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1.
《Ceramics International》2017,43(14):10817-10823
The addition effect of different ceramic particles such as TiB2, TiN and nano-Si3N4 on the microstructure and mechanical properties of TiCN-WC-Co-Cr3C2 based cermets, which are prepared by spark plasma sintering, was studied. Microstructural characterization of the cermets was done by scanning electron microscope. X-ray diffraction was performed to study the crystal structures. Mechanical properties such as hardness and fracture toughness were measured for the different developed cermets. The hardness and fracture toughness of the TiCN-WC-Co-Cr3C2 cermets without TiN, TiB2, and nano-Si3N4 were 8.4 GPa and 3.4 MPa m1/2, respectively. It was found that 5 wt% TiB2 addition alone improved the corresponding hardness and fracture toughness to 19.2 GPa and 6.9 MPa m1/2, respectively. The addition of 5 wt% TiN, improved the hardness and fracture toughness to 16.7 GPa and 6.9 MPa m1/2, respectively. With the combination of 5 wt% TiN and 5 wt% TiB2, the hardness and fracture toughness were improved to 15.5 GPa and 6.6 MPa m1/2, respectively. But, the addition of 5 wt% Si3N4 showed a balanced improvement in both hardness (17.6 GPa) and toughness (6.9 MPa m1/2). Fracture toughness did not change much for all the above cermets with different ceramic inclusions. 相似文献
2.
Yuxue Wu Huiwen Xiong Xueping Gan Zhiyou Li Kechao Zhou 《International Journal of Applied Ceramic Technology》2019,16(3):1184-1192
TiN-based cermets with different Cr3C2 addition were prepared by conventional vacuum sintering. Effect of Cr3C2 on microstructure and properties of TiN-based cermets were discussed. Owing to the formation of sound rims on TiN cores, ultrafine TiN-based cermets with more uniform microstructure and finer grains were obtained with 1 wt% Cr3C2. When the added Cr3C2 content enhanced from 0 to 2 wt%, the transverse rupture strength (TRS) and fracture toughness increased firstly and then decreased, while the hardness increased monotonically. For the experimental conditions considered, the cermet with 1 wt% Cr3C2 addition had optimal combination of hardness (91HRA), fracture toughness (14.7 MPa m1/2) and TRS (2123 MPa). 相似文献
3.
Dan Xie Huiwen Xiong Yuxue Wu Xueping Gan Zhiyou Li Kechao Zhou 《International Journal of Applied Ceramic Technology》2021,18(3):781-791
To solve the poor sinterability and wettability between TiN ceramic and pure metal via using coated composite powders, dense TiN-Ni cermets with uniform microstructure and fine grains were developed at a low sintering temperature of 1300℃ in this work. TiN powders were firstly activated in a strong acid solution, in order to achieve a step-like surface; Ni-coated TiN powders showed an uniform and controllable morphology. Two types of TiN-Ni cermets based on conventional milled powders and Ni-coated TiN composite powders were fabricated by spark plasma sintering (SPS), and used for the comparison concerning the sintering behavior, microstructure and related mechanical properties. Results showed that Ni-coated TiN composite powders helped to improve the sinterability between ceramic and metal, which is rather beneficial to obtain dense TiN-Ni cermets with homogeneous microstructure and high mechanical properties. Compared to those of conventional TiN-Ni, the relative density, Rockwell hardness and fracture toughness increased from 84.9% to 96.6%, 80.2 to 84.3, and 10.2 MPa·m1/2 to 14.7 MPa·m1/2, with a rather low sintering temperature of 1300 ℃, respectively. 相似文献
4.
