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1.
Study of plasma- and detonation gun-sprayed alumina coatings using taguchi experimental design 总被引:1,自引:0,他引:1
P. Saravanan V. Selvarajan M. P. Srivastava D. S. Rao S. V. Joshi G. Sundararajan 《Journal of Thermal Spray Technology》2000,9(4):505-512
Atmospheric plasma spraying (APS) is a most versatile thermal spray method for depositing alumina (Al2O3) coatings, and detonation gun (D-gun) spraying is an alternative thermal spray technology for depositing such coatings with
extremely good wear characteristics. The present study is aimed at comparing the characteristics of Al2O3 coatings deposited using the above techniques by using Taguchi experimental design.
Alumina coating experiments were conducted using a Taguchi fractional-factorial (L8) design parametric study to optimize the spray process parameters for both APS and D-gun. The Taguchi design evaluated the
effect of four APS and D-gun spray variables on the measured coating attributes. The coating qualities evaluated were surface
roughness, porosity, microhardness, abrasion, and sliding wear. The results show that the coating quality is directly related
to the corresponding coating microstructure, which is significantly influenced by the spray parameters employed. Though it
is evident that the D-gun-sprayed coatings consistently exhibit dense and uniform microstructure, higher hardness, and superior
tribological performance, the attainment of suitable plasma-sprayed coatings can be improved by employing the Taguchi analysis. 相似文献
2.
M. J. Jackson G. M. Robinson W. Ahmed H. Sein A. N. Jones N. Ali E. Titus Q. H. Fan J. Gracio 《Journal of Materials Engineering and Performance》2005,14(2):163-172
This article investigates the role of substrate temperature in the deposition of diamond films using a newly developed time-modulated
chemical vapor deposition (TMCVD) process. TMCVD was used to deposit polycrystalline diamond coatings onto silicon substrates
using hot-filament chemical vapor deposition system. In this investigation, the effect of (a) substrate temperature and (b)
methane (CH4) content in the reactor on diamond film deposition was studied. The distinctive feature of the TMCVD process is that it time-modulates
CH4 flow into the reactor during the complete growth process. It was noted that the substrate temperature fluctuated during the
CH4 modulations, and this significantly affected some key properties of the deposited films. Two sets of samples have been prepared,
in each of which there was one sample that was prepared while the substrate temperature fluctuated and the other sample, which
was deposited while maintaining the substrate temperature, was fixed. To keep the substrate temperature constant, the filament
power was varied accordingly. In this article, the findings are discussed in terms of the CH4 content in the reactor and the substrate temperature. It was found that secondary nucleation occurred during the high timed
CH4 modulations. The as-deposited films were characterized for morphology, diamond-C phase purity, hardness, and surface roughness
using scanning electron microscopy, Raman spectroscopy, Vickers hardness testing, and surface profilometry, respectively. 相似文献
3.
采用Taguchi方法和灰色关联分析对Al356/SiC-云母混合金属基复合材料的钻削工艺参数进行优化。实验采用L18正交阵列,在计算机的控制立式机床上进行。考察的钻削性能指标包括轴向力、表面粗糙度、刀具磨损和毛刺高度,对影响这些性能的钻削工艺参数进行了优化,包括轴转数、给进速度、钻头类型和云母质量分数。结果表明:给进速度和钻头类型是影响钻削过程的重要因素,通过这种方法可以有效地改进钻削工艺的性能。 相似文献
4.
The efficiency and competitiveness of using nanomaterials can be increased through introducing scientific experimental designs. For obtaining experimental models which can better approximate the real technological systems, a sufficient number of control factors and of necessary experiment units should be taken into account, having in view their economical aspect, too. Considering the importance of Ag-doped TiO2 nanoparticles in such domains as industry, environmental protection, health, etc., it is important for manufacturers to obtain nanoparticles of equal dimensions. The present paper is analyzing the ways of improving dimensional stability of Ag-doped TiO2 nanoparticles produced by the microwave-hydrothermal (M-H) method. In one case, a two-level L8 Taguchi design was used in 8 experiments, with seven control factors. In the other case, the Draper-Lin design of 40 experiments for 7 factors at two levels was utilized. It has been found out that the L8 Taguchi experimental design offers the same results as the Draper-Lin experimental design, but with much fewer experiments. 相似文献
5.
