Achievements of sustainable manufacturing by machining

Purpose: Manufacturing industry is under increasing pressure of global competition, stricter environmental legislation and supply-chain demand for improved sustainability performance. The latter can be achieved through changes in products, processes and systems which are related to the sustainability issues. Sustainability in manufacturing is an appropriate approach; however it is still unified to a higher production rate and benefit. To encounter this problem academic, scientific, cultural and human organizations have to find the way, on a highest level of decision; maybe to rise the sustainability over production growth. This paper also presents some results from modelling and optimization of sustainable machining of Inconel 718. High temperature alloys, such as Nickel and Titanium alloys, pose significant difficulty in machining, due to their unique thermo-mechanical properties. Design/methodology/approach: In the paper are presented and evaluated two sustainable machining alternatives: cryogenic machining and high pressure assisted machining in comparison to conventional machining. The sustainability performance measures refer to environmental impact, energy consumption, safety, personal health, waste management and costs. The sustainability evaluation is supported with machining experiments on hightemperature Ni-alloy (Inconel 718). It is shown that tooling costs are presenting the major contribution to the overall production costs, when hard-to-machine materials are machined, what is contradictory with previous analysis. Findings: As a result, it is shown that sustainable machining alternatives offer economic, environmental and social performance improvement in comparison to conventional machining. The results of the experimental part show that appropriate cooling/lubrication application can provide improved overall machining performance while satisfying sustainable issues in terms of enhanced machined surface quality, tool-life, chip breakability, power consumption and increasing productivity. Research limitations/implications: The Faculty of Mechanical Engineering in Ljubljana, Slovenia is implementing two new cutting strategies for the machining of a special material – Inconel. The first one is cryogenic machining and the second is material cutting by assistance of high pressure jet cooling lubrication. Both machining strategy are in rang of sustainable manufacturing. The implications of processes like those are not only nature friendly, but also modern spirit for producers and users of products. Originality/value: Paper present the technical description of two modern machining processes, the comparison of them and benefit, advantages and disantvantages. Really new is the strategy and opinion of spirit, which can be included in product over sustainable manufacturing processes.