Sustainability Is About Coexistence Between 3ES - Economy, Ecology & Equity

Magazine

Vivek Tomar, Vice President, Ceratizit India Private Limited

Vivek Tomar, Vice President, Ceratizit India Private Limited

Vivek is having experience of more than two decades in metal cutting tool industries & responsible for Project Management, Product Management, Application Engineering & Technical Centre in India for Ceratizit Group

Our lives are connected. Connected at both extrinsic and intrinsic levels with each other, our nature and on a larger scale to this universe. Now to sustain this life, irrespective of variegated needs of individuals, we have been consuming since the dawn of civilization. Alarmingly the growing needs, services, and industrial systems demanded by society has provoked in the last century a great impact on the planet, contributing to the increase in the Metabolic Rift.

The metabolic rift corresponds with the existing distance between the natural capital (provided by the planet) and the social capital; it is also defined by the consumption of energy resources and materials caused by the humans’ economic activities. The mitigation of the metabolic rift is the origin of the current framework that is used to structure and manage Sustainable Manufacturing (SM) from the three dimensions known as: Economic Capital-economy, Environmental capital-ecology and Human capital-equity.

They interact as a whole and in establishing the triple bottom line (TBL or 3E) to achieve three objectives: (1) improve the economic, environmental and human performance, simultaneously; (2) reintegrate the natural ecosystems; and (3) mitigate the metabolic rift leading us to the currently accepted definition of Sustainability: sustainable development is the development that meets the needs of the present, without compromising the ability of future generations, to meet their own needs.

Sustainability Framework In Machining
Sustainability in machining can be assured by reducing energy consumption for machining processes, minimizing waste (less generation of waste and increasing the recycling of waste) and minimizing Carbon footprint of machining processes. The basic framework of Sustainability in machining which consists of the major Strategies which with the help 6 key drivers constructs 3 pillars of Sustainability is well represented in the image.

Process Optimizations
The domain of Process Optimization quite vast as encompasses multiple sub-domains starting from Material selection & drawing study to ultimate delivery of the finished product. This whole work-chain involves CAD, CAM, CAPP, Machine, Cutting tools and so on. Optimization is possible in each domain towards the coveted goal of Sustainability in the following ways.

1. Utilization advanced Thermo-mechanical simulation and Finite Element based process optimizations in terms of Material selection, Coating and designing is contributing significantly in minimizing Energy requirements, environmental hazards & carbon footprints.

2. Advancement of CAD/CAM technologies and integration of CAD/CAPP/CAM at single platform done a remarkable job by simplifying the whole process, reducing Machine uptime and down time.

3. Advanced feature oriented CAM techniques such as Adaptive Roughing ( Profit Milling, Volumill etc) together with Machines with multiple & simultaneous DOF which has reduced machining time and difficulty significantly. As an example switching to Adaptive roughing technologies for machining Ti6Al4V reduces cut time with respect to conventional by 30-40%. Henceforth reducing the machine hour and energy consumption for the same.

Advanced Cutting Tool & Coatings
Sustainable machining is about producing a part by the following concepts:
• Maximize the use of the cutting tool

• Maximize the cycles of regrinding or reworks of the cutting tool
• Minimize CO2 generation during the machining process

In order to minimize CO2 emissions Automotive & Aerospace industry is strongly going towards Materials with higher Strength to Weight ratios; thereby increasing efficiency. But at the same time these materials (Ti6Al4V, Inconel, Nimonic, Stelite etc) are very difficult to machine drawing higher Cutting energy. Hence to reduce the difficulty in machining Cutting material and coating is going continuous and steeper improvements. With CBN, Ceramic (Whisker reinforced & Sialon) and PCD cutting tools we can machine such difficult materials 5 - 10 times faster.

Also advancement in cutting geometry design, sintered 3D Chip Breaker has also reduced specific cutting force requirements and reducing energy demands. Al2O3, AlTiN, TiSiN, AlCr/AlTiN based hard and Heat resistant coatings (both CVD & PVD) has paved the way of increasing tooling life when machining highly abrasive and difficult materials. TiBN and TiB2 based coating has achieved significant life and tribology improvements in machining HRSA and high Si based Al compounds.

Digital Transformation & Industry 4.0
The sky and even beyond is the limit when we talk about adaptation of Industry 4.0 towards sustainability goals. Researchers in manufacturing are currently focusing on the convergence to realize larger benefits of industry 4.0, which is sustainable manufacturing.

Currently, industry experts are utilizing industry 4.0 technologies to address challenges and issues related to TBL of sustainable manufacturing. Transformation of a manufacturing unit into an intelligent factory requires both horizontal and vertical integration (Digital Twin), wherein, all the production areas are integrated. The seamless integration, provided by industry 4.0 technologies and Information & Communication technology platforms, increases the transparency of the production processes and supply chain activities, thus helping optimize all the energy and resources.

Green Lubrication
Cutting fluids are dangerous for health. In a report it is stated that about 80% of the skin diseases are due to the use of cutting fluids. The machinists are facing the problem of skin and respiratory diseases due to metal working fluids. Among the machinist over 1 million workers all over the world are facing toxic effects of cutting fluids, and majority of the cases are related to chest bronchitis.

As per study tooling cost is about 4% of the total machining costs and coolant/lubrication cost is about 15% of total machining cost; therefore huge sustainability gain is possible by avoiding CLF (Conventional Cooling/Lubrication Fluid).

The alternatives are MQL, MQC , Cryogenic Fluid and Dry Cutting. The immediate benefits of these are significant reduction Cutting Power, Machining cost, Machining Time, Tool Life & MRR.

Hybrid Machining Techniques &Additive Manufacturing:
Increasing adaptation of LAM (Laser Assisted Machining) , WJM ( Water Jet Machining) , UVAM( Ultrasonic Vibration Assisted machining ) has shown improved machinability against HRSA materials.

The experimental investigations showed that the ultrasonic vibration–assisted cutting reduced the torque during tapping as compared to the conventional process. They observed a 19.1% reduction in torque, approximately 20.3% reduction in cutting temperature, a superior surface quality, and better machinability. Various possibilities still exist where combinations of different tool materials and coatings along with other sustainable machining strategies, namely, MQL, cryogenic, LAM, and UVAM, may be developed into hybrid processes that could lead to further improvements.

Apart from these, strategies such as the utilization of new and cleaner technologies for manufacturing and the use of 3D printing will also help manufacturers reduce waste generation. Despite the limitations associated with AM, such as material selection and characteristics, low process productivity, geometrical dimension accuracy, surface quality, repeatability and unit cost, five key environmental benefits can be expected from the adoption of AM:
(1) Reduced amount of raw material required in the supply chain;
(2) Reduced need for energy-intensive, wasteful, and polluting manufacturing processes;
(3) More efficient and flexible product design with better functional and operational performance;
(4) Reduced weight of transport-related products and improved carbon footprint.

Conclusion
Sustainability concept revolves around the basic principles of Compassion and Co-Existence between Economy, Ecology & Equity (3E). This is not just a mere concept anymore rather this is ardent need of today and a way to future. EU leaders set 55% target for CO2 emissions cut. EU leaders have agreed on a more ambitious goal for cutting greenhouse gases - reducing them by 55% by 2030, rather than 40%. Likewise all the government bodies are considering sustainability goals across the globe.

To conclude sustainability, as a competitive core idea, should be considered for the optimization of the machining processes, where material efficiency, low energy consumption, and cyclical metabolism can contribute to the mitigation of the metabolic rift and simultaneously to the creation of quality of life.