目的通过正交实验优化不锈钢表面纳米孔制备工艺。方法通过田口实验方法设计正交试验优化工艺。采用含有氯化钠和硫脲的硝酸溶液阳极氧化制备纳米孔,在含有氯化钠、盐酸和硫酸的水溶液中进行扩孔处理。通过扫描电子显微镜、能谱仪对表面处理后的试样表面形貌和元素进行分析,应用软件统计SEM图片孔隙率,并将孔隙率作为响应指标,利用极差分析和方差分析研究阳极氧化工艺和扩孔时间对表面形貌及孔隙率的影响,并优化工艺参数。结果 SEM照片和5个水平的均值表明,硝酸浓度的提高有利于提高孔隙率,较高的硫脲浓度有利于形成均匀有序的纳米孔结构,氯化钠浓度、氧化时间、氧化电压和扩孔时间对表面形貌和孔隙率影响不明显。元素分析表明,纳米孔的材料仍然是不锈钢,而不是金属氧化物。正交实验优化的工艺参数是:硝酸的体积浓度为90 mL/L,硫脲的质量浓度为3.5 g/L,氯化钠的质量浓度为20 g/L,氧化时间为120 s,氧化电压为5.0 V,扩孔时间为50 s。结论通过实验验证,优化后的工艺能够制备出表面较平整、孔隙率较高的纳米孔结构。 相似文献
6.
M. Yousefieh M. Shamanian A. Saatchi 《Journal of Materials Engineering and Performance》2012,21(9):1978-1988
Taguchi design method with L9 orthogonal array was implemented to optimize the pulsed current gas tungsten arc welding parameters for the hardness and the toughness of super duplex stainless steel (SDSS, UNS S32760) welds. In this regard, the hardness and the toughness were considered as performance characteristics. Pulse current, background current, % on time, and pulse frequency were chosen as main parameters. Each parameter was varied at three different levels. As a result of pooled analysis of variance, the pulse current is found to be the most significant factor for both the hardness and the toughness of SDSS welds by percentage contribution of 71.81 for hardness and 78.18 for toughness. The % on time (21.99%) and the background current (17.81%) had also the next most significant effect on the hardness and the toughness, respectively. The optimum conditions within the selected parameter values for hardness were found as the first level of pulse current (100 A), third level of background current (70 A), first level of % on time (40%), and first level of pulse frequency (1 Hz), while they were found as the second level of pulse current (120 A), second level of background current (60 A), second level of % on time (60%), and third level of pulse frequency (5 Hz) for toughness. The Taguchi method was found to be a promising tool to obtain the optimum conditions for such studies. Finally, in order to verify experimental results, confirmation tests were carried out at optimum working conditions. Under these conditions, there were good agreements between the predicted and the experimental results for the both hardness and toughness. 相似文献
7.
The Taguchi method of experimental design is very well suited to improving the production process of synthetic bone grafts for several reasons. Firstly, the effect of many different process variables can be examined simultaneously, which ensures that beneficial factor combinations are not overlooked. Secondly, it is very efficient and easy to apply, so that it does not require large amounts of time or resources to conduct a given set of experiments. This makes it possible to conduct a series of experiments that result in continuous process improvement. Finally, using a Taguchi signal-to-noise ratio permits the concurrent optimization of the process and the reduction of process variability. The ease of use, efficiency, and focus on decreasing variability while optimizing the response more than outweigh the disadvantage of the Taguchi method of experimental design, as compared with the many other experimental approaches currently in use.The current application of the Taguchi method was successful in optimizing the mechanical properties of the Si-mHA synthetic bone grafts. The compression strength was doubled while maintaining the appropriate porosity level and microstructure for bioactivity. The mean value of the compression strength obtained was 5.8 MPa with a density of 0.515 gm/cm3. Three levels of porosity were identified namely, macro-, meso-, and micro-porosity. The mean values of pore sizes were 400, 100 and 6 μm, respectively. By using the Taguchi method in conjunction with a statistical experimental design, the various steps of the scaffold production process such as slurry preparation, coating process, drying, calcining and sintering processes were optimized. The final optimized process gave highly reproducible results. The manner in which the Taguchi method was used to produce synthetic bone scaffolds with desired properties is described. 相似文献
8.
Chyn-Shu Deng Jen-Chen Huang Jih-Hua Chin 《International Journal of Machine Tools and Manufacture》2001,41(8)
This work investigates the effect of drill shaft support misalignment on hole straightness in relation to the various control factors. Misalignments occur in machine spindles, intermediate supports and pilot bushings. Equations for axial hole straightness deviation are derived herein using the Euler column theory, and experiments are performed using Gundrill and BTA deep-hole drilling systems. Simulation results, Sakuma's method and experimental examinations are also presented. Taguchi methods and statistical techniques are used to formulate the experimental layout, analyze the effect of each control factor on the results, and optimize the setting for each control factor. Further experiments then verify these estimates. Six control factors were used in a modified L8 orthogonal array design. The confirmatory experiments revealed an average straightness deviation within the 95% confidence interval. 相似文献
9.
