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1.
《Wear》2006,260(7-8):699-704
The microstructure and wear behavior of WC–8TiC–3TaC–8Co cemented carbide and CuZnNi alloy composite strengthening materials have been investigated by means of scanning electron microscopy (SEM), electron dispersion X-ray analysis (EDAX) and wear test. Effect of applied load and sliding distance on the wear behavior of the strengthening materials are also studied in this paper. The results show that the cemented carbide particles are surrounded by the α + β phases in the hardfacing layers. There exists an inter-diffusion zone at the interface of the cemented carbides and Cu-based matrix due to the mutual diffusion of elements. The wear volume of both the WC–8TiC–3TaC–8Co/CuZnNi and WC–8Co/CuZnNi composite strengthening layers increased with the increasing of applied load. The WC–8TiC–3TaC–8Co/CuZnNi hardfacing layers exhibited lower wear volume loss than that of WC–8Co/CuZnNi. According to the results of engineering application, the working efficiency and employing life of the milling shoes, which were strengthened by WC–8TiC–3TaC–8Co/CuZnNi composite materials, is by approximately two to three times the milling tools strengthened by WC–8Co/CuZnNi. 相似文献
2.
《Wear》2006,260(7-8):815-824
The friction and wear behaviour of cermets/steel rubbing pairs were investigated. Friction and wear tests were carried out using three different crèmets on the base of tungsten, titanium and chromium carbides under dry sliding conditions against steel disk (0.45% C). Sliding wear tests were carried out using modified block-on-ring equipment at a sliding speed of 2.2 m/s and normal load 40 N.It is shown that wear resistance and coefficient of friction depend on the type and chemical composition of the cermets. The WC–Co cermets have the highest wear resistance. The wear rate of WC–Co and TiC–NiMo cermets increased with increasing binder content in the cermets. The wear of Cr3C2–Ni cermets is more complicated and depends on the composition of cermets. The wear of WC–Co cermets is caused mainly by preferential removal of the cobalt binder, followed by fracture of the intergranular boundaries and fragmentation of the carbide grains. The main wear mechanism in the TiC–NiMo cermets is polishing (micro-abrasion) and adhesion, resulting in a low wear rate. The main wear mechanism of Cr3C2–Ni cermets involves thermal cracking and fatigue-related crushing of large carbide grains and carbide framework and also adhesion. 相似文献
3.
《Wear》1996,193(1):16-24
Wear surfaces of the cutting tools are analyzed to study the wear mechanism of cemented carbide tools in turning in Inconel 718 superalloys. SEM and EPMA analyses indicated that the wear of carbide tools during high speed turning condition (V = 35 m min−1) was caused by diffusion of elements (Ni or Fe) in workpiece into tool's binder (Co) by a grain boundary diffusion mechanism. This action weakened the bonding strength between carbide particles (WC, TiC, TaC) and the binder (Co). The carbide particles were then detached out of the cemented carbide tool by high flow stresses. The proposed grain boundary diffusion mechanism is also confirmed by theoretical analysis. 相似文献
4.
Simul Banerjee Debasish Mahapatro Shishir Dubey 《The International Journal of Advanced Manufacturing Technology》2009,43(11-12):1177-1188
Electrical discharge machining process is a potential method of shaping ({WC+TiC+TaC/NbC}–Co) cemented carbide known for its superior hardness and compressive strength at high temperature and resistance to diffusion wear. Yet, detailed study on electrical discharge machining of this material is lacking in the literature. In the present investigation, therefore, mathematical models are developed for material removal rate, wear ratio, and surface roughness in electrical discharge machining of this cemented carbide using the procedure of statistical design of experiments. Current setting, pulse on time, and pulse off time are chosen as input parameters. Based on available machine settings, a face-centered central composite design is selected for meaningful experimentations. The procedure may be extended to develop a data bank for such type of materials. Further, to reveal the attributes behind the removal of material from the work-piece surface, scanning electron micrographs are studied. It appears that sufficient superheating of work-piece material and subsurface boiling is essential for efficient material removal and that formation of pock marks due to burst of blisters and associated crack formation may be controlled by choosing a proper dielectric. 相似文献
5.
针对航空航天钛合金加工时硬质合金刀具磨损过快的难题,制备了主元素一致、微量合金碳化物TaC(NbC)含量不同的两种WC-Co基硬质合金材料。采用高温维氏硬度计检测两种材料的高温硬度和高温断裂韧性,并制备相同几何参数的立铣刀对钛合金TC4进行铣削加工试验。试验结果表明:在硬质合金中添加微量合金碳化物TaC(NbC),可以同时提高材料的高温硬度和高温断裂韧性,在相同的切削条件下,添加微量合金碳化物TaC(NbC)的硬质合金立铣刀比未添加微量合金碳化物的立铣刀耐磨性更好,刃口断裂裂纹更少,刀具使用寿命更长,更适合航空航天钛合金材料的高速铣削加工。 相似文献
6.