Influence of molybdenum addition on the microstructure and mechanical properties of TiC-based cermets with nano-TiN modification 总被引:11,自引:0,他引:11
Ning Liu Yudong Xu Zhenhong Li Minghai Chen Guanghai Li Lide Zhang 《Ceramics International》2003,29(8):919-925
Effect of Mo addition on the microstructure and mechanical properties of TiC–TiN(nm)–WC–Co–Ni–C system cermets was studied in the work. Specimens were fabricated by conventional powder metallurgy techniques. The microstructure was investigated using transmission electron microscope (TEM) and the scanning electron microscope (SEM). Chemical compositions of different phases such as ceramic phase with core/rim structure [the core being TiC and rim being (Ti,W,Mo)(C,N)] and metallic phase were analyzed quantitatively by EDX. Mechanical properties such as flexural strength, fracture toughness and hardness were also measured. Results show that flexural strength and fracture toughness have a trend to decline with increasing Mo addition, but the change of hardness is not apparent with the increase of Mo addition. Results also reveal that finer microstructure and thicker rim phase will be obtained with the increase of Mo addition. The optimal addition of Mo can be estimated to be 4 wt.% with respect to TiC–10TiN(nm)–15WC–5Co–Mo–5Ni–1C system cermets. Fracture micrographs show that main failure mode of the cermets is a mixed one, i.e., trans-granular and inter-granular fractures both exist. 相似文献
5.
《Ceramics International》2023,49(12):20127-20137
In recent years, NbC–Ni cermets has been proposed as a potential substitute for WC-Co cemented carbide in machining and other fields because of its economy and good performance, which has attracted extensive attention of scholars. Research on improving its mechanical properties will help to explore its application potential. Graphene-reinforced NbC–Ni cermets were prepared using a microwave sintering technique, and the effects of multilayer graphene (MLG) on its mechanical properties and microstructure were investigated. The experimental results show that the addition of a certain content of graphene contributes to the densification of the material and inhibits the grain growth. The Vickers hardness, toughness, and bending strength increased and then decreased with an increase in the MLG content. When 0.75 wt% MLG was added, the comprehensive mechanical properties of NbC–Ni cermets were optimal, with a Vickers hardness, fracture toughness, and bending strength of 1297.5 kg/mm2, 18.23 MPa m1/2, and 1464.5 MPa, respectively, which were 12.01%, 38.95%, and 18.97% higher than those without MLG. At low MLG content, the graphene sheet layers were well dispersed in the matrix grain boundaries, whereas graphene agglomerates and pores appeared in cermets with 1 wt% MLG, which degraded their mechanical properties. The strengthening and toughening mechanisms of MLG include grain refinement, large-angle deflection of cracks, crack bridging, and pullout of graphene sheet layers. 相似文献
6.
Haojun Zhou Hongliang Tao Mingchu Huang Hao Yang Ning Wu Yimin Li Yuhang Yin Fenghua Luo 《Ceramics International》2021,47(2):2294-2302
This study explored the effect of diamond content (0, 0.3, 0.6, and 0.9 wt%) onTi(C0.5,N0.5)-based cermets prepared via vacuum sintering with respect to their final mechanical properties and microstructures, characterized using X-ray diffractionand scanning electron microscopy. After liquid phase sintering, all cermets exhibited a ‘black core/grey rim'and partial ‘white core/grey rim'structure. The cermet with 0.6 wt% diamond exhibited optimal mechanical properties with a Vickers hardness of 1795 ± 32 H V, transverse rupture strength of 2026 ± 45 MPa, and plane strain fracture toughness of 12.95 ± 0.3 MPa m1/2. This is due to grain refinement and the uniformly distributed ‘white core/grey rim'grains. During the incipient liquid formation stage,a higher carbon activity arising due to diamond graphitization may shift the equilibrium towards the product, thereby yielding additional white cores due to the consumption of heavy elements in the binder. Excessive diamond introduction inhibited the dissolution of Ti(C0.5,N0.5) into the binder, resulting in fewer white cores. 相似文献
7.
