目的 加工-强化一体化技术可有效避免加工表面形态损伤,正逐步取代传统激光强化技术,成为Ti6Al4V表面高效性能-精度协同制造的重要手段之一。为实现Ti6Al4V表面强在海洋工程领域耐腐蚀性、高强度需求。方法 本研究将加工-强化一体化技术拓展至不同含量的石墨-B4C复合涂层,提出激光合金化磨削工艺实现Ti6Al4V表面的硼碳强化。通过对比实验研究了B4C含量对涂层导热性、熔池均匀性、合金化表面微相组成、形貌精度及力学性能的影响。结果 含25%B4C的复合涂层具有优异的导热性。激光合金化磨削表面粗糙度Sa约为3.3 μm,其微相组成均匀。颗粒状与针状析出物使合金化表面高达900HV,显著改善其耐磨性。硼元素的引入弥补了石墨渗碳涂层Ti6Al4V表面耐腐蚀性弱的不足,但当涂层中B4C含量过高时,表层材料的微观相成分和宏观形态都会变得不均匀,使加工表面的硬度、耐磨性和耐腐蚀性能下降。结论 激光合金化磨削实现了硼碳强化Ti6Al4V表面的性能-精度协同制造,推动了加工-强化一体化技术的工业化实践,对钛合金抗疲劳制造具有重要的工程价值。
Abstract
Ti6Al4V titanium alloy is widely recognized as a metallic material with outstanding comprehensive performance, encompassing high specific strength, superior corrosion resistance, and excellent biocompatibility. Owing to these synergistic advantages, it demonstrates irreplaceable significance across a broad spectrum of high-demand fields, ranging from aerospace (e.g., aircraft structural components and engine parts) and military engineering (e.g., precision weaponry and armor systems) to marine engineering (e.g., offshore platform components and deep-sea exploration equipment) and biomedicine (e.g., orthopedic implants and dental prostheses). While, in practical applications, Ti6Al4V components often encounter challenges such as complex stress environments, friction and wear, and corrosion. Their surface properties largely determine the overall service performance and service life of the components. Traditional machining methods, such as grinding, milling, turning, are often utilized to realize the surface finishing. However, the mechanical properties of the machined surfaces can not be guaranteed. So the heat treatment methods including carburization, nitriding quenching, laser quenching, and even shot peening are applied to strengthen the surface. It should be noticed that the extra residual stress, the microstructure content and the surface precision become worse under heat treatment. The integrated machining-strengthening technology avoids damage to the surface morphology and is gradually replacing the traditional laser coating technology to realize efficient performance-precision synergistic manufacturing of Ti6Al4V surfaces. However, the existing methods are only applied to pure graphite coatings, and the comprehensive performance of carburized Ti6Al4V surfaces are resistant to meet the demand. Therefore, this study extends the integrated machining-strengthening method to different content graphite-B4C composite coatings and proposes a laser-alloyed grinding to achieve boron-carbon strengthening of Ti6Al4V surfaces. Comparative experiments are conducted to investigate the effects of B4C content on the thermal conductivity of the coating, homogeneity of the molten pool, and the microphase composition, morphology accuracy and mechanical properties of the alloyed surfaces. The composite coating containing 25% B4C has excellent thermal conductivity. A flat alloyed surface (surface roughness Sa=3.3) with uniform microphase composition is obtained after laser-alloyed grinding. Granular and acicular precipitates give the alloyed surface high hardness (900HV) and wear resistance. Although the carbon element can enhance the surface hardening effect by sacrificing the corrosion resistance property, the boron element can be an extra supplement for a better comprehensive property characteristic. However, when the content of B4C in the coating is excessively high, both the microscopic phase composition and macroscopic morphology of the coating become inhomogeneous, thereby leading to a decrease in hardness, wear resistance, and corrosion resistance of the machined surface. Moreover, the coating's laser energy absorption rate and thermal conductivity decrease, and consequently, the substrate material undergoes uneven heating. With the further increase in B4C content, the surface morphology of the molten groove deteriorates, and the formation of crack and porosity defects occurs within the alloyed molten pool. Laser-alloyed grinding enables performance-accuracy synergistic manufacturing of boron-carbon strengthened Ti6Al4V surfaces and promotes the integrated machining-strengthening method to industrial practice, which is vitally important in the field of anti-fatigue manufacturing of titanium alloy.
关键词
Ti6Al4V /
激光合金化磨削 /
石墨-B4C复合涂层 /
性能-精度协同制造
Key words
Ti6Al4V /
laser-alloyed grinding /
graphite-B4C composite coating /
performance-accuracy synergistic manufacturing
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参考文献
[1] LI Z, ZHAO W, ZHANG H, et al.Microstructure and Corrosion Resistance of Fusion Zone in Ti-6Al-4V Alloy Welded Using Pulsed- and Continuous-Wave Lasers[J]. Corrosion Science, 2023, 220: 111269.
[2] RIBEIRO-CARVALHO S, PEREIRA R, HOROVISTIZ A, et al.Intelligent Machining Methods for Ti6Al4V: A Review[J]. Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering, 2021, 235(4): 1188-1210.
[3] ZHONG C L, LIU J N, ZHAO T, et al.Laser Metal Deposition of Ti6Al4V—A Brief Review[J]. Applied Sciences, 2020, 10(3): 764.
[4] LIU S Y, SHIN Y C.Additive Manufacturing of Ti6Al4V Alloy: A Review[J]. Materials & Design, 2019, 164: 107552.
[5] HONG Y, SUN C, XIU S C, et al.Strengthening Surface Generation Mechanism of Carburizing-Assisted Grinding[J]. Tribology International, 2023, 180: 108300.