在奥氏体不锈钢与铜合金异种材料摩擦焊接过程中,采用响应面方法优化摩擦焊接工艺参数,以获得抗拉强度最大和界面硬度最小的焊接接头。采用三因素、五水平中心复合正交矩阵来确定实验条件。得到20个焊接接头,测定了焊接接头的抗拉强度和界面硬度。采用方差分析(ANOVA)方法来确定起显著作用的、主要的及相互作用的参数,使用回归分析得到经验关系模型。用设计专家软件构造响应图和等高线图来优化摩擦焊接工艺参数。用得到的经验关系模型可以有效地预测焊接接头的抗拉强度和界面硬度,其置信水平达95%。从形成的等高线图可以得到所需的摩擦焊接的最佳条件。 相似文献
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J. Simao H. G. Lee D. K. Aspinwall R. C. Dewes E. M. Aspinwall 《International Journal of Machine Tools and Manufacture》2003,43(2):5989
Electrical discharge machining (EDM) is a widely used process in the mould / die and aerospace industries. Following a brief summary of the process, the paper reviews published work on the deliberate surface alloying of various workpiece materials using EDM. Details are given of operations involving powder metallurgy (PM) tool electrodes and the use of powders suspended in the dielectric fluid, typically aluminium, nickel, titanium, etc. Following this, experimental results are presented on the surface alloying of AISI H13 hot work tool steel during a die sink operation using partially sintered WC / Co electrodes operating in a hydrocarbon oil dielectric. An L8 fractional factorial Taguchi experiment was used to identify the effect of key operating factors on output measures (electrode wear, workpiece surface hardness, etc.). With respect to microhardness, the percentage contribution ratios (PCR) for peak current, electrode polarity and pulse on time were ˜24, 20 and 19%, respectively. Typically, changes in surface metallurgy were measured up to a depth of ˜30 μm (with a higher than normal voltage of ˜270 V) and an increase in the surface hardness of the recast layer from ˜620 HK0.025 up to ˜1350 HK0.025. 相似文献
13.
T. J. Steeper D. J. Varacalle G. C. Wilson W. L. Riggs A. J. Rotolico J. Nerz 《Journal of Thermal Spray Technology》1993,2(3):251-256
This article presents an experimental study of the plasma spraying of alumina- titania powder. This powder system is being
used to fabricate heater tubes that emulate nuclear fuel tubes for use in thermal-hydraulic testing. Coating experiments were
conducted using a Taguchi fractional- factorial design parametric study. Operating parameters were varied around the typical
spray parameters in a systematic design of experiments to display the range of plasma processing conditions and their effect
on the resultant coating. The coatings were characterized by hardness and electrical tests, image analysis, and optical metallography.
Coating qualities are discussed with respect to dielectric strength, hardness, porosity, surface roughness, deposition efficiency,
and microstructure. The attributes of the coatings are correlated with the changes in operating parameters. 相似文献
14.
Mohammad Yousefieh Morteza Tamizifar Seyed Mohammad Ali Boutorabi Ehsan Borhani 《Journal of Materials Engineering and Performance》2016,25(10):4239-4248
In this study, Taguchi design method with L9 orthogonal array has been used to optimize the initial thickness and pre-aging parameters (temperature and time) for the mechanical properties of Al-0.2 wt.% Sc alloy heavily deformed by accumulative roll bonding (ARB) up to ten cycles. Analysis of variance was performed on the measured data and signal-to-noise ratios. It was found that the pre-aging temperature has the most significant parameter affecting the mechanical properties by percentage contribution of 64.51%. Pre-aging time (19.29%) has the next most significant effect, while initial thickness (5.31%) has statistically less significant effect. In order to confirm experimental conclusions, verification experiments were carried out at optimum working conditions. Under these conditions, the yield strength was 6.51 times higher and toughness was 6.86% lower compared with the starting Al-Sc material. Moreover, mean grain size was decreased to 220 nm by setting the control parameters, which was the lowest value obtained in this study. It was concluded that the Taguchi method was found to be a promising technique to obtain the optimum conditions for such studies. Consequently, by controlling the parameter levels, the high-strength and high-toughness Al-Sc samples were fabricated through pre-aging and subsequent ARB process. 相似文献
15.
