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通过疲劳磨损比较试验、接触疲劳强度试验和Mg-PSZ陶瓷蜗轮的模拟试验,分析出了陶瓷材料的疲劳磨损计算公式,试验结果表明:陶瓷试件的磨损量较金属试件小;磨损机制主要是磨粒磨损.在不同的振动条件下,Mg—PSZ陶瓷较Al2O3和ZTA(ZrO2增韧Al2O3)陶瓷的接触疲劳强度高,疲劳寿命长,最适合作轻微冲击载荷作用下陶瓷摩擦副零件. 相似文献
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MgO 掺杂的 ZrO_2 的电导率研究 总被引:2,自引:0,他引:2
用复数阻抗平面图法测定了 MgO 掺杂的 ZrO_2的电导率。在所研究的组成范围内,随着 MgO 的含量从4.7mol%增加到约8.2mol%时,电导率增加并达到一个峰值。在1000℃时,含8.2mol% MgO 的 ZrO_2 σ=2.43×10~(-2)(Ω·cm)~(-1)。当 MgO 含量进一步增加时,电导率逐步降低。由于 ZrO_2的单斜相与四方相之间的转变在电导率-温度的函数关系上,于900—1150℃的范围内观察到升温与降温过程所形成的热迥线现象。表明除了立方萤石型结构的 ZrO_2外,四方固溶体的 ZrO_2也具有高的氧离子电导率。在“空气,Pt|ZrO(MgO)|Pt,O_2+N_2”型的氧浓差电池中测定了固体电解质的氧离子迁移数,并对结果进行了讨论. 相似文献
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为研究连铸用氧化锆质定径水口在使用温度下矿物组成和微观结构,对以氧化镁部分稳定氧化锆(Mg-PSZ)为原料制备的定径水口产品进行模拟实验研究.实验条件为:模拟浇钢使用条件试样在1540℃×5h后水淬冷却,模拟翻包后自然冷却条件试样在1540℃×5h后随炉冷却.借助X-ray荧光分析仪、X-ray衍射仪、扫描电子显微镜对试样的矿物组成及显微结构进行表征.研究结果表明:以Mg-PSZ制备的氧化锆质定径水口产品在1540℃浇钢温度下矿物相以立方相为主,在翻包自然冷却过程中,缓慢的冷却速率导致部分立方相转变为单斜相,矿物相以单斜相氧化锆为主.氧化锆质定径水口产品在高温使用环境中结构均匀,平均颗粒尺寸10 μm,而翻包自然冷却后,由于缓慢的冷却速率,定径水口产品中稳定剂脱溶,导致立方相转变为单斜相氧化锆,平均颗粒尺寸7 μm.即通过翻包自然冷却后所取试样的研究结果不能代表氧化锆质定径水口在中间包浇注过程中实际使用状态. 相似文献
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Mg—PSZ陶瓷热处理与四方析体马氏体相变温度关系的研究 总被引:2,自引:1,他引:1
采用带有液氮负温裝置的LK-02型高速淬火膨胀仪对已获得工业应用的、含10mol%MgO的Mg-PSZ陶瓷的热处理条件与其中t-ZrO_2的马氏体相变温度(M_4、M_6)及可相变t-ZrO_7析体量的关系进行了研究,认为:t-ZrO_2析体的粒径及其热处理过程中的应力应变状态是决定或影响马氏体相变温度高低和在应力诱导下可相变t-ZrO_2量的两个基本因素;采取1420℃和1100℃的综合热处理,与在1420℃或1100℃进行单一温度热处理相比,易于控制M、和M_4值,且能保证较高的可相变t-ZrO_7析体量,是优化Mg-PSZ结构和性能的一种值得进一步进行研究的热处理工艺。经1100℃、4b热处理的Mg-PSZ试样的“Δl-T”曲线的低温端未观察到明显的表征马氏体相变的膨胀效应。 相似文献
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《应用陶瓷进展》2013,112(4):200-203
The scavenging effect of magnesium oxide (MgO) addition on electrical property of 9 mol-% MgO partially stabilised zirconia (Mg-PSZ) was investigated in terms of phase transformation and intergranular phase formation. The addition of MgO up to 5 mol-% caused a stabilisation of Mg-PSZ, which led to an increase in the cubic phase and a decrease in the monoclinic and tetragonal phases in Mg-PSZ. The Mg-PSZ with the addition of 5 mol-% of MgO also exhibited the maximum ionic conductivity (0.3915?S?cm?1 at 1500°C) and forsterite (Mg2SiO4) was observed on the grain boundaries of Mg-PSZ. The intergranular phases, formed by reactions between the silicon in Mg-PSZ and MgO addition, reduced the grain boundary resistance, because the siliceous phase which is a hindrance for oxygen ion conduction was scavenged by the formation of Mg2SiO4. 相似文献
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R. Fernandez D. Casellas F.L. Cumbrera F. Sanchez-Bajo M. Anglada L. Llanes 《International Journal of Refractory Metals and Hard Materials》1998,16(4-6):291-301
A detailed investigation on the relationships between phase assemblage and fracture and fatigue characteristics of Mg-PSZ has been conducted. In doing so, three completely different microstructural conditions were first attained through different thermal treatments and then their flexural strength, fracture toughness and crack growth resistance and fatigue crack growth (FCG) behaviour were evaluated. The obtained results are discussed considering the interplay between microstructural features and dominant crack-microstructure interaction and its influence on the operation of given toughening and mechanical fatigue mechanisms for each phase assemblage studied. FCG resistance, under both sustained and cyclic loading, is found to be closely related to the corresponding fracture toughness of each phase assemblage. However, real mechanical fatigue effects are estimated to be, once they are rationalized with respect to particular environmental-assisted cracking behaviours, an exclusive function of crack path type. Finally, different cyclic fatigue mechanisms for Mg-PSZ are pinpointed depending upon the prevalent transgranular or intergranular FCG morphology. 相似文献
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