Manufacturing Induced Strain and Long-Term Material Performance
MS Helen Smith, Prof. Michael Hill, Prof. Barbara Linke
Funding Body: Electric Power Research Institute
Cold-working, or strain-hardening, is a process where a material is plastically strained at a temperature well below its melting point. Often defined in terms of percent elongation or area reduction, cold work (CW) is more of an overall process than a specific property. Cold-working a part affects many material properties such as hardness and strength, which can have serious impact on its overall performance. For example, negative effects associated with cold-work lead to increased susceptibility to environmentally assisted cracking (stress corrosion cracking) in nuclear plant components. To date, evaluation of cold-work has been mainly qualitative in nature. This research project first aims to identify and evaluate test methods in order to define a quantitative measure for cold work; further work will allow accurate assessment of cold-work levels in components undergoing a multiple process chain.
Figure: Microstructure of stainless steel as-received (left) and after 30% cold working (right). Deformation twins (dark hatching inside grains) and grain elongation are visible.
New Concepts for Bio-inspired Sustainable Grinding
Bio-inspired design is a promising and innovative approach to improve the sustainability of products and processes. This research project aims to explore how nature can inspire improvements in grinding process, and in particular the use of bio-inspired design to find novel process setups for grinding system components. A first report at the NAMRC 2014 conference and journal publication addressed problems such as chip transport and tool cleaning, abrasive wear resistance, self-sharpening, breaking air barriers, cooling, and new process environments. The new bio-inspired concepts and axiomatic design approach will be validated through case studies and experimental tests.
Sustainability Indicators for Finishing Operations
Sustainability of manufacturing processes and abrasive machining is of high importance to production engineers. However, choosing and standardizing the best indicators to evaluate processes sustainability is challenging. There are many sustainability indicators available, but these indicators mostly focus on energy and material efficiency. For finishing operations, these indicators are not suitable as they often relate to the processed material removal volume, which is very small in finishing operation. This research project investigates more appropriate sustainability indicators for finishing operations, which are based on process performance and part quality.
Communicating Corporate, Business and Operational Sustainability Strategies and new decision methodologies
Consumers expect manufacturing companies to act sustainably. Research has shown that companies are starting to develop and communicate their sustainability agenda, but leaving the customer wondering if and how sustainability is really executed down the line. In this project a research methodology was defined to study the sustainability goals and strategies on corporate, business and operational level. The goals and strategies are rated on their conveyance and correlation. These results are visualized in a matrix. A case study with the web-based information of 100 companies revealed that energy, waste, and diversity are the most named sustainability goals. Support for charity programs, smarter programming, reuse of waste heat, efficient lighting systems and childcare/ work time models were the most cited sustainability strategies. Ongoing studies aim to help manufacturing engineers to evaluate the sustainability of discrete manufacturing processes or broader processing strategies. A transparent method to compare and balance the different dimensions of sustainability is a key factor for the successful transfer of academic models into industry.
Life Cycle Analysis of Grinding Tools
To understand sustainability in grinding technology, comprehensive studies on the life cycle of grinding tools are needed. Grinding tools are complex products with a life cycle of their own, including: raw material extraction, tool manufacturing, tool use and end of life. There is a large variety of grit types (spanning from conventional grits such as alumina and silicon carbide to the superabrasives cubic boron nitride and diamond), bond materials (resin, vitrified or metallic bonds), designs (wheels, pins, belts, full-body tools or with tool body, etc.) which result in numerous manufacturing routes. This research project investigates the life stages of grinding tools, while paying close attention to the wear behavior during tool usage. The supply chain of grinding tools can become more transparent to achieve more sustainable grinding tools. Leveraging effects can occur if more sophisticated tools offset their higher economic or environmental impacts through better performance in the grinding process.
Book “Life Cycle and Sustainability of Abrasive Tools” published by Springer: http://www.springer.com/us/book/9783319283456