Two series of Ti (C, N)-based cermets, one with TiC addition and the other with TiN addition, were fabricated by conventional powder metallurgy technique. The initial powder particle size of the main hard phase components (Ti (C, N), TiC and TiN) was nano/submicron-sized, in order to achieve an ultra-fine grade final microstructure. The TiC and TiN addition can improve the mechanical properties of Ti (C, N)-based cermets to some degree. Ultra-fine grade Ti (C, N)-based cermets present a typical core/rim (black core and grayish rim) as well as a new kind of bright core and grayish rim structure. The average metallic constituent of this bright core is determined to be 62 at% Ti, 25 at% Mo, and 13 at% W by SEM–EDX. The bright core structure is believed to be formed during the solid state sintering stage, as extremely small Ti (C, N)/TiC/TiN particles are completely consumed by surrounding large WC and Mo2C particles. Low carbon activity in the binder phase will result in the formation (Ni2Mo2W)Cx intermetallic phase, and the presence of this phase plays a very important role in determining the mechanical properties of TiN addition cermets. 相似文献
8.
Xue Zhang Jin Du Guosheng Su Peirong Zhang Yujing Sun Chongyan Zhang Xiangmin Kong 《International Journal of Applied Ceramic Technology》2022,19(3):1354-1366
Mo2NiB2 is a kind of cermet with excellent mechanical properties, stable chemical properties, and excellent corrosion resistance and is often used in wear-resistant application fields, such as injection molding machine parts, can making tools and hot copper extruding dies. The brittleness of Mo2NiB2-based cermets limits their wide application. Mo2NiB2-based cermets were prepared by the vacuum sintering method, the effect of SiC whiskers (SiCw) on the microstructure and mechanical properties of cermets was investigated, and the toughening mechanism of SiCw on cermets was further discussed. The results indicate that with increasing SiCw content, the indentation fracture toughness (KIC), transverse fracture strength (TRS), and Vickers hardness (HV) of the cermets first increase and then decrease. The HV, TRS, and indentation fracture toughness of Mo2NiB2-based cermets with 0.5 wt% SiCw are 1 113 HV, 1 620 MPa, and 27.97 MPa·m1/2, respectively, which are 16.8%, 22.7%, and 25% higher than those without SiCw. In the sliding friction tests, Mo2NiB2-based cermets with 0.5 wt% SiCw have the smallest friction coefficient, low wear rate, and high wear resistance. SEM observation and analysis of the crack path and fracture surface showed that the toughening mechanism is whisker bridging, crack deflection, microcrack toughening, and whisker pull-out. The results indicate that the addition of 0.5 wt% SiCw can effectively improve the mechanical properties of Mo2NiB2-based cermets and further expand the application space of Mo2NiB2-based cermets. 相似文献
9.
《Ceramics International》2020,46(5):6300-6310
Metallic binder is a key factor affecting the microstructure and mechanical properties of Ti(C,N)-based cermets. To optimize the overall performances, cermets with various weight ratios of Ni/(Co + Ni) ranging from 0 to 1 were fabricated by gas pressure sintering. Microstructure, phase formation, interface structure and related mechanical properties of the sintered cermets were investigated. With the increase of the Ni/(Co + Ni) ratios, the black cores became smaller and grains of Ti(C,N) dispersed uniformly. Compared to the pure Ni or Co, Ni–Co binders accelerated the formation of rim phases, and avoided the nonuniform dispersed binder pools. When the ratio was 0.5, the cermets showed fine grains, uniformly dispersed binders and small lattice misfit of the core-rim interface, exhibiting the optimal mechanical properties, i.e. satisfactory Vickers hardness of 1670 (HV30) Kgf/mm2, bending strength of 1970 MPa and Fracture toughness of 8.94 MPa m0.5. This work sheds light on constructing the relationship between the microstructure, mechanical performance of Ti(C,N)-based cermets and the Ni/Co-based binders. 相似文献
10.
