超重力熔铸梯度材料制备饲草料收获机械自磨锐切刀  

Study on self-sharpening cutters for forage harvesting machine with functionally gradient material prepared by combustion synthesis melt-casting under ultra-gravity field

作　　者：宋月鹏[1,2] 高雪[1] 李法德[1] 宋占华[1] 高东升[2] 杨增朝[3] 李江涛[3] 

机构地区：[1]山东农业大学机械与电子工程学院,泰安271018 [2]山东农业大学园艺科学与工程学院,泰安271018 [3]中国科学院理化技术研究所,北京100190

出　　处：《中国科学：技术科学》2018年第1期94-100,共7页Scientia Sinica(Technologica)

基　　金：山东省现代农业产业技术体系果品产业创新团队资金(编号:SDAIT-06-12;SDAIT-06-1);国家十三五智能农机装备重点研发计划(编号:2016YFD0701701);山东省农机装备研发创新计划(编号:2017YF003);山东农业大学″双一流″科技创新团队专项(编号:SYL2017XTTD07)资助项目

摘　　要：采用Fe_3O_4/Al铝热体系,在超重力场中熔铸出硬度呈梯度分布的复合材料,而后制备出饲草料收获机械的自磨锐切刀并进行了现场试验.结果表明,Fe_3O_4/Al铝热剂体系的绝热温度为3148.2 K(Fe的沸点温度),约2 mol%的产物Fe以气相存在.体系内添加约15 mass%的高硬铁基合金颗粒(钒铁、铬铁、锰铁、钼铁等)稀释剂,可使Fe产物全部以高温(3148 K)低黏度液相存在,这对于超重力场中梯度材料成型十分有利.梯度材料的基体是具有择优取向的柱状晶组织,高硬铁基合金颗粒沿超重力方向呈线性排列且与基体冶金结合,由于密度及熔点不同,不同颗粒在复合材料内的分布状况有较大差异,这是材料硬度呈梯度变化的主要原因.新材料制备的饲草料收获机械切刀刃面硬度呈梯度分布,工作过程中会均匀磨损而形成自磨刃,始终保持锋利的切割性能.现场试验结果表明,该自磨锐切刀具有良好的使用效果.Functionally hardness gradient material（FGM） was fabricated by combustion synthesis melt-casting under ultra-gravity feild with Fe3O4/Al thermit. With the original FGM, the self-sharpening cutters for forage harvesting machine were prepared for field experiment. The results indicated that the adiabatic temperature of Fe3O4/Al thermit is 3148.2 K（boiling point of iron） with about 2 mol% Fe production in gas phase. By adding high-hard ferrous alloy particles（about 15 mass%） like ferrovanadium,ferrochromium, ferromanganese, ferromolybdenum as diluent in thermit, the Fe production of gas phase will be eliminated, which was beneficial to the FGM formation process in ultra-gravity field. The FGM microstructure was columnar eutectic matrix of iron/iron carbides with ferrous alloy particles distributed by dispersed and inearly sequenced. The most of discrepancies of distribution characteristics for different particles were exhibited because of their difference of density and melting point. The aspect leads to the gradient variation of hardness distribution for the FGM and homogeneous and gradient abrasion in the working process. The selfsharpening cutters for forage harvesting machine were prepared by FGM. Field experiment indicated that the new cutters had excellent cutting performance.

关 键 词：超重力熔铸 饲草料收获机械 梯度材料 自磨锐切刀 绝热温度 

分 类 号：S817.11[农业科学—畜牧学]