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激光熔覆Al2O3+TiO2复合陶瓷涂层的微观结构 总被引:12,自引:0,他引:12
研究了45#钢表面Al2O3+TiO2复合陶瓷激光熔覆层的微观组织和相结构、Al2O3+TiO2复合陶瓷激光熔覆涂层由α-Al2O3,TiO2,γ-TiO2,γ-Al2O3及Al2TiO5相组成,消除了等离子喷涂层的层状组织特征,形成了大致方向的柱状晶,晶内为溶入了Ti及少量底层元素的α-Al2O3;晶界为由TiO2和Al2O3形成的Al2TiO5相,溶有少量的Cr,Fe,Y取代了Al2TiO5 相似文献
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新型复相陶瓷刀具材料Jx-2-I协同增韧补强机理的研究 总被引:1,自引:0,他引:1
本文研制成功的新型陶瓷刀具材料—SiC晶须(SiCw)增韧和SiC颗粒弥散增韧Al2O3陶瓷刀具Jx-2-I,该刀具材料具有高的抗弯强度和断裂韧性等优点;对比A(Al2O3)、AP(Al2O3/SiCp)、AW(Al2O3/SiCw)、Jx-1(Al2O3/SiCw)和Jx-2-1(Al2O3/SiCp/SiCw)等陶瓷材料的力学性能可以看出,在Jx-2-I材料中具有明显的增韧补强叠加效应;本文在热失配分析和微观结构观察的基础上详细研究了Jx-2-I刀具材料的增韧补强机理,系统研究了Jx-2-I中各种增韧补强机理之间的协同效应。 相似文献
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采用超声-放电复合加工技术对Al2O3/(W,Ti)C,Al2O3/TiB2,Al2O3/TiB2/SiCw三种Al2O3基陶瓷刀具材料表面定位方孔进行加工,研究了共加工机理和加工参数对不同陶瓷材料加工效率,加工表面粗糙度的影响,由于该复合加工技术有产地结合了超扬波加工和放电加工的特点,因而能高效,高质量地加工陶瓷材料。试验结果表明,在同样的加工条件下,材料去除率的大小顺序为Al2O3/(W,Ti 相似文献
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本文对重庆仪表材料研究所研制的40TiO2-Al2O3球形喷涂粉末的物理性能和涂层性能进行了分析讨论。结果表明,该球形粉末相对于其它40TiO2-Al2O3粉末,具有显著的球状特征,由此带来流动性好,熔化特性均一的优点,因而其工艺性能良好,制得的涂层性能优良。 相似文献
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氧化对Al2O3—TiB2陶瓷刀具材料磨损特性的影响 总被引:4,自引:0,他引:4
研究了Al2O3-TiB2陶瓷刀具材料的高温氧化特性以及氧化对刀具耐磨性能的影响。结果表明,随TiB2含量的增加,Al2O3-TiB2的氧化活化能降低,抗化能力下降。Al2O3-TiB2刀具材料在加工淬火钢时,因切削高温的氧化作用在刀具表面生成的TiO2既可将轻刀具的粘结磨损,又能起到固体润滑剂的作用,从而降低摩擦系数,因而提高刀具的耐磨性能。 相似文献
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Al2O3陶瓷基体中原位生成TiB2和Ti(C,N)研究 总被引:6,自引:0,他引:6
采用原位反应法结合热压工艺制备Al2O3-TiB2-Ti(C,N)复相陶瓷,用TiO2,B4C,BN,Al及Al2O3为原料,通过组成设计可以制备出不同相组成及碳氮比的复相陶瓷。由SEM及TEM发现在Al2O3晶粒中分布着亚微米至微米级的近圆形Ti(C,N)颗粒,而在TiB2晶粒中分布着纳米级的板状Ti(C,N)晶体,并对这种显微结构的形成机理及化学反应过程作用初步分析。 相似文献
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W18Cr4V钢表面激光熔覆Al2O3陶瓷涂层的组织结构 总被引:7,自引:0,他引:7
研究了W18Cr4V钢表面Al2O3/NiCrAl复合陶瓷涂层的组织结构、成分分布及界面组织特征。结果表明:Al2O3/NiCrAl复合陶瓷等离子喷涂层的组织呈层片状,面层由α-Al2O3和少量的γ-Al2O3组成,层间为机械结合界面,界面处成分变化梯度较大。经激光重熔后的面层组织为单一的α-Al2O3柱状晶,Al2O3与中间合金NiCrAl间存在明显的界面反应,且界面相增多,在NiCrAl与基体 相似文献
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研究了Al_2O_3-TiB_2陶瓷刀具材料的高温氧化特性以及氧化对刀具耐磨性能的影响。结果表明:随TiB_2含量的增加,Al_2O_3-TiB_2的氧化活化能降低,抗氧化能力下降.Al_2O_3-TiB_2刀具材料在加工淬火钢时,因切削高温的氧化作用在刀具表面生成的TiO_2既可减轻刀具的粘结磨损,又能起到固体润滑剂的作用,从而降低摩擦系数,因而提高刀具的耐磨性能。当切削速度大于150m/min时,随TiB_2含量的增加,刀具抗磨损能力显著提高。 相似文献
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《Ceramics International》2020,46(10):15949-15957
Nano CaF2 particles of different sizes were prepared by direct precipitation. The diameters of nano CaF2 particles prepared in mixed solvent can reach 5–7 nm, and can be effectively dispersed. The surface of nano CaF2 was modified and coated by heterogeneous nucleation method. A shell layer of Al(OH)3 was coated on the surface of nano CaF2, and the structure and coating mechanism of the coated powder were analyzed. Under varying preparation conditions, the surface morphology of CaF2@Al(OH)3 was analyzed using TEM and SEM. The results showed that the coating powder showed good dispersion in mixed solvents, and the particle size of the composite powder was about 20 nm. Self-lubricating ceramic tool materials were prepared by adding coating particles to the Al2O3/Ti(C,N) matrix. The coating powder shell and the matrix material melt during sintering, so that CaF2 forms nanostructures in the particles. thereby improving the mechanical properties of the material. Cutting experiments show that the addition of coating particles can effectively reduce the temperature, cutting force and friction coefficient in the cutting process of the tool, thus improving the cutting performance of the tool material. 相似文献
