开沟器铲尖表面等离子熔覆Mo_(2)FeB_(2)涂层制备及其磨损性能  

Preparation and wear properties of plasma cladding Mo_(2)FeB_(2)coating on the surface of the furrow opener tip

作　　者：刘敬春 田铁柱 赵建国[1] 王会强[1] 郝建军[1] LIU Jingchun;TIAN Tiezhu;ZHAO Jianguo;WANG Huiqiang;HAO Jianjun(College of Mechanical and Electrical Engineering,Hebei Agricultural University,Baoding 071001,China)

机构地区：[1]河北农业大学机电工程学院,保定071001

出　　处：《农业工程学报》2024年第9期39-48,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：河北农业大学引进人才科研项目(ZD201717);河北农业大学理工基金项目(LG201801);河北省现代农业产业技术体系建设专项(HBCT2024040207)。

摘　　要：为了解决开沟器铲尖耕作过程中耐磨性差、易失效的问题,利用等离子熔覆技术在开沟器铲尖表面制备Mo_(2)FeB_(2)金属陶瓷涂层,并对其微观组织结构、物相组成、显微硬度以及耐磨性能进行研究。通过正交试验得到熔覆层制备的最优工艺参数组合为:熔覆电流80 A,熔覆距离10 mm,熔覆速度20 cm/min,并以此来制备耐磨熔覆层。结果表明,熔覆层与基体呈现良好冶金结合,其组织主要由方形、蝶状、十字镖形、树形以及不规则长条状的硬质相、网状共晶组织和铁基粘结相组成,其主要物相组成为Mo_(2)FeB_(2)、M_(3)B_(2)(M:Mo,Fe,Cr)、(Cr,Fe)7C3、MoB、CrB、Fe2B以及Fe-Cr固溶体。熔覆层的平均显微硬度为9618 MPa,为开沟器铲尖基体的2.79倍。相同工况下的磨损试验表明熔覆层的平均磨损量(19.20 mg)和平均摩擦系数(0.294)与基体相比分别降低了52.9%和42.4%;不同载荷下的磨损试验表明,随着载荷的增加,熔覆层与基体的摩擦系数呈现逐渐减小的趋势,但熔覆层的整体摩擦系数均低于基体,且其磨损形貌较基体轻微。土槽试验结果表明,熔覆层开沟器铲尖的平均磨损量(4.60 g)比常规开沟器铲尖(15.54 g)降低了70.4%;田间试验结果表明,在实际土壤环境中,开沟器铲尖熔覆层的平均磨损量(34.34 g)仅为常规开沟器铲尖(79.06 g)的43.4%,通过对比磨损形貌发现,熔覆层的存在可以有效抵御土壤磨损,使开沟器铲尖在经过长时间的磨损后能最大程度的保持原貌,从而使其表现出优异的耐磨性能。该研究结果可为提高农机触土部件的耐磨性提供理论参考和可行技术方案。Here Mo_(2)FeB_(2)cermet coating was prepared on the surface of the furrow opener tip using plasma cladding.The microstructure,phase composition,microhardness and wear resistance of the coating were investigated to improve the wear resistance and to address the susceptibility to failure in the tillage process.Firstly,cladding current,cladding speed,powder delivery rate and cladding distance were set as the experimental parameters.The optimal combination of process parameters was obtained using orthogonal test:cladding current 80 A,cladding distance 10 mm and cladding speed 20 cm/min.Subsequently,the wear-resistant cladding coatings was prepared under the optimal conditions.The microstructure and phase composition of the cladding coatings were characterized by scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and X-ray diffractometer(XRD).The results revealed that excellent metallurgical bonding was achieved between the cladding coatings and the substrate.The microstructure consisted of square,butterfly,cross darts,dendritic structures as well as irregular long strips of hard phase along with network eutectic microstructure and iron-based bonding phase.The phase composition included Mo_(2)FeB_(2),M_(3)B_(2)(M:Mo,Fe,Cr),(Cr,Fe)7C3,MoB,CrB,Fe2B and Fe-Cr solid solutions.The hardness and wear resistance of cladding coatings were characterized using microhardness tester and the reciprocating friction and wear tester.An outstanding decreasing trend in microhardness from the surface to the substrate was observed for the cladding coatings,indicating a smooth transition in stress between cladding coatings and the substrate.The average microhardness of the cladding coating reached 9618 MPa,which was 2.79 times higher than that of the furrow opener tip.The wear test showed that the average wear amount(19.20 mg)and the average friction coefficient(0.294)of the cladding coating were reduced by 52.9%and 42.4%,respectively,compared with the substrate.Wear tests under various loads revealed that the friction c

关 键 词：农业机械 显微结构 硬度 开沟器铲尖 等离子熔覆 Mo2FeB2 磨损 

分 类 号：S222[农业科学—农业机械化工程]