆层相结构的形成原因。

古铜色珠光颜料的制备及动力学研究

以云母钛为基材 ,用Fe2 O3对其表面进行包覆 ,从而制得古铜色珠光颜料。研究了包覆过程和焙烧过程的最佳工艺参数 ,以及通过热重分析研究了前驱体热分解过程的反应动力学 。

丙烷压力对超声速微粒沉积铝青铜涂层组织和性能的影响

采用超声速微粒沉积技术在不同丙烷压力(0.469 MPa,0.496 MPa,0.524 MPa,0.551 MPa)条件下制备4种铝青铜涂层,采用环境扫描电子显微镜、X射线衍射仪、能谱仪等试验仪器表征涂层的微观组织、相结构以及氧元素质量分数等,运用显微硬度仪、拉伸试验机和CETR摩擦磨损试验机等试验设备分析涂层的力学性能和摩擦学性能。结果表明,丙烷压力对涂层组织结构及力学性能有显著的影响,随着丙烷压力的升高,涂层孔隙率与氧元素质量分数呈负相关关系,在丙烷压力为0.524 MPa时,涂层孔隙率为0.8%,氧元素质量分数为0.97%,更接近其平衡点;丙烷压力为0.524 MPa以下时,涂层较原始粉末物相无明显变化,主要仍为α+β'+K相;涂层显微硬度、结合强度及耐磨性能随丙烷压力的升高均呈先增大后减小的趋势变化,丙烷压力为0.524 MPa时,涂层的力学性能和耐磨性能达到最优。