WC cemented carbides are used extensively to improve abrasion resistance. Co content and WC grain size influence the mechanical properties of the cemented carbides. In this study, the effects of Co content and WC grain size of cemented carbide on wear were examined. We prepared 13 different cemented carbides with different Co content and WC grain size. Wear tests were carried out against 0.45% carbon steel under dry condition at 98 N and 232 mm/s. From the results, we found that wear increased with both Co content and WC grain size. Specific wear rate of the cemented carbides tested was in the range of 10−7 mm3/(N m). We discussed the wear properties with hardness and the mean free path of the cemented carbide. These two parameters alone cannot explain the wear property. 相似文献
7.
A binderless cemented carbide has been evaluated in abrasion and erosion tests. The binderless carbide was compared with:
SiC, Al2O3 and two conventional cemented carbides with 6% Co and different WC grain sizes (1 and 7 μm). In the abrasion tests, the materials
were ground with silica, silicon carbide and diamond particles in the size range of 5–15 μm. The erosion tests were performed
with 80, 200 and 600 μm silicon carbide erodents. The angle of impingement was 45° and the erodent velocity 70 m/s. In all
tests, the conventional cemented carbides showed the highest, the binderless cemented carbide an intermediate and the ceramics
the lowest wear resistance. Scanning electron and atomic force microscopy of the abraded surfaces revealed that the binderless
cemented carbide was worn by a preferential removal of TiC grains. In erosion, the wear mechanism was largely plastic for
the cemented carbides, whereas the ceramics were worn by micro-fracture. The SEM analysis also showed an impact scaling effect
for the cemented carbides in erosion.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
8.
为了改善硬质合金刀具切削加工钛合金的摩擦磨损性能,从而减少钛合金加工中浓缩乳化切削液的用量,利用脉冲磁场对WC-6Co硬质合金进行强化处理,在不同配比切削液润滑下研究磁场处理对WC-6Co/钛合金的摩擦行为的影响。结果表明:磁场处理大幅提高了WC-6Co/钛合金的摩擦性能,且随着浓缩乳化切削液与水配比的降低,摩擦因数明显降低;脉冲磁场处理后,WC-6Co硬质合金/钛合金摩擦后的表面得到强化,黏结相Co的脱落减少。磁场处理后硬质合金磨损性能的改善,是脉冲磁场作用下Co相磁致伸缩对硬质合金的强化效果以及硬质合金剩磁对切削液中油滴吸附的耦合结果。 相似文献
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E. E. Ashkinazi V. S. Sedov M. I. Petrzhik D. N. Sovyk A. A. Khomich V. G. Ralchenko D. V. Vinogradov P. A. Tsygankov I. N. Ushakova A. V. Khomich 《Journal of Friction and Wear》2017,38(3):252-258
Micro- and nanocrystalline uniform diamond coatings with barrier tungsten layers for improved adhesion were deposited in a microwave plasma from methane-hydrogen mixtures on cemented carbide WC–6% Co substrates with high aspect ratios. Dynamic study of cutting forces and sliding friction has shown a significant improvement in the tribological properties of diamond-coated tools in cutting highly abrasive materials, such as A390 silumin and carbon-carbon composites. Confocal Raman spectrometry has been used to examine the features of wear mechanism in nano- and microcrystalline diamond coatings deposited in a microwave plasma. 相似文献
11.
S. N. Grigor’ev S. V. Fedorov M. D. Pavlov A. A. Okun’kova Ye Min So 《Journal of Friction and Wear》2013,34(1):14-18
The surface of the WC/Co carbide tool was modified by an electron beam with the magnetron sputtering of Nb + Hf + Ti alloy to obtain a gradient interlayer before hardfacing with (Ti + Al)N. The results of investigations of the composite using a scanning electron microscope equipped with a device for X-ray energy dispersion spectroscopy are given. The results of the comparative mechanical tests show reduced wear rate. 相似文献
12.
《Wear》2002,252(9-10):832-841
Steel matrix particulate composites were processed by direct addition of various powders to molten medium carbon steel. Fe–TiC and Fe–TiB2 powders were produced using a self-propagating high-temperature synthesis (SHS) reaction and consisted of a dispersion of fine TiC (5–10 μm) and TiB2 particles (2–5 μm), respectively in an iron binder.Addition of the Fe–TiC powder to the steel resulted in the formation of a metal matrix composite containing a homogeneous dispersion of TiC particles. However, addition of the Fe–TiB2 powder resulted in the formation of a parasitic Fe2B phase and TiC within the steel microstructure. In response to this an SHS masteralloy composed of Fe–(50% TiB2+50%Ti) was manufactured which, when added to steel, prevented the formation of Fe2B and resulted in a composite containing a mixture of TiB2 and TiC particles.Dry reciprocating sliding wear behaviour of the three composite materials and their unreinforced counterpart was investigated at room temperature against a white cast iron counterface. Relative wear behaviour of the materials varied as a function of load. In all cases, the composite manufactured by addition of Fe–TiB2 (yielding Fe2B and TiC phases in the steel) exhibited wear rates greater than three times that of the unreinforced alloy. However, improvements in wear resistance over the base steel of up to two and a half times were observed with the other composites where the desired TiC and/or TiB2 phases were retained in the steel. Scanning electron microscopy has been used to interpret wear behaviour in relation to both the as-cast microstructures of the composites and the wear scar microstructures observed. 相似文献
13.
