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Al2 O3/Cr3C2/(W,Ti)C陶瓷抗弯强度的研究 总被引:2,自引:1,他引:1
热压烧结制备了Al2O3/Cr3C2/(W,Ti)C复合陶瓷材料,对其抗弯强度及组织形貌进行了研究,分析了Cr3C2与(W,Ti)C对抗弯强度的影响。结果表明:添加(W,Ti)C与Cr3C2有利于阻止晶界迁移,延缓晶粒长大,提高材料强度,但每一相的添加量以10%内为宜,两者添加总量在20%左右时Al2O3/Cr3C2/(W,Ti)C复合材料抗弯强度较佳。铬、钨、钛离子在Al2O3基体晶粒中的固溶起强化作用,网状结构是降低材料抗弯强度的重要原因。 相似文献
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AlN-TiB_2复相导电陶瓷的制备及性能研究 总被引:1,自引:0,他引:1
以微米Al N、微米Ti B2以及纳米Si C为主要原料,以微米Y2o3和微米Al2o3为添加剂,采用真空N2气氛保护热压烧结工艺制备了Al N-Ti B2复相导电陶瓷材料。测试和分析了烧结样品的相对密度、弯曲强度、硬度值以及导电性能。结果表明,当微米Al N添加量为55wt%,微米Ti B2为20wt%,纳米Si C为20wt%,微米Y2o3为3wt%以及微米Al2o3为2wt%时,且烧结温度为1880℃时,所制备的Al N-Ti B2复相导电陶瓷材料性能最佳,其相对密度为94.45%,弯曲强度为512.35MPa,洛氏硬度为104.25,电阻率值为1526μΩ.cm。 相似文献
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采用热压烧结工艺制备了 Si3N4 /( W,Ti) C复合陶瓷材料 ,并对材料的配方及烧结工艺进行了优化。研究表明 ,材料中 ( W,Ti) C的体积分数为 35 %时 ,可以获得良好的力学性能 ,抗弯强度为 845 MPa,显微硬度达到 1 6.45 GPa,断裂韧性达到 7.0 MPa· m1/2。研究过程中采用 XRD、SEM分析了材料的微观结构及组分变化 ,研究了烧结条件对材料性能的影响机理 ,结果表明 ,材料致密度的提高和显微组织的改变是其力学性能提高的根本原因 相似文献
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通过水热法制备粒度均匀的Al2O3/La2O3/(W,Mo)C纳米复合粉体,采用放电等离子烧结技术制备Al2O3/La2O3/(W,Mo)C无黏结相硬质合金刀具,利用激光加工技术在刀具表面制备不同沟槽参数的表面微织构,采用正交试验法研究不同沟槽参数的刀具对钛合金干切削性能的影响。结果表明:沟槽间距对切削力和粗糙度影响最大,沟槽深度次之,沟槽宽度影响最小;Al2O3/La2O3/(W,Mo)C无黏结相刀具在沟槽深度为10 μm、沟槽间距为100 μm、沟槽宽度为30 μm时,对TC4钛合金切削性能最好,且刀具前刀面无磨损,后刀面为边界磨损,沟槽织构有效抑制了月牙洼磨损,提高了刀具寿命。 相似文献
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Under machine grinding, material removal in monolithic Al2 O3 is by intergranular fracture and grain pull-out. In comparison, under the same grinding conditions, an Al2 O3 /5%SiC nanocomposite undergoes significant surface grooving and intragranular fracture. The subsurface deformation mechanisms were investigated by cross-sectional transmission electron microscopy. For Al2 O3 , the residual deformation zone was localized very close to the surface in the first layer of grains, with dislocations occurring only within 1.5 µm of the top surface and a high density of basal twins penetrating to a depth of one single grain. Cracks were present along grain boundaries or basal twin interfaces. For Al2 O3 /SiC nanocomposites, the main residual plastic deformation is observed to be dislocations activated to a depth of about 10 µm (approx. 3–4 grains), with twinning rarely observed. Possible mechanisms by which the SiC particles influence the subsurface deformation and material removal modes are discussed. 相似文献
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为了检测危害人类健康的异丙醇气体,本文制备了基于In_2O_3和Fe_2O_3负载In_2O_3(Fe_2O_3@In_2O_3)空心球的高灵敏度异丙醇气体传感器,通过表征手段对制备的In_2O_3和Fe_2O_3@In_2O_3样品的晶相,形貌和化学成分进行分析。实验测试结果表明,在200℃的最佳工作温度下,与纯的In_2O_3相比,Fe_2O_3@In_2O_3空心球气体传感器对异丙醇有更好的气敏特性。Fe_2O_3@In_2O_3空心球传感器对100×10~(-4)%异丙醇的响应值可达28.2 (为纯相In_2O_3的1.75倍),响应时间为1 s,恢复时间为2 s,且重复性和稳定性良好。Fe_2O_3与In_2O_3两种氧化物之间形成了n-n异质结,提高了传感器的初始电阻,从而优化了In_2O_3的气敏特性。本文所制备的Fe_2O_3@In_2O_3空心球传感器在检测异丙醇气体方面具有广泛的应用前景。 相似文献