[6] PRANDO D, BRENNA A, BOLZONI F M, et al.Electrochemical Anodizing Treatment to Enhance Localized Corrosion Resistance of Pure Titanium[J]. Journal of Applied Biomaterials & Functional Materials, 2017, 15(1): 19-24.
[7] LIU C X, WANG Q C, ZHAO B, et al.A Novel Biofunctional TaCu Coating on Ti6Al4V by CVD Method[J]. Materials Letters, 2024, 366: 136586.
[8] SHU L S, WU H, HENG Z, et al.Optimization, Microstructure, and Properties of Ti-6Al-4V Coatings Fabricated by Laser Cladding[J]. Journal of Materials Engineering and Performance, 2023, 32(17): 7946-7959.
[9] PAYDAS H, MERTENS A, CARRUS R, et al.Laser Cladding as Repair Technology for Ti-6Al-4V Alloy: Influence of Building Strategy on Microstructure and Hardness[J]. Materials & Design, 2015, 85: 497-510.
[10] JIANG X J, WANG S Z, FU H, et al.A Novel High-Entropy Alloy Coating on Ti-6Al-4V Substrate by Laser Cladding[J]. Materials Letters, 2022, 308: 131131.
[11] LI Y X, ZHANG P F, BAI P K, et al.TiBCN-Ceramic-Reinforced Ti-Based Coating by Laser Cladding: Analysis of Processing Conditions and Coating Properties[J]. Coatings, 2019, 9(6): 407.
[12] MANSOURA A, DEHGHAN S, BARKA N, et al.Investigation into the Effect of Process Parameters on Density, Surface Roughness, and Mechanical Properties of 316L Stainless Steel Fabricated by Selective Laser Melting[J]. The International Journal of Advanced Manufacturing Technology, 2024, 130(5): 2547-2562.
[13] POPOOLA A P I, PHUME L, PITYANA S, et al. In-Situ Formation of Laser Ti6Al4V-TiB Composite Coatings on Ti6Al4V Alloy for Biomedical Application[J]. Surface and Coatings Technology, 2016, 285: 161-170.
[14] LIU D, HE D Y, LI H L, et al.Multi-Ceramic Phases Synergistically Reinforced Titanium Matrix Composite Coating Deposited by Laser Cladding: Effect of B4C Content on the Microstructure and Wear Properties[J]. Surface and Coatings Technology, 2025, 496: 131648.
[15] HONG Y, LIANG C J, SUN C, et al.20CrMnTi Surface Strengthening Based on Laser-Assisted Carburizing Grinding[J]. Materials Characterization, 2024, 208: 113631.
[16] SUN C, HONG Y, XIU S C, et al.Surface Strengthening Mechanism of the Active Grinding Carburization[J]. Tribology International, 2023, 185: 108569.
[17] HONG Y, SUN C, MA L, et al.Properties-Accuracy Synergistic Manufacturing of Ti6Al4V Surface Based on Laser Carburizing Grinding[J]. Tribology International, 2024, 192: 109329.
[18] HONG Y, SUN C, GUO Q, et al.High-Performance Ti6Al4V Surface Manufacture by Laser Carburising-Assisted Grinding[J]. Tribology International, 2024, 198: 109912.
[19] SEO D M, HWANG T W, MOON Y H.Carbonitriding of Ti-6Al-4V Alloy via Laser Irradiation of Pure Graphite Powder in Nitrogen Environment[J]. Surface and Coatings Technology, 2019, 363: 244-254.
[20] ROY S, SUWAS S, TAMIRISAKANDALA S, et al.Development of Solidification Microstructure in Boron- Modified Alloy Ti-6Al-4V-0.1B[J]. Acta Materialia, 2011, 59(14): 5494-5510.
[21] ACAR M T, ÇOMAKLı O, YAZıCı M, et al. The Effect of Doping Different Amounts of Boron on the Corrosion Resistance and Biocompatibility of TiO2 Nanotubes Synthesized on SLM Ti6Al4V Samples[J]. Surfaces and Interfaces, 2024, 50: 104472.
[22] ZHENG B W, DONG F Y, YUAN X G, et al.Microstructure and Tribological Behavior of in Situ Synthesized (TiB+TiC)/Ti6Al4V (TiB/TiC=1/1) Composites[J]. Tribology International, 2020, 145: 106177.
[23] BERMINGHAM M J, MCDONALD S D, NOGITA K, et al.Effects of Boron on Microstructure in Cast Titanium Alloys[J]. Scripta Materialia, 2008, 59(5): 538-541.
[24] SINGH G, RAMAMURTY U.Boron Modified Titanium Alloys[J]. Progress in Materials Science, 2020, 111: 100653.
[25] GOLYSHEV A, ORISHICH A.Microstructure and Mechanical Characterization of Ti6Al4V-B4C Metal Ceramic Alloy, Produced by Laser Powder-Bed Fusion Additive Manufacturing[J]. The International Journal of Advanced Manufacturing Technology, 2020, 109(1): 579-588.
[26] BAI L L, LI J, CHEN J L, et al.Effect of the Content of B4C on Microstructural Evolution and Wear Behaviors of the Laser-Clad Coatings Fabricated on Ti6Al4V[J]. Optics & Laser Technology, 2016, 76: 33-45.
[27] KUMAR A, SINGH G.Surface Modification of Ti6Al4V Alloy via Advanced Coatings: Mechanical, Tribological, Corrosion, Wetting, and Biocompatibility Studies[J]. Journal of Alloys and Compounds, 2024, 989: 174418.
基金
衢州市科技计划项目（2024K200）; 衢州学院博士启动基金（BSYJ202216）
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