Development of iron-based binder composition for macroheterogeneous composites

Application of composite coatings allows solving the problem of prolongation of service life of quicklyworn equipment parts. The development of iron-based binder composition for composites reinforced with tungsten carbides is imperative to enhance wear resistance of the coatings. Methodology. The macroheterogeneous composites reinforced with tungsten carbides were produced by infiltration at 1453 К during 30 minutes without applying pressure. The Fe?3%C?1,8%B?1%P and Fe?3%C?1,8%B?1%P?0,5%Мо alloys were used as metal binders. The structure of the composites was investigated by metallographic, Xray, and energy dispersive X-ray analyses. To control structural and phase composition of contact interaction zones appearing between the filler and the binder during infiltration an original method of statistical structural analysis was applied. Findings. Alloying the Fe?C?B?P binder with molybdenum is established to allow decreasing the intensity of contact interaction processes between the filler and the molten binder during infiltration. As the result, the undesirable brittle Fe3W3C and austenite phases do not appear in the structure of contact interaction zones. It is shown that the accuracy of quantitative characteristics determination can be essentially improved thanks to application of the suggested statistical analysis of microphotographies. Total entropies of the contact interaction zones phases are calculated using probability density curves showing the hitting of the certain interval by the intensities of the microscope light reflected from the polished section. Originality. The regularities of the structure formation of the contact interaction zones appearing between the W?C filler and the solidified Fe?C?B?P or Fe?C?B?P?Мо binders were investigated. To identify and determine relative phase content the original method of statistical structural analysis was applied. Total entropies of the contact interaction zones phases were calculated which allowed explaining the decrease in dissolution rate of the filler in the molten Fe?C?B?P?Мо binder during infiltration. Practical value. The iron-based binder composition is developed to infiltrate macroheterogeneous composites reinforced with tungsten carbides. The application of the suggested binder allows increasing the wear resistance of the composites due to contact interaction zones being free from the brittle phases. The developed binder can be recommended to obtain composite coatings to protect quickly-worn parts of metallurgical and machine-building equipment working in abrasive and gas-abrasive media.