8 results on '"Ren, Haibo"'
Search Results
2. Fabrication and characterization of ultrafine WC-10CoCrNiCuFe cemented carbides.
- Author
-
Zou, Qin, Ren, Haibo, Li, Yanguo, Xiong, Jianchao, and Luo, Yongan
- Subjects
POWDERS ,FACE centered cubic structure ,MECHANICAL alloying ,VICKERS hardness ,TUNGSTEN carbide ,CARBIDES ,FRACTURE toughness - Abstract
• After ball milling, the average size of HEA powder composed of large particles and small particles is about 7.1 µm and 1 µm, respectively, and the average size of WC particles is about 368.5 nm. The microstructure consists of FCC phase, HCP-WC phase, Cr 2 O 3 and η(Fe,Co) 3 W 3 C phase. • The interface characteristics of the WC/HEA system include the FCC(111)//HCP (10 1 ‾ 1) interface with stable ionic bond and the interface that reacts due to the formation of (Fe, Co) 3 W 3 C phase. • The density, hardness and fracture toughness values of WC-10 wt% HEA cemented carbide are 14.38 g/cm
3 , 1988.60 HV, 10.98 MPa m1/2 , and the compressive strength values at room temperature and 800 ℃ are 3307 MPa and 1747 MPa, respectively. The thermal conductivities at 50 °C and 650 °C were 38 W(m K)−1 and 30.4 W(m K)−1 , respectively. The metal oxides generated by friction behavior at 500 °C have a good effect of reducing friction and antiwear, with an average friction coefficient of 0.365. A new ultra-fine tungsten carbide (WC) cemented carbide was fabricated by spark plasma sintering (SPS), in which the CoCrNiCuFe high entropy alloy (HEA) was used as the binder and was mixed with WC carbide through the mechanical ball milling method. The microstructure of WC-10 wt% HEA composites was investigated through scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and differential scanning calorimetry-thermogravimetric analysis (DSC-TG). The results show that the interface characteristics of the WC/HEA system include the FCC(111)//HCP (10 1 ¯ 1) interface with stable ionic bonds and the interface that reacts due to the formation of the (Fe, Co) 3 W 3 C phase. The mechanical properties of WC-10 wt% HEA composites were investigated through the Vickers hardness test, friction and wear tests, and compression test. The WC-10 wt% HEA composites exhibit good fracture toughness and hardness of 10.98 MPa m1/2 and 1988.60 HV 30 , respectively. The compressive strength at room temperature and 800 °C is up to 3307 and 1747 MPa, respectively. The composites exhibited excellent properties attributed to the good wettability of HEA on WC grains and the consequent strengthening effect on the WC/WC interfaces. [Display omitted] [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
3. Effect of CeO2 on Microstructure and Wear Property of Laser Cladding Ni-Based Coatings Fabricated on 35CrMoV Steel.
- Author
-
Gao, Zhongtang, Ren, Haibo, Geng, Haomin, Yu, Yuan, Gao, Zhiming, and Zhang, Chuanwei
- Subjects
MECHANICAL wear ,X-ray photoelectron spectroscopy ,MICROSTRUCTURE ,EUTECTIC structure ,MICROSCOPY - Abstract
The effects of CeO
2 addition on the macro-morphology, surface cracks, microstructure, precipitated phases and wear property of laser cladding Ni-based coatings on 35CrMoV steel were investigated by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscope (TEM), x-ray photoelectron spectroscopy (XPS) and friction and wear tester, respectively. The results indicated that the microstructure could be remarkably refined with the addition of CeO2 . The width of eutectic structure is reduced from 1.74 μm to 237.5 nm with the amount of CeO2 increases from 0 to 4.0 wt.%. Meanwhile, CeO2 significantly decreases the number of the oxides and it can be obtained the minimal number of cracks when the CeO2 addition reaches 4.0 wt.%. The main phase composition of Ni60 cladding layer is Ni3 Fe, Ni3 V, Cr23 C6 and Fe5 C2 . The distortional zone was observed around the eutectic of the coating. The average friction coefficient (0.438) and the wear resistance are the best when the addition of CeO2 is 4.0 wt.%. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
4. Controlled synthesis of porous Co3O4 micro/nanostructures and their photocatalysis property.
- Author
-
Huang, Jiarui, Ren, Haibo, Chen, Kaikai, and Shim, Jae-Jin
- Subjects
- *
POROUS materials synthesis , *COBALT compounds synthesis , *NANOSTRUCTURED materials synthesis , *PHOTOCATALYSIS , *X-ray diffraction - Abstract
Porous nanoflower-like, micropancake-like and microflower-like Co 3 O 4 micro/nanostructures were synthesized by a template-free aqueous solution route combined with subsequent thermal treatment. Techniques of X-ray diffraction, scanning electron microscopy, thermogravimetric-differential thermal analysis, and transmission electron microscopy were used to characterize the structure and morphology of the products. The experimental results show that three kinds of morphologies of cobalt precursors can be achieved by addition of ammonia at different temperatures. The corresponding Co 3 O 4 hierarchical micro/nanostructures were obtained after 500 °C calcinations. In addition, the obtained porous Co 3 O 4 hierarchical micro/nanostructures were used as catalyst to photodegrade Rhodamine B, methylene blue, p-nitrophenol, eosin B, and methyl orange. Compared with porous Co 3 O 4 micropancakes, the as-prepared porous Co 3 O 4 nanoflowers and microflowers exhibit higher catalytic activities due to their large surface areas and porous hierarchical structures. The photocatalytic reaction rate constant of the porous Co 3 O 4 nanoflowers in photocatalytic decomposition of Rhodamine B under UV light is calculated as 0.0828 min −1 . [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
