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为了探讨激光重熔对等离子喷涂常规和纳米热障涂层(TBCs)的影响,采用等离子喷涂工艺在γ-TiAl合金表面制备了常规和纳米ZrO2-7%Y2O3TBCs,并对其进行激光重熔处理,研究了等离子喷涂常规TBCs、激光重熔-等离子喷涂常规TBCs、等离子喷涂纳米TBCs及激光重熔-等离子喷涂纳米TBCs 4种涂层在850℃下的抗热震性能。结果表明:4种TBCs热震失效次数依次为73,118,146,163次,相应的热震破坏形式分别为整体剥落、局部剥落、边角剥落和局部剥落;纳米结构有利于提高涂层的抗热震性能;激光重熔在一定程度上改善了等离子喷涂层的抗热震性能。 相似文献
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等离子弧喷涂Al2O3陶瓷涂层低温抗热震性能的研究 总被引:1,自引:0,他引:1
为研究等离子弧喷涂Al2O3陶瓷涂层的低温抗热震性能,对不同结构的涂层进行了600 ℃低温热震试验,并分析、探讨了涂层的热震失效机制.结果表明,Al2O3陶瓷涂层低温下热震失效是由层间裂纹或层内裂纹引起的.对于单一Al2O3涂层,涂层与基体的界面是最薄弱处,层间裂纹的萌生及扩展导致涂层自界面处脱落;对于有FeCrAl金属过渡层的涂层,层内粒子间的结合是最薄弱处,层内片层间裂纹的萌生、扩展导致涂层局部脱落.在陶瓷工作层与基体间增加金属过渡层可有效地缓和涂层界面处的热应力,阻碍裂纹的形成及扩展,从而提高涂层的抗热震性能. 相似文献
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利用大气等离子喷涂技术,在N80钢基体上制备纳米掺杂Al2O3/ZrO2热障涂层。利用XRD、SEM等观察分析了纳米掺杂Al2O3/ZrO2粉末及等离子喷涂涂层组织形貌及结构,结果表明,Al2O3/ZrO2等离子喷涂粉末是由纳米包覆微米级粒子及少量的纳米团聚体球团粒子构成。纳米掺杂等离子喷涂Al2O3/ZrO2涂层的微观组织形貌复杂,存在着纳米柱状晶薄壳内包裹着微米级柱状晶、未熔化的ZrO2陶瓷粒子嵌镶在晶体内部的独特晶内结构。涂层主要由α-Al2O3及亚稳四方相t,-ZrO2相构成。 相似文献
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研究了等离子喷涂ZrO2-NiCoCrA1Y不同结构热障涂层的硬度分布800℃和1000℃温度下的热震性能。并进一步研究了去应力退火对涂层热震性能的影响。结果表明,与非梯度涂层相比,梯度涂层具有较平缓的硬度分布,不存在金属与陶瓷层界面间的硬度突变。热循环温度增加,使抗热震性能降低,但梯度涂层在两种温度下均具有较高的抗热震性。去应力退火处理较显著地提高了涂层的抗震性。 相似文献
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A microstructural study has been carried out of plasma-sprayed Al2O3 and mixed and sintered Al2O3Y2O3. In order to ascertain the degree of metastability achieved by plasma spraying, these results are compared with a similar experiment utilizing a CO2 laser for melting and the hammer-and-anvil technique for quenching of the same materials. X-ray diffraction methods were used to determine the obtained phases and crystal structures. In addition, transmission electron microscopy was used to confirm the phases present and to study their morpology. The porosity was studied with both mercury intrusion porosimetry and small angle neutron scattering. The addition of Y2O3 is shown to decrease the porosity from 15% to 7.5%. Adhesion is likewise related to the addition of Y2O3 and it is seen that adhesion of the mixture is measurably improved over that of pure Al2O3. The implication of these results is discussed. 相似文献
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黄孝华 《中国计量学院学报》1995,(1)
铁谱作为其他元素光谱的标识光谱,在摄谱法元素分析中占有重要地位.为了研究近年新研制出的微波等离子体炬的开发前景,我们用它作为激发光源,对FaCl3溶液进行摄谱研究.通过改变等离子体气流量、微波入射功率、焰炬上摄谱高度、曝光时间等条件,获取了具有对比性的谱板.对摄谱结果进行分析,本文总结出对FnCl3溶液较适宜的微波等离子体炬摄谱条件. 相似文献
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采用等离子反应合成技术,制备出了TiN/Ti3O复相陶瓷涂层,并分析了复相涂层的组织及其性能.研究结果表明:复相涂层主要由TiN相组成,并含有少量的钛的氧化物;复相涂层具有典型的层状组织结构,且层与层之间结合较好;制备的复相涂层的韧性得到明显提高,其韧性优于等离子喷涂Al2O3陶瓷涂层;特别是复相涂层具有优于M2钢的耐磨性. 相似文献
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Ali LEI Nan DONG Lajun FENG 《材料科学技术学报》2007,23(3):383-386
In order to overcome the limitations of low adhesion strength and poor thermal-shock resistance of pure ceramic coatings, Cu-Al2O3 gradient coatings were fabricated by plasma spraying. The microstructure and distribution of Cu-Al2O3 gradient coatings were analyzed. The adhesion strength, thermal-shock resistance and porosity of the coatings were tested. The results show that the composition of the gradient coatings has a gradient distribution along the thickness of coatings. As copper has a relatively low melting point and the molten copper has good wettability on the surface of Al2O3, it can be melted sufficiently and could fill the interstices and pores among the spraying particles effectively, thus improves the adhesion strength, thermal shock resistance and reduces the porosity. The adhesion strength of the gradient coating is 15.2 MPa which is two times of that of the double-layer structure coating. 相似文献
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新型荫罩式PDP效率三维模拟研究 总被引:1,自引:0,他引:1
针对目前PDP效率较低的问题,本文采用三维流体模型计算了新型荫罩式PDP(SMPDP)不同放电单元结构的放电特性和放电效率.在此基础上采用蒙特卡罗模型,研究了SMPDP放电单元中的光子辐射和捕获过程,给出了达到荧光粉层上的光子情况.研究了SMPDP结构电极宽度和位置以及气压和气体成分对放电效率的影响.设计了一种具有较高效率的荫罩式PDP结构,并提出了提高SMPDP效率的方法. 相似文献