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Jingjie Zhang Guoqing Zhang Guanghui Fan 《International Journal of Applied Ceramic Technology》2022,19(4):2276-2284
Coated tools are currently widely used tool technology in machining. The influence of tool coating on heat transfer has become an active field of research enjoying constantly increasing attention in the field of machining. This paper is devoted to the cutting temperature in machining H13 hardened steel with monolayer coated tools (TiN, TiAlN, and Al2O3) and multilayer coated tools (TiN/TiC/TiN and TiAlN/TiN). Equivalent composite thermal conductivity and thermal diffusivity of multilayer coated tools were calculated using the equivalent approach. The established heat transfer analytical models estimated coating temperature in turning. The effect of tool coating in steady and transient heat transfer was studied, as well as the cutting temperature distribution. It reveals that the tool coating material and coating thickness can influence the cutting temperature distribution of coated tool. Thermal conductivity of coating material affects the steady cutting temperature distribution, and thermal diffusivity of coating material affects the transient cutting temperature distribution of coating tools. 相似文献
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《Ceramics International》2020,46(8):11889-11897
The present work examines the applicability of DLC and WC/C low friction coatings on Al2O3/TiCN based mixed ceramic cutting tools for the dry and hard turning of AISI 52100 steel (62 HRC). The characterization of coated tools reveals that the coatings retain very low values of surface roughness, whereas the DLC coating exhibits much higher microhardness when compared to the WC/C coating. On the other hand, the WC/C coating exhibit a coarse surface morphology virtually due to the tungsten doping. Later, continuous turning tests were executed with the help of coated and uncoated cutting tools under dry cutting conditions, and their performance was investigated in terms of machining forces, cutting temperature and tool wear. Coating delamination by flaking and peeling is quite prominent in the case of both the coatings; however, it is less severe for the WC/C coated tool. The coatings help to reduce machining forces, cutting temperatures and tool wear, but the performance of coated tools converge towards uncoated tool as the cutting speed, and feed rate is increased. Both the coatings prevent the development of cracks near the cutting edge with WC/C coating exhibiting superior wear behavior basically due to its multilayered structure and better thermal stability. Moreover, the tested low friction coatings don't serve as thermal barriers and only the lubrication generated due to graphitization at the chip-tool interface is mostly responsible for the improved machining performance. 相似文献