《Tribology - Materials, Surfaces & Interfaces》2013,7(1):31-36
AbstractWC–Co cemented carbides, including small angular tungsten carbides particles, are used extensively to improve wear resistance. Some additives can affect mechanical and wear properties of these materials. In this study, the effect of VC and (Ta, Nb)C content on wear of WC–10Co were considered. The tests were performed at normal load of 230 N and sliding distance of 800 m up to 3200 m. Wear tests were carried out using dry sand/rubber wheel apparatus. Wear rate, standard and modified wear coefficients were calculated. The microstructures of prepared specimens were examined by optical microscopy. The morphological analysis of the worn surfaces was made by SEM. The results show that VC content has more effect than (Ta, Nb)C content on wear behaviour. Wear mechanism is different in the specimens, but removal of cobalt rich phase and fracture of carbide grains is clear in all of specimens. Abrasive wear is prevailing in all specimens. 相似文献
14.
The effect of 10 wt% VC addition on the friction and sliding wear response of WC–12 wt% Co cemented carbides produced by spark plasma sintering (SPS) was studied. The SPS of WC–12 wt% Co alloys with and without 10 wt% VC, at 1100 and 1130°C, respectively, yielded dense materials with minimal porosity. No eta phase was found in any of the alloys. The WC–12 wt% Co–10 wt% VC alloy showed the formation of a hard WV4C5 phase, which improved the alloy's hardness. Friction and dry sliding wear tests were done using a ball-on-disk configuration under an applied load of 10 N and sliding speed of 0.26 m.s?1, and a 100Cr-steel ball was used as the counterface. A significant improvement in the sliding wear response of the harder and more fracture tough WC–12 wt% Co–10 wt% VC alloy compared to the WC–12 wt% Co alloy was found. Analysis of the worn surfaces by scanning electron microscopy showed that the wear mechanisms included plastic deformation, preferential binder removal, adhesion, and carbide grain cracking and fragmentation. 相似文献
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本文对Al2O3/TiC陶瓷刀具材料切削加工G4335V高强钢时的切削性能和耐磨性进行了试验研究。结果表明:在低速切削条件下,Al2O3/TiC陶瓷刀具和硬质合金刀具(YT15)的抗后面磨损能力相差不大,而在高速切削条件下,前者的抗后面磨损能力远高于后者。Al2O3/TiC陶瓷刀具前面的磨损形式主要为粘结磨损,后面的磨损形式主要为磨粒磨损。 相似文献
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19.
G��l Tosun 《The International Journal of Advanced Manufacturing Technology》2011,52(5-8):477-485
Four micro-holes were made using micro-EDM on rake face of the cemented carbide (WC/TiC/Co) tools. MoS2, CaF2, and graphite solid lubricants were respectively embedded into the four micro-holes to form self-lubricated tools (SLT-1, SLT-2, and SLT-3). Dry machining tests on hardened steel were carried out with these self-lubricated tools and conventional tools (SLT-4). The cutting forces, average friction coefficient between tool and chip, and tool wear were measured and compared. It was shown that the cutting forces and tool wear of self-lubricated tools were clearly reduced compared with those of the SLT-4 conventional tool. The SLT-1 self-lubricated tool embedded with MoS2 just exhibited lower friction coefficient between tool and chip in cutting speed of less than 100?m/min; the SLT-2 self-lubricated tool embedded with CaF2 possessed lower friction coefficient in cutting speed of more than 100?m/min; and the SLT-3 self-lubricated tool embedded with graphite accomplished good lubricating behaviors steadily under the test conditions. It is indicated that cemented carbide inserts with four micro-holes on rake face embedded with appropriate solid lubricants on rake face is an effective way to reduce cutting forces and rake wear. 相似文献
20.
K. Bonny P. De Baets J. Vleugels A. Salehi O. Van der Biest B. Lauwers W. Liu 《Tribology Letters》2008,30(3):191-198
ZrO2-based composites with WC addition can be successfully machined by electrical discharge machining (EDM) in demineralised water.
ZrO2 composites with 40 vol.% WC were produced from nanocrystalline and micrometre sized WC starting powders in order to compare
their tribological behaviour. Friction and wear data are obtained on wire-EDM’ed ZrO2–WC composite flats sliding against a WC–Co cemented carbide pin using a small-scale pin-on-plate testing rig. Correlations
between wear volume, wear rate and friction coefficient on the one hand and material properties and test conditions on the
other hand were elucidated. The experimental results revealed that the grain size of the electro-conductive WC-phase exhibits
a strong influence on the friction and wear behaviour of the ZrO2-based composite. 相似文献