3. Sustainability assessment for machining of Ti-6Al-4V

Sustainability of a machining process refers to the impact on environment, power consumption and safe for operator, which were satisfied in the experimental works as the cost of tool was reduced in the cryogenic cooling and it also impact on time saving for tool changing and setup time, which result in increasing productivity. An advantage of cutting in cryogenic process is evaporating back of cooling gas (Nitrogen) into air, which ensures the healthy environment for workers.

In experimental work [59], face milling of hardened Ti-6Al-4V at 55 HRC was carried for dry, conventional and cryogenic cooling conditions. Experiment model was designed using software design expert and technique of central composite design (CCD) was selected. Surface finish as response was checked and compared for each scenario of cooling. Resulting values of surface finish were compared based on iso-response technique, and the cutting power, cutting time, material removal rate, machining cost and cutting tool life were calculated as given in following sustainability parameters:

Cutting power: it was found that the cutting power required in cryogenic machining is 61.9% less than cutting power required in dry machining.

Machining cost: it is found that electricity cost is 47.55% less than dry machining and 14.22% less than conventional machining.

Adverse effects of CLF: the adverse effects of conventional coolants are reduced by replacing the coolant with N2 gas. Corresponding cutting power and machining cost are also reduced.

Machining time: machining time for cryogenic machining is 15.12% less and for conventional machining it is 12.51% less than dry machining.

Material removal rate: the material removal rate is 81.12% more for cryogenic than dry machining.

Tool life: cutting tool's life is 5.2 times more for cryogenic cooling which indicates that the waste in the form of damaged tools is reduced.

The coolant used in conventional machining has its adverse effects on worker's health and environment, while the nitrogen gas is harmless. The tool wear rates are also high for dry and conventional. Summarizing all findings, it can be stated that

Industrial Engineering Department, University of Engineering and Technology,

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provided the original work is properly cited.

cryogenic machining supports the sustainable machining.

Sustainable Machining for Titanium Alloy Ti-6Al-4V DOI: http://dx.doi.org/10.5772/intechopen.82344

Author details

Imran Masood

Taxila, Pakistan

117