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针对纯水液压元件摩擦副实际工况,研究了水润滑状态下Al2O3和Al2O3 13%TiO2等离子喷涂试环分别与整体烧结Al2O3块之间的摩擦磨损特性,考察了摩擦系数及试环磨损量随时间的变化,利用扫描电子显微镜(SEM)观察了磨痕的表面形貌,利用X射线能量色散谱仪分析了磨痕表面的元素组成。研究结果表明:水润滑条件下两种摩擦副的磨损机理主要是脆性断裂、微切削与腐蚀磨损;摩擦副Al2O3环/整体烧结Al2O3块的摩擦学性能优于Al2O3 13%TiO2/Al2O3块,它们更适合作为纯水液压元件的摩擦副材料。 相似文献
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Al2O3/Cu composites (1.0 vol%) reinforced with different size of α-Al2O3 particles were fabricated by a powder metallurgy method and electrical sliding wear tests were performed on a self-made pin-on-disk electrical wear tester. The effect of Al2O3 particle size on electrical wear performance of the Al2O3/Cu composite was studied, and the wear mechanism of the Al2O3/Cu composite was also discussed based on worn surface observations. The results show that the tribological properties of A12O3/Cu composite are closely related to the mechanical properties. With an increase in Al2O3 particle size, the wear rates of A12O3/Cu composites have a reverse variation with hardness of A12O3/Cu composites. In the range of 50–100 nm, Al2O3/Cu composites have the highest wear resistance and mechanical properties. Microstructural observation revealed that the wear mechanisms of Al2O3/Cu composites were mainly adhesive wear and plastic deformation accompanied by a small amount of arc damage. In addition, the plastic deformation area on the pin sample of the frictional end depends on the electrical wear resistance of A12O3/Cu composites. 相似文献
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Shikhgasan Ramazanov Dinara Sobola Ştefan Ţălu Farid Orudzev Ali Arman Pavel Kaspar Rashid Dallaev Guseyn Ramazanov 《Microscopy research and technique》2022,85(4):1300-1310
Thin films of bismuth and iron oxides were obtained by atomic layer deposition (ALD) on the surface of a flexible substrate poly(4,4′-oxydiphenylene-pyromellitimide) (Kapton) at a temperature of 250°C. The layer thickness was 50 nm. The samples were examined by secondary-ion mass spectrometry, and uniform distribution of elements in the film layer was observed. Surface morphology, electrical polarization, and mechanical properties were investigated by atomic force microscope, piezoelectric force microscopy, and force modulation microscopy. The values of current in the near-surface layer varied in the range of ±80 pA when a potential of 5 V was applied. Chemical analysis was performed by X-ray photoelectron spectroscopy, where the formation of Bi2O3 and Fe2O3 phases, as well as intermediate phases in the Bi–Fe–O system, was observed. Magnetic measurements were carried out by a vibrating sample magnetometer that showed a ferromagnetic response. The low-temperature method of functionalization of the Kapton surface with bismuth and iron oxides will make it possible to adapt the Bi–Fe–O system to flexible electronics. 相似文献
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本文采用TEM中电子衍射与暗场技术,XRO及EPMA等方法研究了ZrO2-2~20mol%Y2O3陶瓷在不同热处理工艺条件下的组织结构。结果表明,对Y2O3含量较低(2mol%)的试样烧结后得到晶粒细小的正方ZrO2-(TZP)组织;在从高温立方单相区快速冷却的3~7.5mol%Y2O3试样中形成反相畴界与相变孪晶组织;在c+t双相区长时间等温退火处理的4~6mol%Y2O3试样中,在立方相基体上析出正方相粒子而得到部分稳定ZrO2(PSZ),初期阶段形成“tweed”组织,后期阶段形成“colony”组织;在14mol%及20mol%Y2O3试样中则形成全稳定ZrO2(FSZ)。 相似文献