《Ceramics International》2021,47(21):30113-30128
To repair the surface defects of spline shaft and improve wear resistance, the coarse TiC reinforced Ni-based composite coatings were fabricated on the spline shaft surface by laser cladding with six types of precursors containing Ni45, coarse TiC, and fine TiN powder. The effects of ceramic content and fine TiN addition on the formability, microstructure, and mechanical properties of the coatings were studied comprehensively. In TiC reinforced Ni-based coatings 1–3 without fine TiN addition, the porosity decreased from 20.415 % to 0.571 % with the increase of TiC concentration. The coatings mainly consist of CrB, Cr7C3, Cr23C6, coarse TiC, and γ-Ni. With the addition of fine TiN, the length of the ceramic phases in coatings 1#–3# decreased slightly, while volume fraction and porosity increased. Moreover, the ring-shaped Ti (C, N) phases were also detected at the edges of both undissolved TiC and TiN particles, which improved the bonding force between ceramics and matrix. Besides, these ceramics inhibited the generation of columnar crystals and eliminated the heat-affected zone. The performance test results show that the coating 3# with 30 wt% TiC and 6 wt% TiN exhibits the best wear resistance despite slightly decreased hardness, and its friction coefficient of 0.409 and wear rate of 42.44 × 10−6 mm3 N−1·m−1 are, respectively, 0.667 and 0.307 times those of the substrate. Based on the additive/subtractive hybrid manufacturing technology, the optimized coatings were ground to obtain the finishing surface, which indicates that the coarse TiC reinforced coating can be employed in repairing the damaged parts. 相似文献
11.
Xiyue Kang Nan Lin Yuehui He Qiankun Zhang Meimei Zhang Yan Yan Yi Liu 《Ceramics International》2021,47(14):19934-19944
Ti(C,N)-WC-Mo2C-TaC-Co-Ni cermets with various content of La2O3 were prepared by gas-pressure sintering at 1450 °C. The effects of ultrafine La2O3 additions (0, 0.05, 0.1 and 0.2 wt%) on the microstructure, mechanical properties, wear resistance and cutting performance of cermets were explored. In the microstructure of cermets, the La2O3 particles and dissolved La element in binder phases were observed, which could inhibit the dissolution-precipitation process of ceramics phases during liquid-sintering. Furthermore, the La2O3 could absorb and react with the impurity Al element with low melting point from raw powders, avoiding the appearance of liquid phase at the low temperature and partial overheating during sintering process. These mechanisms could inhibit the abnormal growth of Ti(C,N) core-(Ti,W,Mo,Ta)(C,N) rim structures effectively, leading to the thinning of brittle rim phases and coarsening of wear-proof Ti(C,N) particles. The decrease of proportion of brittle rim phase and ultrafine Ti(C,N) particles promoted the fracture toughness. The increase of proportion and grain size of Ti(C,N) improved the hardness, wear resistance and cutting performance significantly. However, the excessive addition of La2O3 would result in the agglomeration of La2O3, causing the sharp decline of mechanical properties and cutting performance. The cermet with 0.1 wt% La2O3 addition possessed the optimal mechanical properties with Vickers hardness, transverse rupture strength and fracture toughness of 1710 (HV30) Kgf/mm2, 2480 MPa and 11.7 MPa m1/2, respectively. 相似文献
12.
Seyed Ali Delbari Behzad Nayebi Ehsan Ghasali Mohammadreza Shokouhimehr Mehdi Shahedi Asl 《Ceramics International》2019,45(3):3207-3216
In this research, we investigated the effects of SiC and multi-walled carbon nanotube (MWCNTs) addition on the densification and microstructure of titanium nitride (TiN) ceramics. Four samples including monolithic TiN, TiN-5?wt% MWCNTs, TiN-20?vol% SiC and TiN-20?vol% SiC-5?wt% MWCNTs were prepared by spark plasma sintering at 1900?°C for 7?min under 40?MPa pressure. X-ray powder diffraction patterns and scanning electron microscope (SEM) micrographs of the prepared ceramics showed that no new phase was formed during the sintering process. The highest calculated relative density was related to the TiN ceramic doped with 20?vol% SiC, while the sample doped with 5?wt% MWCNTs presented the lowest density. In addition, the SEM investigations revealed that the addition of sintering aids e.g. SiC and MWCNTs leads to a finer microstructure ceramic. These additives generally remain within the spaces among the TiN particles and prohibit extensive grain growth in the fabricated ceramics. 相似文献
13.
