高速电弧喷涂锌涂层性能研究

使用高速电弧喷涂枪和普通电弧喷涂枪分别制备锌涂层。通过对结合强度、孔隙率、粒子尺寸和粒子飞行速度的测试表明,高速电弧喷涂比普通电弧喷涂的粒子尺寸减小,飞行速度提高,制备的锌涂层结合强度高,孔隙率低。对两种锌涂层进行的强化腐蚀试验表明,封孔处理后的高速喷涂锌涂层具有较好的抗腐蚀性能。     

Al及Al-Re高速电弧喷涂层性能的研究

对高速电弧喷涂(HVAS)与普通电弧喷涂铝及铝稀土涂层进行了对比实验研究.结果表明,稀土元素的加入明显改善了涂层与基体的结合性能,降低了铝合金涂层的孔隙率,同时,铝合金涂层的孔隙率也受铝稀土丝材加工工艺的影响;高速电弧喷涂铝稀土材料时,涂层具有结合强度高、硬度高、孔隙率低、组织致密等特点.     

金属喷涂、堆焊与修复

金属喷涂工艺与设备 冷喷涂Au纳米粒子在金属表面沉积过程的分子动力学模拟；降低热喷涂涂层孔隙率的方法；电弧喷涂铝基涂层耐腐蚀性能；电弧喷涂技术在转炉烟罩水冷壁防护上的应用；制备低孔隙超细涂层的高速电弧喷涂枪……     

高速火焰电弧复合喷涂枪制备3Cr13涂层的性能

高速火焰电弧(HVAF-ARC)复合喷涂枪是高速火焰喷涂枪和电弧喷涂枪的结合体,利用产生的高速燃气来雾化加速电弧喷涂过程中产生的熔融粒子,提高了喷涂粒子的飞行速度,降低了粒子的氧化,可高效制备优质的涂层。文中利用自主开发的新型高速火焰电弧复合喷涂枪和普通高速电弧喷涂枪,分别在钢基体上制备了3Cr13涂层,通过对涂层的性能检测发现,复合喷涂枪所制备涂层的氧元素含量和孔隙率都比普通高速电弧喷涂枪制备的涂层低,分别降低了33%和49%,硬度提高了12%,复合喷涂枪制备涂层的性能得到较大的提高。     

高速电弧喷涂镍铝打底层结构与性能研究

高速电弧喷涂技术是近年来发展起来的新型热喷涂技术，该技术具有优势，高效，低成本等特点，本文实验研究了高速电弧喷涂镍铝打底涂层的组织结构和力学性能，涂层的界面结合强度大于40MPa，显微硬度平均值为210HV，表面粗糙度表征参数Ra值为13．11um，涂层孔隙率为2．26％，涂层主要由镍铝合金和镍，铝氧化物组成，高速电弧喷涂镍铝涂层结合强度高，涂层组织致密，是优良的打底涂层。     

金属喷涂、堆焊与修复——金属喷涂工艺与设备

再制造电弧喷涂成形层的残余应力分析;铝合金表面电弧喷涂铝涂层工艺与性能;碳钢热喷涂渗铝互扩散系数计算;电弧喷涂法制备高耐蚀合金涂层及其性能研究;高速电弧喷涂硼化物金属复合陶瓷工艺参数优化试验研究     

大功率高速电弧喷涂层性能及其应用

采用新型大功率高速电弧喷涂系统,对比高速与普通喷涂枪的粒子雾化效果,分析了雾化粒子初速度对涂层结构的影响,对比了涂层表面粗糙度、孔隙率以及结合强度的差异。概述了近3年来大功率高速电弧喷涂系统的最新应用实例。     

电弧喷涂制备Al-Al2O3耐磨防滑涂层工艺优化和摩擦学性能研究

介绍了一种φ3mm铝基陶瓷复合材料粉芯丝材，用于高速电弧喷涂制备耐磨防滑涂层。以涂层的耐磨性为判据，采用正交试验对喷涂工艺参数进行了优化，并采用优化参数制备耐磨防滑涂层，与普通铝涂层的摩擦学性能进行对比，结果表明制备的耐磨防滑涂层摩擦因数高，防滑性能良好，弥散分布的A12OO3粒子提高了涂层的摩擦因数保持能力。     

电弧喷涂防腐蚀涂层研究

介绍了电孤喷涂稀土铝、铝合金涂层抗腐蚀性能试验,高速电弧喷涂锌、铝涂层的防腐蚀性能试验结果.指出喷涂材料和喷涂设备的发展情况,提高了涂层的防腐蚀性能,使电弧喷涂能够在防腐蚀领域得到更广泛的应用.     

高速电弧喷涂涂层的性能

分析了高速电弧涂层的结合强度、涂层显微硬度以及涂层孔隙率，并与普通电弧喷涂涂层对比，证明喷涂粒子飞行速度的提高，极大提高了涂层性能。     

新型高速电弧喷涂枪的开发研究

详细介绍了开发研制的新型高速电弧喷涂枪：分析测定了新型喷枪和普通喷枪出口的雾化气流速度,同时采用A1和3Cr13作为对比试验材料,对涂层进行性能研究并观察了其组织结构。结果表明：新型喷枪的雾化气流速度的捌试计算值在距枪口80mm的范围内仍然能保持在600m／s左右,比普通喷枪的雾化气流速度有显著地提高：高速电弧喷滁熔融的金属粒子雾化充分,涂层组织致密,层状结构十分明显,并且结合强度值和硬度值均较高：新型高速电弧喷涂枪,结构简单,工作性能稳定。高速电弧喷涂是一种优质、高效、低成本的热喷涂方法。     

Influence of the spray velocity on arc-sprayed coating structures

Thermal spray processes such as plasma spraying and HVOF have gained markets due to a steady process of development of materials and equipment. One disadvantage of thermal spray processes is that costs must be competitive compared to techniques such as PTA and electroplating. In order to reduce costs, the more economical spray processes like conventional wire flame spraying, as well as arc spraying, are becoming more popular. There are modern arc spray gun designs on the market that meet the requirements of modern coating properties, for example aviation overhaul applications as well as the processing of cored wires. Nevertheless, the physical basis of arc spraying is well known. The aim of the present investigation is to show how the influence of spray velocity (not particle velocity) affects coating structure with respect to arc spray parameters.     

