【摘要】 针对农业机械耕作部件既要提高耐磨性又要保证强度的问题,提出了一种通过构建仿生表面结构和控制工艺来设计结构/材料二元耦合仿生表面结构的方法。采用球墨铸铁制备具有仿生表面结构的耕作部件使仿生表面由高硬度白口铁构成,从而兼顾部件的耐磨性和机械性能。试验结果表明,在铸造过程中,单纯通过仿生表面结构或局部设置小型冷铁的方法,部件仿生表面结构局部均未能形成白口铁组织,而上述两种方法的结合运用,可实现仿生表面结构的白口化。分析表明,仿生表面结构可限制熔体流动,设置冷铁可提高局部过冷度,两者结合可实现耦合仿生设计。显微硬度和划痕试验表明,耦合仿生表面结构具有较高的局部硬度,相比于芯部基体,其显微硬度值平均提高了35.71%,而形成相同宽度的划痕时,其所需载荷是芯部基体的1.16倍。水润湿性试验表明,耦合仿生表面结构与芯部基体水润湿性也存在一定的差异,相比于芯部基体,其接触角增大了14.91%。此方法适用于生成具有耐磨性能且高强度的耕作部件,在保证部件机械性能的同时,可提高耐磨性和降低土壤粘附。更多还原

【Abstract】 Tillage component wear is a serious concern in agricultural regions. There is a contradiction between the improved hardness of tillage component and weakened mechanical strength. In order to solve this problem,the paper introduced a structure and material coupling bionics surface texture that was acquired by structuring the bionics surface texture and controlling the processing of the cast. The test results showed that the single bionics surface texture or setting small chill did not produce the white iron structure,and via combining the two methods,the white iron structure was appeared. The analysis results indicated that bionics surface texture can limit the melting flow and setting small chill can enhance the part undercooling degree,realizing the design method of the coupling bionics surface texture. The micro hardness test results showed that coupling bionics surface texture has higher micro hardness and the average value was improved by 35. 71% compared with the core matrix. The scratch test results showed that when forming the same width of scratches,it needed 1. 16 times load for the core matrix. The wettability test results showed that the average contact angle of the coupling bionics surface texture was high,and the values were increased by 14. 91% compared with the core matrix. The coupling bionics surface texture can be used to design the tillage component that possesses high wear resistance,high mechanical strength and low soil adhesion.更多还原