Machining of aluminium matrix composites such as aluminium silicon carbide are difficult due to the presence of hard and abrasive particles of silicon carbide which causes tool wear, poor surface quality and undesirable chip formation. This work contains the study of the influence of cryogenic assisted turning operation on chip morphology, chip breakability and control on aluminium silicon carbide using uncoated tungsten carbide tool and liquid nitrogen as coolant.

It further made comparison between the results obtained from dry machining with that of cryogenic machining based on these areas of interest. Microstructural analysis of the chips obtained from the dry and cryogenic machining was performed using the light optical microscope and scanning electron microscope. Measurements of the chip thickness, chip width, tool-chip contact length, average chip length and average chip curl diameter was performed to provide insight on the chip breakability process.

Results obtained showed that chip width and thickness varied as the speed varied but did not contribute to the chip breakability. It showed that chip breakability mainly depends on the chip curl diameter and average chip length across the four-cutting condition. Observation of the rake cooling condition gave a lower chip curl diameter, favourable average chip length and short non-helical chips which are more favourable to chip breakability.The influence of the cryogenic on the chip morphology was evident in the sharp difference between the long continuous chip of the dry machining with that of the short continuous chips from the other three cooling condition, the cryogenic cooled operations formed short segmented continuous chip with some presence of micro cracks, fractures towards the chip root and delamination on the outer side of the chips which can be point of crack and stress propagation.

In conclusion, cryogenic cooling influenced the chip morphology and enhanced better chip breakability of aluminium silicon carbide especially when applied from the dual and rake face.