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由于切削过程中产生高温、刀具粘结与氧化严重,钛合金切削尤其是干切削,一直是刀具行业的重大挑战之一,而在刀具表面添加涂层是提高钛合金切削刀具寿命的有效途径。利用脉冲磁控溅射技术制备了TiB2涂层刀具,以相同基体的无涂层刀具为对照,干铣削Ti-6Al-4V钛合金,切削速度从30~100 m/min变化,研究TiB2涂层刀具的切削性能与失效机理。所制备的TiB2涂层具有(100)择优取向的六方晶体结构,组织致密。涂层硬度可高达4000 HV。切削实验发现,在30 m/min的低速时,TiB2涂层刀具的切削寿命超过无涂层刀具57%之多,当切削速度加倍到60 m/min时,刀具寿命未见下降。当切削速度增加到100 m/min时,TiB2涂层刀具与无涂层刀具切削寿命相当。TiB2涂层刀具表面氧化所产生的B2O3液化膜,起自润滑作用,可充分减少钛合金的粘结,降低摩擦力。因此,在TiB2或B2O3消失之前,TiB2涂层刀具均有良好表现。在100 m/min时,切削高温造成B2O3强烈挥发,且TiB2被氧化为多孔疏松的TiO2,刀具寿命急剧下降到无涂层刀具的水平。 相似文献
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This paper reports on a research project that studies the effect of particle size on the coating efficiency and coating uniformity in a powder coating system using the computational fluid dynamics as a modelling tool. The numerical simulations are conducted for different particle sizes with different distances between the spray gun and the coating part and different positions of the powder spray gun pattern adjuster sleeve (PAS). This study can provide detailed information on air flow pattern and particle trajectories inside the powder coating booth, and the coating film thickness on the coated part as well as the particle transfer efficiency (PTE). In numerical simulations, the air flow field is obtained by solving three‐dimensional Navier‐Stokes equations with standard κ‐ϵ turbulence model and non‐equilibrium wall function. The second phase, the coating powder, consists of spherical particles that are dispersed in the continuous phase, the air. In addition to solving transport equations for the air, the trajectories of the particles are calculated by solving the particle motion equations using the Lagrangian method. It is assumed that particle‐particle interaction can be neglected. The electrostatic field is modelled by solving the Laplace equation. 相似文献
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以环氧树脂和聚酰胺为基料,通过添加KH 560改性的纳米SiO2、SiC微粉、滑石粉和颜料等物质制备了一种适合用于碳纤维复合材料板材涂装的环氧涂料,探讨了聚酰胺与环氧树脂的质量比及改性纳米SiO2、SiC、滑石粉的添加量对漆膜性能的影响。结果表明:涂料的最佳配方以甲、乙组分总质量计为:聚酰胺与环氧树脂质量比为1∶3,改性纳米SiO2、SiC微粉、滑石粉填入量分别为1%、6%、8%,按此配方得到的环氧涂料涂覆在活化液处理后的碳纤维板材上,漆膜具有很好的耐酸碱性、耐水性和耐盐雾性,且柔韧性较好,高温处理后漆膜不发生起皱、脱皮等现象,达到了中车涂装的技术标准;环氧涂料和碳纤维板材存在物理和化学等相互作用,且环氧分子聚合过程中产生的内应力较小,因此附着性能优良,适合工业化作业。 相似文献
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锰基化合物具备高容量、高能量密度和高工作电压等特性,是水系锌离子电池(AZIBs)商业应用过程中的首选正极材料。然而,材料存在的电导率低、锰溶解、静电斥力效应和结构稳定性差等缺点,严重阻碍其大规模应用。采用表面活性剂辅助溶剂热法成功合成了碳纳米管(CNT)包覆ZnMn2O4/Mn2O3(ZMO/MO)复合材料,并探究了CNT包覆量对材料电化学性能和动力学过程的影响。采用X射线衍射和扫描电子显微镜对材料的结构和形貌进行表征。与纯相ZMO/MO相比,经CNT包覆的正极在0.1 A g-1电流密度下具有良好的循环稳定性和更高的倍率性能。并用循环伏安曲线和电化学阻抗探究了电极的动力学特性,两相复合提高了Zn2 扩散速率,CNT的包覆改善了材料的电荷传递。 相似文献
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以吲哚啉螺苯并吡喃(indoline spiropyrans,SP)和SrAl2O4:(Eu2+,Dy3+)(SAO-ED)发光粉为原料,采用界面配位键合方法在SAO-ED发光粉的表面包覆SP制备了SP/SAO-ED复合发光粉。通过X射线衍射、X射线光电子能谱、Fourier红外光谱表征了SP/SAO-ED复合发光粉的晶体结构和表面涂层组成;用紫外光谱、激发和发射光谱分析了该复合发光粉的光致发光性能和光致变色性能。结果表明:SP/SAO-ED复合发光粉由SAO-ED表面的金属离子与SP杂环上的N原子配位结合而成;该复合发光粉不但具有SAO-ED发光粉的晶体结构和光致发光性能,还具有SP的光致变色性能。 相似文献