5. Effect of CeO2 on the microstructure and microhardensss of laser-cladded Ni60 on 35CrMoV alloys.
- Author
-
Gao, Zhongtang, Ren, Haibo, Yuan, Yu, Gao, Zhiming, Liu, Eryong, and Zhang, Chuanwei
- Published
- 2021
- Full Text
- View/download PDF
6. Effects of TiC0.4 and Ti addition on the microstructures and mechanical properties of TiC composites.
- Author
-
Zou, Qin, Li, Zhuang, Li, Shuang, Ren, Haibo, Yin, Yuhui, Han, Bingxue, Li, Yanguo, and Luo, Yongan
- Subjects
- *
MICROSTRUCTURE , *TITANIUM carbide , *VICKERS hardness , *LATTICE constants , *FRACTURE toughness , *TITANIUM composites , *CERAMICS - Abstract
TiC-14 wt%TiC 0.4 and TiC-7.63 wt%Ti ceramics were fabricated by spark plasma sintering (SPS) at a sintering temperature of 1600 °C and an applied pressure of 40 MPa. The impact of ex-situ addition and in-situ formation of vacancies on the microstructures and mechanical properties of TiC composites were investigated. The microstructures were analysed by XRD, SEM, EDS and TEM. The results reveal that TiC 1-x phases with different Ti/C ratios exist in the TiC-14 wt%TiC 0.4 ceramics, which have the same crystal structure and similar lattice parameters. In contrast, only a single phase of TiC 1-y exists in the TiC-7.63 wt%Ti ceramics. The introduced carbon vacancies not only lowered the sintering temperature, but also had a toughening effect on the material. At a sintering temperature of 1600 °C, the TiC-14 wt%TiC 0.4 and TiC-7.63 wt%Ti materials had densities of 98.5% and 99.2%, both materials exhibited excellent mechanical properties Vickers hardness and fracture toughness of 22.5 GPa, 5.2 MPa m1/2 and 23.5 GPa, 4.9 MPa m1/2, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. The role of Cu element in Fe9.4Co6.7Ni6.6Mn0.9V0.9Cu2.4 magnetic high-entropy alloys.
- Author
-
Luo, Wenqi, Li, Yanguo, Zou, Qin, Dai, Lifeng, Ren, Haibo, Jia, He, and Luo, Yong'an
- Subjects
- *
MAGNETIC alloys , *FACE centered cubic structure , *COPPER , *MAGNETIC moments , *HIGH-entropy alloys , *MAGNETIC entropy - Abstract
Spark plasma sintering (SPS) technology has obvious advantages in the preparation of high entropy alloys (HEAs) with high mechanical properties, but the mechanism of their magnetic enhancement is not clear. In this work, HEAs with high saturation magnetization (Ms) and excellent mechanical properties were designed and prepared. The properties of Fe 9.4 Co 6.7 Ni 6.6 Mn 0.9 V 0.9 HEA were optimized by adding Cu element, and the main phase of the HEAs was (face-centered cubic) FCC phase. The addition of Cu element mitigates the distortion of the FCC phase, resulting in an increase in the intensity of Ms value for the alloy from 118 emu/g to 143.7 emu/g. However, this also leads to a slight reduction in yield strength while still maintaining a high level at 1132 MPa. Theoretical calculations based on first principles indicate that the magnetic enhancement of these alloys is facilitated by an increase in the atomic magnetic moments of their ferromagnetic constituents. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
8. The role of onion-like carbon addition on high pressure and high temperature sintered TiN0.3.
- Author
-
Zou, Qin, Yuan, Zhenxiong, Li, Yanguo, Ren, Yu, Dai, Lifeng, Ke, Yujiao, Ren, Haibo, and Luo, Yongan
- Subjects
- *
HIGH temperatures , *CARBON composites , *BINDING agents , *TITANIUM nitride , *VICKERS hardness - Abstract
The high melting point and the covalent bond between Ti and N made the titanium nitride matrix composites difficult to sinter using conventional sintering methods. TiN 0.3 and onion-like carbon (OLC) were used as starting materials for the preparation of TiN 0.3 /onion-like carbon composites under high pressure and high temperature (HTHP) of 5.0 GPa and 1100–1400 °C for 10 min. The phase formation, microstructure, and mechanical properties of TiN 0.3 composites with different contents of onion-like carbon were systematically investigated by XRD, SEM, and TEM. The experimental results showed that TiC 0.3 N 0.7 was formed by diffusion of TiN 0.3 with onion-like carbon due to the dual effect of high concentration of N vacancies and high pressure, and the onion-like carbon was gradually graphitized with increasing temperature. The composites of TiN 0.3 /5 vol% onion-like carbon sintered at 1200 °C possessed the optimum properties, with hardness of 15.2 GPa and fracture toughness of 3.9 MPa·m1/2. Compared with TiN composites prepared by conventional methods, the non-stoichiometric compound reduced the sintering temperature of the TiN composites. [Display omitted] • The OLC was used as a binding agent component. • The Vickers hardness of the sintered body was enhanced by the diamond. • A new method of forming TiC 0.3 N 0.7 by N vacancies in TiN 0.3 with OLC defects [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.