Characteristic studies of brass particulates fabricated by modulation assisted machining

Abstract

Aim of the current study is to produce particulates of different size and shape using modulation assisted machining (MAM). In MAM, controlled vibration of high amplitude and low frequency given to the tool helps in breaking the chip–tool contact during machining. Controlled breakage of chip–tool contact produces the chips as particulate at a rate of frequency of modulation. Size and shape of the particles produced by MAM can be controlled by varying modulation and machining conditions. In the current investigation, particulates of different shapes and size ranging from 100 μm to 5 mm and aspect ratio of ∼10 were produced using MAM. Morphology of the particulates produced at different conditions was investigated using scanning electron microscopy and tool maker’s microscope. Vickers’s microhardness testing was done to study and understand the variation of hardness in bulk brass and chip particulates produced using MAM. Nearly a 52 % increase in microhardness was observed in 100-μmsized chip particulates as compared to bulk material. To confirm this observation, microstructure analysis of bulk brass and chip particulate was done. Refined grain structure of chip particulate might have contributed to the increased hardness of the particulate as compared to bulk. Effect of modulation and machining parameters on deformation level of the chips particulates produced during MAM was also investigated using X-ray diffraction. It has been observed that with decrease in particulate size, internal strain increases and crystallite size decreases.