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.
