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oe1(光电查) - 科学论文

22 条数据
?? 中文(中国)
  • High Temperature Oxidation and Wear Resistance of In Situ Synthesized (Ti3Al?+?TiB)/Ti Composites by Laser Cladding

    摘要: (Ti3Al + TiB)/Ti composites were prepared on Ti6Al4V by laser cladding. The microstructures of the coatings were analyzed; the high temperature wear and oxidation properties of the coatings were investigated and compared with Ti6Al4V. Ti3Al and TiB particles were in situ formed through the reaction between Ti and AlB2. The reinforcements exhibited some crystallographic orientation relationships with a-Ti matrix, and a semi-coherent interface (Ti3Al) or a coherent interface (TiB) was obtained. The weight gain of the coating under each combination of temperature and time condition was 20 to 30 pct of the value of Ti6Al4V under the same experimental parameters. A denser and well-bonded TiO2 + Al2O3 layer was formed, effectively hindering the oxygen diffusion compared with the TiO2 layer on Ti6Al4V. EBSD result showed that the Al2O3 mainly assembled into clusters and located close to the interface while the outer area of the oxidation layer was mainly TiO2. The friction coefficients and wear losses of the coatings were lower than those of the substrates at 300 °C to 750 °C. The oxidation was a crucial factor affecting the wear performance at high temperatures. The protective effect of the TiO2 + Al2O3 layer and the formation of transfer films on the worn surface contributed to the improved wear resistance of the coating.

    关键词: TiB,Laser Cladding,Wear Resistance,Ti Composites,In Situ Synthesized,High Temperature Oxidation,Ti3Al

    更新于2025-11-28 14:24:20

  • Computational and Experimental Investigation of Micro-Hardness and Wear Resistance of Ni-Based Alloy and TiC Composite Coating Obtained by Laser Cladding

    摘要: The influence of processing parameters on the micro-hardness and wear resistance of a Ni-based alloy and titanium carbide (TiC) composite cladding layer was studied. Mathematical models were developed to predict the micro-hardness and wear resistance of the cladding layer by controlling the laser cladding processing parameters. Key processing parameters were the laser power, scanning speed, gas flow, and TiC powder ratio. The models were validated by analysis of variance and parameter optimization. Results show that the micro-hardness is positively correlated with laser power and TiC powder ratio, where the TiC powder ratio shows the most significant impact. The wear volume decreased with an increasing TiC powder ratio. The targets for the processing parameter optimization were set to 62 HRC for micro-hardness and a minimal volume wear. The difference between the model prediction value and experimental validation result for micro-hardness and wear volume were 1.87% and 6.33%, respectively. These models provide guidance to optimize the processing parameters to achieve a desired micro-hardness and maximize wear resistance in a composite cladding layer.

    关键词: Ni35A + TiC composite,laser cladding,central composite design,wear resistance,micro-hardness

    更新于2025-11-28 14:24:20

  • Microstructure and Wear Resistance of 62Cu-38Zn Brass with Bionic Coupling Units Treated by Laser Cladding

    摘要: In order to improve the wear resistance of 62Cu-38Zn brass, bionic coupling units were fabricated by laser cladding using Ni-based, Fe-based and Co-based self-fluxing alloy powders. The microstructures, chemical composition and mechanical properties of the units were studied in this paper. Wear resistance of samples was examined by dry sliding wear. Good metallurgical bonding between the unit and substrate was obtained, and fine dendritic microstructure was resulted in the unit zone, which proved marked availability of laser cladding on brass. Laser cladding treatments with different self-fluxing alloy powders were beneficial to reinforcing the surface of brass and then improved its wear resistance with various results. The Ni-based alloy powders led to the best wear resistance amongst the all samples.

    关键词: wear resistance,laser cladding,bionic coupling units,microstructure,62Cu-38Zn brass

    更新于2025-11-21 11:18:25

  • Effect of Nb addition on microstructure and properties of laser cladding NiCrBSi coatings

    摘要: NiCrBSi coatings with different Nb additions have been prepared by laser cladding. The microstructure, phase composition, hardness, and wear resistance of the coatings were studied by scanning electron microscopy (SEM), electron probe microanalyser (EPMA), X-ray diffraction (XRD), microhardness tester and M-200 wear tester. The results show that the phases in the NiCrBSi coating without Nb addition include γ-Ni, Cr23C6, Cr7C3, Ni3B, Ni3Si2 and CrB. The NbC phase appears in coatings after the addition of Nb element. When the addition of Nb is 2 wt-%, the NbC particles with a size of about 1.2 μm were found in the coating, and the amount of NbC is about 1.8 vol.-%. With the increase of Nb addition, the size and amount of NbC in the coatings also increased. When the addition of Nb is 6 wt-%, the size of NbC is about 2.3–6.1 μm and the morphology of NbC changed from particle to quadrangular and petaloid shaped. In addition, when the addition of Nb is 2 wt-%, the hardness and wear resistance of the coating are the best, and the wear resistance of the coating is 104% higher than that without Nb addition.