D. J. Varacalle G. C. Wilson R. W. Johnson T. J. Steeper G. Irons W. R. Kratochvil W.L Riggs 《Journal of Thermal Spray Technology》1994,3(1):69-74
An experimental study was conducted on the twin- wire electric arc spraying of aluminum coatings. This aluminum wire system
is being used to fabricate heater tubes that emulate nuclear fuel tubes for use in thermal-hydraulic experiments. Experiments
were conducted using a Taguchi fractional factorial design parametric study. Operating parameters were varied around the typical
process parameters in a systematic design of experiments to display the range of processing conditions and their effect on
the resultant coating. The coatings were characterized by hardness tests, optical metallography, and image analysis. This
article discusses coating hardness, roughness, deposition efficiency, and microstructure. The study attempts to correlate
the features of the coatings with the changes in operating parameters. A numerical model of the process is presented, including
gas, droplet, and coating dynamics. 相似文献
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目的 提高激光冲击强化(Laser Shock Peening,LSP)表面硬度的在线检测能力,探究声发射信号关键帧对LSP表面硬度分类识别性能的影响。方法 在LSP处理期间声发射弹性波(Acoustic Emission,AE)具有与材料内部晶格位错和塑性变形密切相关的动态信息,是激光冲击强化在线监测的一种极具潜力的手段。但其高采样频率导致大量的实时计算,对在线监测技术的工业应用提出了巨大的挑战。为解决这一问题,提出了注意力权重统计方法获取激光冲击强化过程中声发射信号的关键帧。结果 四通道传感器各自的关键帧信号长度相比原始信号的有效长度均大幅度减少,最大可减少83.74%,相比原始数据每一轮测试(350个冲击样本),最大可减少57.37%的测试时间。关键帧信号的模型识别准确率最高可达到97.04%,相比原始数据集提升了2.93%。结论 与原始声发射信号相比,关键帧信号得到了更高的测试准确率,同时有效地减少了数据量。基于关键帧数据集的最高准确率和最短测试时间,评价了4种不同传感器中信号采集的最佳传感器,其结果可作为LSP质量监测领域的参考。 相似文献
18.
D. J. Varacalle M. G. Ortiz C. S. Miller T. J. Steeper A. J. Rotolico J. Nerz W. L. Rlggs 《Journal of Thermal Spray Technology》1993,2(2):151-158
A major trend in the thermal spray industry has been to increase the gas jet velocity to obtain better coating attributes.
One emerging technology now used in industry is the high-velocity oxygen fuel process (HVOF). High-velocity spray guns combine
oxygen and a fuel gas to generate heat and extremely high particle velocities. In this study, Inconel 718 powder was deposited
on steel substrates. The primary coating function was electrical resistivity for a heater application. Experiments were conducted
using a Taguchi L8 statistical fractional/factorial design parametric study. The Taguchi experiment evaluated the effect of
six HVOF processing variables on the measured responses. The parameters were oxygen flow, fuel flow, air envelope gas flow,
powder feed rate, spray distance, and nozzle configuration. The coatings were characterized by hardness tests, surface profilometry,
optical metallography, and image analysis. This article investigates coating hardness, porosity, surface roughness, deposition
efficiency, and microstructure with respect to the influence of the processing parameters. Analytical studies were conducted
to investigate gas, particle, and coating dynamics for two of the HVOF thermal spray experiments. 相似文献
19.
Three iterations of Taguchi designed experiments and analyses were used to determine optimal thermal treatments for minimizing
retained austenite content while maximizing Rockwell hardness (HRC) in AISI 52100 bearing steel. Experimental variables chosen
for this study included austenitizing and tempering temperatures, tempering time and cold treatment. After one iteration,
tempering temperature and cold treatment were seen to have the greatest effect on austenite content while austenitizing and
tempering temperatures had the greatest influence on hardness. After the second and third experimental iterations, two thermal
treatments were noted each producing hardness of 58–59 HRC in combination with zero retained austenite as measured by x-ray
diffraction. 相似文献
20.
This study investigated multi-response optimization of the pulse metal active gas-tungsten inert gas( PMAG-TIG) twin arc hybrid root welding process for an optimal parametric combination to yield favorable back bead geometry of welded joints using grey relational analysis and Taguchi method.Eighteen experimental runs based on an orthogonal array following the Taguchi method were performed to derive objective functions to be optimized within the experimental domain.The objective functions were selected in relation to parameters of PMAG-TIG twin arc root welding back bead geometry: back bead width to root reinforcement ratio and deposited metal height.The Taguchi approach was followed by grey relational analysis to solve the multi-response optimization problem.The significance of factors on overall quality characteristics of the weld joint was also evaluated quantitatively using analysis of variance.Optimal results were verified through additional experiments,and showed to feasibility of applying grey relation analysis in combination with Taguchi technique for continuous improvement of product quality in the manufacturing industry. 相似文献