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新型梯度功能陶瓷刀具材料的设计模型 总被引:3,自引:1,他引:2
本文首次提出对陶瓷刀具材料的组成分布,微观结构进行设计以形成梯度模型,通过不同组成分布的刀具工作过程中的热应力,机械应力及材料制备过程中的残余热应力进行了模拟,以使刀具材料内部形成与外载应力部分抵消的机制,从而提高陶瓷刀具抗磨损破损的性能。 相似文献
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陶瓷刀具材料的现状与发展 总被引:3,自引:0,他引:3
本文阐述了陶瓷刀具材料的发展现状 ,着重论述了氧化铝系陶瓷和氮化硅系陶瓷材料技术。对陶瓷刀具材料的发展趋势进行了综述。指出超微粉刀具、复相陶瓷刀具、涂层刀具及金属陶瓷是陶瓷刀具材料的研究方向。 相似文献
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通过力学性能数字试验模拟及校准,建立了碳化硅陶瓷的离散元模型和单点金刚石超精密切削加工的模型,并对其微加工过程进行了动态模拟;分析了在不同刀具前角、切削速度及切削深度等加工条件下残余应力随工件深度方向分布的影响。结果表明:当刀具前角处于小负前角时(–20°~0°),切削后的残余应力较小,否则当前角过大或者过小时,会产生较大的残余应力;残留在工件内的残余应力随切削速度以及切削深度的增加而增加。最后得出了不同加工条件下的残余应力云图,通过对残余应力产生机理的分析,验证了利用离散元法分析加工后材料的残余应力是可行的。 相似文献
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采用有限元分析软件ANSYS对等离子喷涂Sm2Zr2O7/YSZ双陶瓷层热障涂层界面残余热应力分布进行了数值仿真。结果表明:基体厚度不同时,涂层界面Sm2Zr2O7/YSZ及界面YSZ/NiCoCrAlY对应应力及应力梯度基本不变,表明应力及应力梯度与基体厚度无关;但基体材质热膨胀系数对涂层系统界面的径向、轴向及剪切应力梯度有决定性的影响,且各应力梯度随金属基体的热膨胀系数差异增加而增大,表明基体材质是影响涂层界面径向残余热应力及应力梯度的根本原因。采用多层陶瓷结构并合理选择各层材质的热膨胀系数将更加有利于降低涂层应力梯度,进而改善涂层性能,延长涂层寿命。 相似文献
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Al2O3—TiB2陶瓷刀具材料的研制及其耐磨性能研究 总被引:15,自引:0,他引:15
本文研制成功了一种新型陶瓷刀具材料即Al_2O_3-Ti B_2陶瓷刀具材料。文中讨论了该材料的研制方法,力学性能和微观结构特点,并对该材料的磨损行为和磨损机理进行了研究。结果表明:Ti B_2粒子的弥散可以明显提高该材料的耐磨性。加工淬火钢时该材料的抗磨损能力明显优于Al_2O_3-TiC陶瓷刀具材料。Al_2O_3-Ti B_2陶瓷刀具材料的磨损过程主要受粘着、耕犁和微破损机制的控制。 相似文献
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高分子材料以其优异的性能取代部分传统材料应用于民用、军用船舶领域。本文综述了船用高分子复合材料、船用功能高分子材料以及其他船用高分子材料的应用现状。民用船舶材料趋向于牢固耐用、强度更高、舒适安全,军用船舶材料除了具备上述特点之外,要求隐蔽性更强、作战能力更强。高分子材料的可设计性满足了船舶材料多方面的需求。可预计,高分子材料将在造船领域得到更为广泛的应用。 相似文献
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大力发展优质合成耐火原料 总被引:16,自引:9,他引:7
进入新世纪,应根据我国耐火原料资源丰富的优势,加快发展有自己特色的矾土基和镁砂基的优质合成耐火原料.它们可分为均质料、改性料、转型料三种类型. 相似文献
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Panagiotis Dimitrakellis Kosmas Ellinas Georgia D. Kaprou Dimitrios C. Mastellos Angeliki Tserepi Evangelos Gogolides 《大分子材料与工程》2021,306(4):2000694
The use of antibacterial surfaces is an effective way to reduce exposure to pathogens and therefore infections. Several methods to fabricate antibacterial surfaces using surface modification methods as well as a bactericidal agent incorporation inside materials have been reported. However, in most cases the factors affecting the antibacterial behavior of a surface are not discussed in detail. Here, a comparative study on the antibacterial properties of surfaces with different characteristics against Gram-negative bacteria (Escherichia coli) under dynamic conditions is presented, aiming to unravel the interplay among the most important factors when realizing an antibacterial surface, that is, surface morphology, wetting properties, and the use of a bactericidal agent. Significant bactericidal efficacy for the micro-nanotextured, superhydrophilic surfaces is demonstrated, possibly due to a mechanical