超音速火焰喷涂铁基非晶涂层热应力数值模拟

发布时间：2018-01-06 01:13

本文关键词：超音速火焰喷涂铁基非晶涂层热应力数值模拟　出处：《南昌航空大学》2015年硕士论文　论文类型：学位论文

【摘要】：本文以Kermetico公司的AK-07型喷涂系统喷涂Fe41Co7Mo14C15B6Y2非晶合金涂层为参考,在ANSYS软件平台上,使用ICEM软件对超音速火焰喷涂流体计算区域划分网格,采用FLUENT计算流体力学软件对超音速火焰喷涂过程进行三维数值模拟。通过提取流场分析的基体表面换热系数及近壁面温度参数,采用ANSYS软件的参数化编程语言编写有限元计算程序,建立了基于生死单元技术的喷涂移动热源模型。对模拟计算过程中所选用的喷涂速度、喷涂距离、颗粒粒径、送粉率等参数进行实地测量,建立了可行的喷涂流场数值模型和涂层温度场及应力场数值模型,对超音速火焰喷涂流场以及板状基体的涂层温度场和残余应力场进行了三维数值模拟。采用K型热电偶对观察点的喷涂热循环进行实测,通过金相法对涂层厚度进行实测,并采用多层涂层系统应力理论计算模型计算涂层残余应力值,验证数值模拟结果的可靠性。涂层温度场模拟结果与实测温度吻合良好,4个测量点的36个温度峰值的偏差均在15%以内,涂层残余应力场模拟结果与理论计算结果对比,48个对比的最大压应力值中,39个应力值的偏差在15%以内,最大偏差为29.24%。研究了不同枪管型号和不同粒径的喷涂颗粒对颗粒温度和速度的影响。颗粒直径越大,颗粒温度、速度越低,颗粒粒径为25um-30um时,颗粒的温度为1350-1500K,速度为410-460m/s;枪管越长,颗粒温度、速度越高,枪管型号为2和2L时,颗粒温度均为1400K左右,2L型号比2型号枪管模拟的颗粒速度高出40m/s。研究了不同空燃比和不同燃料流量对喷涂流场及颗粒温度和速度的影响。在枪管为2L,颗粒直径为25um条件下,控制丙烷流量为145SLPM时,空燃比为3.3时,颗粒温度最高,达到1430K,空燃比为3.1时,颗粒速度达到极大值445m/s;控制空燃比为3.2时,颗粒温度随丙烷流量的增大呈单调上升趋势,丙烷流量为1400SLPM时,颗粒温达到材料熔点温度(1388K),当流量超过150SLPM时,上升趋势增大。研究了颗粒温度、喷涂层数、对流条件对涂层残余应力的影响。随着喷涂层数的增加,涂层-基体界面处的切应力增大,X和Y方向的压应力减小;残余应力随颗粒温度的升高呈单调增大趋势,当颗粒温度超过1600K时,趋势增大;喷涂过程中对流换热越快,涂层-基体界面拉应力和压应力均呈减小趋势。
[Abstract]:In this paper, AK-07 type Kermetico, coating system for coating of Fe41Co7Mo14C15B6Y2 amorphous alloy coating for reference, based on the ANSYS software, using ICEM software for supersonic flame spraying fluid calculation regional grid, using FLUENT for supersonic flame spraying process by the numerical simulation of computational fluid dynamics software. By extracting the analysis of flow field and heat transfer coefficient of substrate surface the near wall temperature parameter, using parametric programming language ANSYS software of finite element program, established the spray moving heat source model based on the life and death element technology to simulate the spraying speed, the calculation process of spraying distance, particle size, powder feeding rate and other parameters were measured and a spray flow field the numerical model and the coating temperature field and stress field numerical model is feasible, the coating temperature and flow field of supersonic flame spraying plate matrix Temperature field and residual stress field were numerically simulated. The K type thermocouple spraying thermal cycle on the observation points were measured by metallographic test of coating thickness, and the multilayer coating system to calculate the residual stress in the coating value calculation model of stress theory, verify the reliability of numerical simulation results. The temperature field simulation the results are in good agreement with the measured temperature, the peak temperature deviation of 36 4 measuring points are less than 15%, compared with the results of calculation of field simulation results and the theoretical stress of coating residual pressure, the maximum stress value of the 48 comparison, 39 stress value of the deviation is within 15%, the maximum deviation of barrel type and different particle size of sprayed particles on temperature and velocity of the particles is 29.24%.. The increase of particle diameter, particle temperature, the lower the speed, the particle size of 25um-30um particles, the temperature is 1350-1500K, the speed is 410-46 0m/s; the longer the barrel, the particle temperature, the higher the speed, the barrel type 2 and 2L when the temperature of the particles are about 1400K, 40m/s. of different air-fuel ratio and different fuel flow rate on the temperature and velocity of flow and spray particles influence of particle velocity 2L models than the 2 models above. In the simulation of gun barrel is 2L, diameter is 25um under the control of propane flow is 145SLPM, the air-fuel ratio is 3.3, the highest reached 1430K, particle temperature, air-fuel ratio is 3.1, the particle velocity reaches a maximum value of 445m/s; control of the air-fuel ratio is 3.2, a significant increase trend with the temperature of the particles flow of propane increase of propane flow is 1400SLPM, particle temperature is up to the melting point temperature (1388K), when the flow exceeds 150SLPM, the rise of particles increases. Temperature, spray layer, convection effect on coating residual stress. With the increase of coating layers, the coating substrate industry The compressive stress at X and Y decreases as the shear stress increases, and the residual stress increases monotonously with the increase of particle temperature. When the particle temperature exceeds 1600K, the trend increases. The faster the convective heat transfer is, the less the tensile stress and the compressive stress of the coating matrix interface are.

【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG174.4

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