陈翔,张德强,李金华,郭海华,姚芳萍,朴若华.热流密度对高速钢刀具多道熔覆WC/Co陶瓷层组织与性能的影响[J].表面技术,2024,53(13):207-219.
CHEN Xiang,ZHANG Deqiang,LI Jinhua,GUO Haihua,YAO Fangping,PU Ruohua.Effect of Heat Flux on Microstructure and Properties of High-speed Steel Cutter WC/Co Ceramic Layer by Laser Multiple-channel Cladding[J].Surface Technology,2024,53(13):207-219 |
| 热流密度对高速钢刀具多道熔覆WC/Co陶瓷层组织与性能的影响 |
| Effect of Heat Flux on Microstructure and Properties of High-speed Steel Cutter WC/Co Ceramic Layer by Laser Multiple-channel Cladding |
| 投稿时间：2023-04-22 修订日期：2023-10-09 |
| DOI：10.16490/j.cnki.issn.1001-3660.2024.13.020 |
| 中文关键词: 激光熔覆 热流密度 WC/Co陶瓷熔覆层 显微组织 高速钢刀具 多道熔覆 |
| 英文关键词:laser cladding heat flux WC/Co ceramic cladding microstructure high-speed steel cutter multi-channel cladding |
| 基金项目:辽宁省教育厅高等学校基本科研项目(LJKMZ20220967) |
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| Author | Institution |
| CHEN Xiang | Engineering Training Center,Liaoning Jinzhou 121001, China |
| ZHANG Deqiang | School of Mechanical Engineering and Automation, Liaoning University of Technology, Liaoning Jinzhou 121001, China |
| LI Jinhua | School of Mechanical Engineering and Automation, Liaoning University of Technology, Liaoning Jinzhou 121001, China |
| GUO Haihua | School of Mechanical Engineering and Automation, Liaoning University of Technology, Liaoning Jinzhou 121001, China |
| YAO Fangping | School of Mechanical Engineering and Automation, Liaoning University of Technology, Liaoning Jinzhou 121001, China |
| PU Ruohua | Training Center, Dalian Economic and Trade School, Liaoning Dalian 116000, China |
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| 中文摘要: |
| 目的 研究高速钢刀具表面激光多道熔覆WC/Co陶瓷层时，热流密度对熔覆层道次间的影响规律，以及多道熔覆层制备时的参数选择。方法 建立多道单层激光熔覆理论模型，并利用模拟仿真和实验的方法，以热流密度作为评价指标，对激光热源的不同参数和熔覆层组织与性能进行耦合分析。结果 当热流密度小于24.06×106 W/m2时，熔覆层内形成细长的枝状晶。当热流密度在36.09×106~39.82×106 W/m2变化时，熔覆层内形成以胞状、枝状为主要强化相的多晶体混合组织。当热流密度大于44.11×106 W/m2时，熔覆层组织形成稳态的块状结构。不同热流密度下，熔覆层的物相组织均由Fe3W3C、Co3W3C、Mo3Co3C、W2C、WC、Cr3Mo、(Cr,Fe)7C3和多种间隙化合物组成。结论 当第n道熔覆层制备完成后，受到后续第n+1道熔覆层制备时热流密度的影响较大，而此后道次的影响较小。熔覆层内部组织形态随着热流密度的增加从细长的枝状晶向胞状晶转变，再逐渐形成稳态块状晶。熔覆层内各位置的显微硬度值随着热流密度的增加而先增大，随后逐渐减小。较大的热流密度会导致基材参与熔覆的质量增加，但降低了基材的抗弯曲强度，加大了熔覆层及基材断裂的可能性。当热流密度为36.09×106 W/m2时，是一组较为理想的工艺参数选择。 |
| 英文摘要: |
| It is an advanced technology of surface modification, repair and remanufacturing by laser cladding, which has an incomparable advantage over traditional cutter repair methods in surface modification and damage remanufacturing of cutting tools. Cermet powder can effectively increase the hardness of cladding layer, so that it can meet the basic hardness requirements of cutter. WC/Co cermet powder is one of the ideal materials for cutter repair. The work aims to study the effect mechanism of the heat flux on the multi-channel cladding layer and the selection of parameters in the preparation of multi-channel cladding layer by laser on multi-channel WC/Co ceramic cladding layer on the surface of high-speed steel cutter. By establishing the theoretical model, the COMSOL Multiphysics was used to conduct simulation analysis on the multi-channel laser cladding process and the temperature field of the multichannel model, and the YLR-3000 fiber laser processing system was adopted to prepare WC/Co single-layer multi-channel ceramic cladding layer on 45 mm×30 mm×10 mm high-speed steel cutter surface by coaxial powder feeding process. The samples were cut by wire cutting and the microstructure of cladding section was observed and analyzed by Axio Vert.A1 inverted metallographic microscope. The microstructure of cladding layer was analyzed by S-3000N scanning electron microscope (SEM) and NORAN-QUEST Ⅱ energy dispersive spectrometer (EDS). The hardness of cladding layer was measured by HVS-1000 microhardness tester. The phase characterization was analyzed by D/MAX-2500 X-ray diffractometer. The multi-factor laser process parameters were coupled and the morphology, structure and properties of cladding layer were analyzed by the heat flux (qn). The correctness of the theoretical model was verified by simulation analysis, and the effect law of heat flux between adjacent channels of single-layer and multi-channel cladding layer was obtained. By the simplified experiment, the effect law of heat flux was found that when the nth cladding layer was prepared, the heat flux of the subsequent n+1 cladding layer was greatly affected, while after that, the effect was less. When the qn was less than 24.06×106 W/m2, the cladding layer usually exhibited pores but few cracks, and the microstructure of the cladding layer was mainly slender dendritic structure. When the qn ranged from 36.09×106 to 39.82×106 W/m2, the cladding layer usually exhibited few pores, and the microstructure was uniform without cracks, forming the polycrystal mixed structure with cellular WC and dendritic W2C as the main strengthening phases. When the qn reached more than 44.11×106 W/m2, the cladding layer usually exhibited more pores and vertical and longitudinal penetrating cracks, and the microstructure was the stable massive WC structure. In the lap zone of cladding layer, the polycrystal mixed structure mainly consisted of cellular and dendritic crystals. In the non-lap zone, the structure mainly consisted of dispersed dendritic crystals. The phase structure of multi-channel ceramic cladding layer was mainly composed of Fe3W3C, Co3W3C, Mo3Co3C, W2C, WC, Cr3Mo, (Cr,Fe)7C3 and a variety of interstitial compounds. The main phases of multi-channel cladding layers with different heat flux are almost the same, but the internal microstructure is closely related to the heat flux in the laser cladding process. With the increase of the heat flux, the microstructure of cladding layer changes from dendritic crystals to cellular crystals, and then gradually forms stable massive crystals. The microhardness values of each position in the cladding layer increase firstly and then decrease gradually with the increase of the heat flux. When the heat flux reaches 36.09×106W/m2, the hardness values of each position in the cladding layer are higher than those at other heat flux, which is an ideal choice of process parameters. Higher heat flux increases the mass of substrate participating in cladding, but reduces the bending strength of substrate and increases the possibility of fracture of cladding layer and substrate. The microstructure between the lap zone and the non-lap zone has a slight difference. The microhardness of the whole cladding layer fluctuates, but the fluctuation has a certain regularity. |
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