工艺参数对高速电弧喷涂Al/1Cr13复合涂层组织结构的影响

用高速电弧喷涂制备Al/1Cr13复合涂层,采用3因素3水平正交试验法系统研究了电弧电流、电弧电压和喷涂距离对复合涂层的组织结构、孔隙率和氧含量的影响规律。采用扫描电镜对复合涂层的显微组织和孔隙率进行表征,采用氧氮含量分析仪测得涂层的氧含量。结果表明,在第9组喷涂参数即电弧电流为240A,电压为32V,喷涂距离为150mm的条件下制备的高速电弧喷涂Al/1Cr13复合涂层组织较致密,Al和1Cr13涂层的孔隙率最低分别为1.6%和2.2%。Al涂层氧含量显著低于1Cr13涂层,最低约为2%。     

高速电弧喷涂复合材料涂层工艺优化与性能研究

采用FeCrNi粉芯丝材利用正交回归试验研究了高速电弧喷涂工艺参数对FeCrNi/Al2O3涂层的力学性能影响规律，并优化工艺参数。结果表明，和其它工艺参数相比，喷涂距离对涂层的结合强度、硬质相沉积效率、显微硬度有显著影响，喷涂距离与喷涂压力的交互作用对显微硬度有较明显的影响。当喷涂电流为100A，喷涂压力为0．65MPa，喷涂距离为250mm时，FeCrNi粉芯丝材涂层的结合强度仍高达31．2MPa。     

高速电弧喷涂枪结构优化的试验

试验优化了一种高速电弧喷涂枪的结构.用SprayWatch-2i热喷涂监测系统测试了喷枪的雾化熔滴速度,并研究了Al涂层和3Cr13涂层的组织和性能.结果表明,丝材和导电嘴的存在,严重扰动了雾化气流流态,两丝夹角和丝交点离喷管出口距离也显著影响了喷管气流场的分布特征;改进设计喷枪的雾化熔滴速度显著提高,其3Cr13雾化熔滴的最高速度达到210 m/s;涂层组织和力学性能也得到改善,喷涂Al涂层和3Cr13涂层时,结合强度分别提高了55%和39%,硬度值也分别增加了26%和9%,涂层的显微组织更均匀致密,孔隙率更低.     

Mathematical modelling of Inconel 718 particles in HVOF thermal spraying

High velocity oxygen fuel (HVOF) thermal spray technology is able to produce very dense coating without over-heating powder particles. The quality of coating is directly related to the particle parameters such as velocity, temperature and state of melting or solidification. In order to obtain this particle data, mathematical models are developed to predict particle dynamic behaviour in a liquid fuelled high velocity oxy-fuel thermal spray gun. The particle transport equations are solved in a Lagrangian manner and coupled with the three-dimensional, chemically reacting, turbulent gas flow. The melting and solidification within particles as a result of heat exchange with the surrounding gas flow is solved numerically. The in-flight particle characteristics of Inconel 718 are studied and the effects of injection parameters on particle behavior are examined. The computational results show that the particles smaller than 10 μm undergo melting and solidification prior to impact while the particle larger than 20 μm never reach liquid state during the process.     

Particle Acceleration in a High Enthalpy Nozzle Flow with a Modified Detonation Gun

The quality of thermal sprayed coatings depends on many factors which have been investigated and are still in scientific focus. Mostly, the coating material is inserted into the spray device as solid powder. The particle condition during the spray process has a strong effect on coating quality. In some cases, higher particle impact energy leads to improved coating quality. Therefore, a computer-controlled detonation gun based spraying device has been designed and tested to obtain particle velocities over 1200 m/s. The device is able to be operated in two modes based on different flow-physical principles. In one mode, the device functions like a conventional detonation gun in which the powder is accelerated in a blast wave. In the other mode, an extension with a nozzle transforms the detonation gun process into an intermittent shock tunnel process in which the particles are accelerated in a high enthalpy nozzle flow with high reservoir conditions. Presented are experimental results of the operation with nozzle in which the device generates very high particle velocities up to a frequency of 5 Hz. A variable particle injection system allows injection of the powder at any point along the nozzle axis to control particle temperature and velocity. A hydrogen/oxygen mixture is used in the experiments. Operation performance and nozzle outflow are characterized by time resolved pressure measurements. The particle conditions inside the nozzle and in the nozzle exit plane are calculated with a quasi-one-dimensional WENO-code of high order. For the experiments, particle velocity is obtained by particle image velocimetry, and particle concentration is qualitatively determined by a laser extinction method. The powders used are WC-Co(88/12), NiCr(80/20), Al₂O₃, and Cu. Different substrate/powder combinations for varying particle injection positions have been investigated by light microscopy and measurements of microhardness.