《Ceramics International》2016,42(4):5291-5298
The effect of WC content on microstructure and mechanical properties of the TiC–Ni3Al system cermets was investigated. Ni3Al-bonded cermets showed a core–rim structure with carbide particle coupled with rim embedded in Ni3Al binder. With WC content increasing, TiC grains were refined and the white rim became complete and got thicker gradually. Interface between core and rim showed a completely coherent relationship. The rim enriched in W constituted an ideal coherence between hard phase and Ni3Al binder phase. With WC content increasing, the densification of cermets was enhanced, and hardness and TRS were increased firstly and then reduced, reaching peak values 90.9 HRA (HV30 15 GPa) and 1629 MPa, respectively in cermet N5 (25 wt% WC). Similarly, fracture toughness got a peak value (11.6 MPa m1/2), at the composition with 20 wt% WC. 相似文献
14.
Shi‐Kuan Sun Ji‐Xuan Liu Ji Zou De‐Wei Ni 《Journal of the American Ceramic Society》2013,96(3):867-872
Hafnium carbide/tungsten (HfC/W) cermets were prepared by an in situ reaction sintering process, using hafnium oxide (HfO2) and tungsten carbide (WC) as the raw materials. The reaction path, densification behavior, microstructure development, and mechanical properties of the cermets were comprehensively investigated. It was found that WC decomposed to tungsten semicarbide (W2C) and tungsten (W) in sequence, and meanwhile HfC was formed by carbothermal reduction between HfO2 and as‐released carbon from the dissociation of WC. The solid solution formation between HfC and W during sintering was also studied. The obtained cermets (>98% TD) have a Vickers' hardness of 8.16 GPa, a fracture toughness of 14.45 MPa m1/2, and a high flexural strength of 1211 MPa. 相似文献
15.
In this study, Ti(C,N)-WC-NbC-ZrC-Co-Ni cermets were prepared by sintering-hip at 1450?°C. The effect of ZrC addition on the microstructure, mechanical properties, oxidation resistance and wear resistance of Ti(C,N)-WC-NbC-Co-Ni cermets were explored in detail. The results show that ZrC addition plays the role of inhibitor in the dissolution–reprecipitation process, which can increase the wear-resistant carbide phases and inhibit the precipitation of brittle (Ti,W,Nb)(C,N) rim phase. Therefore, the core-rim structures are refined and the Nb content in binder increases, which enhance mechanical properties and oxidation resistance of cermets. With the increasing ZrC content, the oxidation resistance of cermets can be improved constantly, while the transverse rupture strength, fracture toughness and wear resistance of these cermets increase first and then decrease. The cermet with 1?wt% ZrC exhibits the transverse rupture strength of 2549?MPa and highest fracture toughness of 13.0?MPa?m1/2. The oxidation weight gain of cermets containing 5?wt% ZrC after holding 100?h at 750?°C in air is 2.8?×?10?6 g?mm?2, which is only 22% of that in the cermets without ZrC addition. 相似文献
16.
《Journal of the European Ceramic Society》2014,34(3):621-632
In this study, cermets composed of zirconium diboride and zirconium carbide with intergranular zirconium were sintered by reactive hot-pressing. Relative density exceeding 97% was obtained for the sintered cermets having four distinct compositions varying in concentration of excess Zr. Their densification behaviour was examined by monitoring displacement during sintering. The microstructure was characterized by scanning electron microscopy and X-ray diffraction, and the elastic and mechanical properties were evaluated at room temperature. The effects of Zr concentration on the densification and mechanical properties were assessed. The ZrB2 and ZrC micron-grains coarsened with increasing amount of Zr starting material. In addition, the cermets exhibited high flexural strength (546–890 MPa) and fracture toughness (6.63–10.24 MPa m1/2), which simultaneously increased with increasing Zr concentration. However, the elastic moduli and hardness (11–18 GPa) decreased with increasing Zr. The shear modulus and Young's modulus were in the range of 150–190 GPa and 360–440 GPa, respectively. 相似文献
17.
《应用陶瓷进展》2013,112(5):247-254
AbstractEffect of the particle size of TiC and TiN on the microstructure and mechanical properties of Ti(C,N) based cermets has been evaluated. Ti(C,N)–WC–Co cermets made from four groups of mixed raw powders of different sizes were manufactured by vacuum sintering. The microstructure and composition were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectrum (EDX). The result shows that the four samples have the typical microstructures of 'black core/grey rim'. The mechanical properties of the cermet manufactured from submicron TiC and nano TiN are the best among the four samples. 相似文献
18.