    关键词: Nb addition,wear resistance,microstructure,hardness,Laser cladding,NiCrBSi coatings

    更新于2025-09-23 15:21:21

  • Influence of Laser Energy Density on Acquisition and Wear Resistance of Bionic Semisolid Unit of 40Cr Steel

    摘要: 40Cr steel is one of the most common materials for manufacturing brake camshaft of trailer. The brake camshaft is subjected to extreme wear during its service life. In order to enhance wear resistance, medium frequency induction hardening (MFIH) treatment is usually conducted on the surface of brake camshaft. However, conventional MFIH technique requires heating of the entire surface, which has the drawbacks of more power consumption, high production cost and easy deformation. Therefore, inspired by the bionic theory, a process named as ‘‘laser bionic semisolid treatment’’ method accompanied by favorable surface roughness and minimum distortion has been proposed herein as an alternative to MFIH method. By this means, bionic units with different surface roughness, sizes microstructure and hardness were manufactured on the surface of 40Cr steel. Then, the wear resistance of 40Cr steel with various laser energy densities was experimentally investigated. The results demonstrated that when the laser energy density was 18:00t3 (cid:2)3 J/ mm2, the bionic semisolid unit was obtained with the arithmetic mean surface roughness Ra of 1046.81 nm. Moreover, in the wear resistance of 40Cr steel due to the microstructure and higher hardness compared with the untreated sample, and its weight loss ratio was decreased by 71.90%. The mechanism of wear resistance enhancement was also discussed.

    关键词: bionic semisolid unit,40Cr steel,wear resistance,laser energy density,surface roughness

    更新于2025-09-23 15:21:01

  • [IEEE 2019 International Conference on Engineering, Science, and Industrial Applications (ICESI) - Tokyo, Japan (2019.8.22-2019.8.24)] 2019 International Conference on Engineering, Science, and Industrial Applications (ICESI) - Wear Resistance Behaviour of Laser Additive Manufacture Materials: An Overview

    摘要: Laser additive manufacturing technology is an exciting technology which is based on powder metallurgy and laser technologies that has come to revolutionize the way important product are designed and produced. This manufacturing technology has a number of advantages over the traditional manufacturing processes which include: ability to reduce weight of product and with improved functionality, ability to manufacture part as a composite material and with high complexity in a single manufacturing process. Some of additive manufacturing process can also be used to repair high valued part. Apart these advantages, additive manufacturing technologies have been shown to have a high impact on the resulting properties of the manufactured materials which include the wear resistance behaviour. This paper presents an overview of the wear resistance behaviour of additive manufacture materials. The various classes of additive manufacturing technology are analyzed and presented. This study revealed that the wear resistance property of materials processed using additive manufacturing technologies can be improved by adjusting the processing parameters. Also the rapid cooling that is associated with this manufacturing process has a great influence in improving the wear resistance performance of the processed materials.

    关键词: wear resistance,Laser additive manufacturing,processing parameters,rapid cooling,additive manufacture materials

    更新于2025-09-19 17:13:59

  • The Increasing of the Operational Stability of Wood-Working tools by the laser cementation

    摘要: The paper describes the technology of laser cementation of woodworking tools, which allows to increase the operational stability no less than twice. The tool wear resistance is increased due to carbon saturation of the surface to 1.8-2.0% and the formation of martensite and residual austenite on the surface of the structural composition. The tests results of wear resistance and determination of the period of resistance of the treated tool are given. The modes of laser cementation for the studied grades of tool steels are offered.

    关键词: wear resistance,woodworking tools,laser cementation,hardening,tool steel

    更新于2025-09-19 17:13:59

  • Effect of Laser Quenching on the Microstructure and the Abrasive Wear Resistance of 30KhGSA Steel

    摘要: The results of microstructural studies, the microhardness distribution, and the estimation of abrasive wear resistance of structural 30KhGSA steel samples hardened during continuous irradiation with a multichannel (48 beams) CO2 laser are presented. Fine martensite forms in the hardened zone and the steel has a high hardness and abrasion resistance.

    关键词: abrasive wear resistance,multichannel CO2 laser,laser quenching,structural steel

    更新于2025-09-19 17:13:59

  • Influence of Powder Condition on Surface Properties of Cold-Resistant High-Strength Steel Produced by Direct Laser Deposition Method

    摘要: Direct laser deposition (DLD) allows creating parts of complex shapes and configurations in a single process step without using of additional equipment. Such technologies are required in the shipbuilding industry, aircrafts, gas turbines, mechanical engineering etc., where it is necessary to manufacture large-sized and complex products that have a long technological cycle for production using classical technologies. DLD makes it possible to produce parts of various alloys with mechanical characteristics at the level of the wrought alloys. The publication is described direct laser deposition of high-strength cold-resistant steels results. Besides mechanical properties of material, the exploitation properties of the structure are also significantly important. Results of corrosion, abrasive-corrosion and tribotechnical tests are shown.

    关键词: corrosion resistance,high-strength steel,abrasive-corrosion resistance,Direct laser deposition,cold-resistant steel,initial powder condition,wear resistance

    更新于2025-09-16 10:30:52

  • Influence of Work Media on Surface Property of Compacted Graphite Cast Iron Processed by Laser Local Processing

    摘要: In order to enhance surface property of brake materials, compacted graphite cast iron (CGI) with non-smooth surface was processed by laser local processing. This study focuses on the influence of the work media on wear resistance and thermal fatigue resistance of specimens. The results showed that when the work media were air and water respectively, laser local processing could enhance surface property of CGI. Changing work media could not change phase compositions of the laser processing area, but refined their microstructures, which enhanced their micro-hardness. By this way, the specimens’ wear resistance and resistance to thermal crack initiation were further improved, while their resistance to thermal crack propagation was influenced by cracks on bionic units.

    关键词: Work media,Laser,Compacted graphite cast iron,Wear resistance,Thermal fatigue resistance

    更新于2025-09-16 10:30:52