killing induced by the interaction of bacteria with the micro-nanotopography. On the other hand, superhydrophobic surfaces without any bactericidal agent exhibit low interaction with the bacteria containing medium and therefore lower bactericidal action, whereas superhydrophobic surfaces with a bactericidal agent exhibit extreme non-wetting properties and rapid bactericidal effect through release of Cu particles. Finally, the role of the hydrophobic coating as barrier against uncontrolled release of the bactericidal agent when deposited as top layer is also showcased. 相似文献
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涂敷保温材料具有快速固化、负温施工等特殊性能。文章综述了涂敷保温材料的发展趋势,阐述了涂敷保温材料面临的问题,指出解决目前传统涂敷保温材料的热缺陷是进一步发展涂敷保温材料首要克服的困难。 相似文献
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“二氧化碳排放力争于2030年前达到峰值,努力争取2060年前实现碳中和”是中国对国际社会的庄重承诺。材料是实现碳减排技术的重要物质基础。通过介绍多尺度稀土新材料在能源存储、废气/尾气催化、电催化、永磁电机等领域应用的最新研究进展,分析了多尺度稀土新材料在攻坚双碳目标中发挥的作用。稀土是重要的“工业维生素”,着重介绍了稀土在原子离子、纳米微米、体块等尺度上对功能材料展现的独特作用。在量子材料方面,分析了稀土强关联固态电解质、稀土超导材料及稀土阻挫材料的最新研究进展。希望新型稀土功能材料的开发在减少碳排放方面起到促进作用。 相似文献
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A higher-ordered polysiloxane was prepared by the sol-gel reaction of (3-(2-aminoethylamino)propyl)trimethoxysilane in a hydrochloric acid aqueous solution without using any surfactants. The X-ray diffraction profile of the resulting polysiloxane showed three peaks with the d-value ratio of 1:1/√3:1/2, indicating that this polysiloxane has a hexagonal phase. The peaks shifted by changing the humidity. Therefore, we estimated that this hexagonal phase came from the stacking of a rodlike polymer with a Si-O-Si framework at the core and ammonium groups extruding outside. The TEM image of the polysiloxane showed a stripe pattern indicating an ordered arrangement. Because one repeating unit of the present polysiloxane has two ammonium groups, the ion-exchange capacity of this polysiloxane and viscosity of its aqueous solution were larger than those of the previous polysiloxane with single-ammonium group. 相似文献
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Niraj Kumar Ekta Kumari P. Siva Ram Krishna Ajay Kumar Kalyani 《Journal of the American Ceramic Society》2023,106(1):430-437
A new ferroelectric solid solution (1 − x)PbTiO3–xBi(Li1/2Nb1/2)O3 has been explored to develop high-temperature piezoelectric material. An interesting observation has been found regarding its Curie point (TC) and tetragonal lattice strain (c/a − 1). With increasing composition (x), the Curie point (TC) decreases up to x = 0.10 and thereafter remains constant. In concurrence with the TC, the tetragonal lattice strain (c/a − 1) follows a similar trend. Neutron powder diffraction analysis suggests this anomalous behavior is due to the robust off-centering characteristic of the Bi+3 ion 6S2 lone pair effect at the A-site compared to ions at B-site. 相似文献