The effects of TiN and nano-TiB2 additions to titanium carbonitride (TiCN-WC-Cr3C2-Co)-based cermets processed by spark plasma sintering (SPS) are identified. The TiN and nano-TiB2 additions were varied from 0 to 15?wt% to ascertain their combined effects on the mechanical properties. Scanning electron microscopy (SEM) revealed the combined chemical composition of the new phases formed during sintering. The hardness and fracture toughness values were recorded. Increase in the fracture toughness value with TiN addition was more compared with the nano-TiB2 addition. In contrast, the hardness values were higher for the cermets formed with the nano-TiB2 addition. Sintered bodies were made as tool inserts that meet SNGN120408 standard tool configuration. Using these tools, EN24 work-piece was turned at different cutting speeds of 11.87, 29.68, 71.46, 163.88?m/min under conditions of dry cutting. The performance was evaluated. Cutting force as well as surface roughness of the work-piece after machining was measured. For all cutting tools, initially the cutting force was high but it tended to decrease at higher cutting speeds. In addition, for all the tools, at higher cutting tools the surface roughness values were uniformly minimal. The cermet with a composition 55TiCN-15WC-10Co-5Cr3C2–15nanoTiB2 (all in wt%), in particular, showed a balanced enhancement in both fracture toughness (6.8?MPa?m1/2) and Vickers hardness (18?GPa) values. The surface finish of the work-piece was also the best after machining when a tool of the above composition was used. 相似文献
19.
Özgür Sevgi Canarslan Levent Koroglu Erhan Ayas Necip Suat Canarslan Alpagut Kara Paolo Veronesi 《Ceramics International》2021,47(1):828-835
In the present study, 17 wt % TiN reinforced α-β SiAlON composites were sintered at low temperature by susceptor-assisted microwave heating. The effect of TiN addition on dielectrical properties of starting powders, as well as the influence of sintering temperature on phase evolution, microstructure development and mechanical properties of α/β-SiAlON-TiN composites were investigated. The obtained results showed that TiN addition increased the microwave absorbing properties which is reflected in the peak sintering temperature. Thus, the α:β ratio decreased and mechanical properties were improved, especially the fracture toughness of the composites. Furthermore, an estimate of energy consumption during microwave assisted sintering at the laboratory scale is presented. As a result, the highest values for relative density (97.1%), Vickers hardness (13.35 ± 0.47 GPa), and fracture toughness (7.52 ± 0.54 MPa m1/2) were obtained by microwave sintering for 30 min at 1300 °C. 相似文献
20.
Lei He Hongtao Yu Mengshi Zeng Ting Luo Jingsong Liu 《Journal of the American Ceramic Society》2018,101(11):5110-5119
0.73ZrTi2O6–0.27MgNb2O6 ceramics with various Al2O3 contents (0‐2.0 wt%) were prepared by conventional ceramic route. The effects of Al2O3 on the phase composition, microstructure, conductivity, and microwave dielectric properties were systematically investigated. The coexistence of a disordered α–PbO2‐type phase and a rutile second phase was found in all compact ceramics with low Al2O3 contents (x = 0, 0.5, and 1.0 wt%), while a corundum phase was detected when Al2O3 additive increased to 1.5 and 2.0 wt% based on X‐ray diffraction results. With the addition of Al2O3, the decreased grain size of the matrix phase was observed using field‐emission scanning electron microscope, accompanied with increased resistivity and band‐gap energy. Additionally, Al2O3 additives efficiently improved the quality factor of the ceramics. After sintering at 1360°C for 3 hours, the ceramic with 1.0 wt% Al2O3 exhibited excellent microwave dielectric properties: a dielectric constant of 43.8, a quality factor of 33 900 GHz (at 6.6 GHz), and a near‐zero temperature coefficient of resonant frequency (3.1 ppm/°C). 相似文献