**6. References**

Aizawa, T., Itoh, K., Iwamura, E. (2010). Nano-laminated DLC Coating for Micro-Stamping, *Proceedings of the International Conference on Metal Forming, Steel Research International*, vol.81-9, (2010), pp.1169-1172, Toyohashi, Japan, September 19-22, 2010

Bhushan, B. (2002). Introduction to Tribology, Wiley, New York

132 Metal Forming – Process, Tools, Design

theory of tribology.

**Author details** 

**Acknowledgement** 

valuable advice and support.

**6. References** 

initial surface geometry of the work material.

Tetsuhide Shimizu, Ming Yang and Ken-ichi Manabe

*Tokyo Metropolitan University, Japan* 

fabrication of tiny micro cups with minimum 0.5 mm in diameter. By providing the different microtools with different surface properties, the high sensitivity of the forming force to the different surface conditions of micro tools has been clearly recognized. Especially, the ironing force and its deviation have the large differences. The surface observation of the drawn cup demonstrates the importance of the tool surface roughness and the material compatibility between the tool and material, in view of the occurrence of adhesion and abrasive wear. In the additional investigation of the influence of material surface roughness, the higher friction force for the bright smooth surface is indicated. This appears to be attributed to the real area of contact during the process, which is strongly dependent on the

Furthermore, the FE model with surface asperities has been proposed and the availability and the validation of this model are demonstrated. The calculation results of this surface roughness model under the different combination conditions of surface asperities are well corresponded to the experimental results. The general tendency of the interaction of the surface asperities between the tools and the workpieces is explainable in terms of the classic

Since the sensitivity to the surface properties for the global forming behaviour becomes higher with decreasing the scale dimensions, the proper design of the tool and the material are required more precisely in microforming. In other words, the microscopic geometry of the surface of tools and materials would become a significant parameter of controlling global deformation behaviour in microforming. The tribological optimisation by the surface

The authors gratefully acknowledge the support from JSPS (Japan Society for the Promotion of Science) under a JSPS Research Fellowships for Young Scientists. In the whole experimental work of micro-deep drawing, the authors also particularly indebted to Mr. Kuniyoshi Ito at Micro Fabrication Laboratory (formerly at Seki Corporation) for his

Aizawa, T., Itoh, K., Iwamura, E. (2010). Nano-laminated DLC Coating for Micro-Stamping, *Proceedings of the International Conference on Metal Forming, Steel Research International*,

vol.81-9, (2010), pp.1169-1172, Toyohashi, Japan, September 19-22, 2010

texturing technology for micro-tooling and materials would be the future tasks.

Engel, U. (2006). Tribology in Microforming, *Wear,* Vol.260, (2006), pp. 265-273


Yang, M. & Osako, A.(2008). Application of Ion Irradiation for Surface Finish of Microforming Die, *Journal of Materials Processing Technology*, vol. 201, (2008), pp.315-318

**Chapter 6** 

© 2012 Oliveira, licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use,

distribution, and reproduction in any medium, provided the original work is properly cited.

© 2012 Oliveira, licensee InTech. This is a paper distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**Towards Benign Metal-Forming:** 

Additional information is available at the end of the chapter

manufacturing processes-related);

Marta Oliveira

**1. Introduction** 

http://dx.doi.org/10.5772/50359

**The Assessment of the Environmental** 

**Performance of Metal-Sheet Forming Processes** 

In the last decade, significant attention has been devoted to the assessment of the environmental impact of manufacturing processes and machine-tools, defining the most important factors to be covered and proposing methodologies to support the analysis of their individual contributions. The work published has established that the environmental impact of a manufacturing process is mainly affected by the consumption of 3 types of resources, namely:

1. The full set of resources used to obtain the machine-tool, accounted as input-output substances associated to the components production and their assembly (materials- and

2. The electricity required during operation, accounted as the specific process energy

3. Other process- or operation-related resources, apart from electricity, accounted as input-output substances associated to the use of the machine-tool (consumed directly in the process, by auxiliary systems during operation or in maintenance operations).

Most of the studies dealing with this triangular perspective focus the analysis of chipping processes (Dietmair & Verl, 2010; EBM, 2010; Gutowski et al., 2006; Kuhrke et al., 2010; Pusavec et al., 2010a,b; Rajemi et al., 2010). Other pure metal forming processes, such as chipless-shaping processes, typically involve no significant material waste or consumables usage, and the savings on the electrical consumption of the machine-tool become the dominant factor to analyse during the use-stage (Santos et al, 2011). As advanced by Gutowski (Gutowski et al., 2006), the total energy required for operation of a machine-tool is not constant, as many life-cycle assessment (LCA) tools assume, and instead the system total electricity consumption, *Pactive,System*, should be

(SPE) related to the main functionality of the machine-tool;

decomposed in a fixed and a variable parts, according to Eq. (1):
