**6. Final remarks and future trends**

Tribology, including the study of surface phenomena such as contact, friction, lubrication and wear, plays a fundamental role in metal forming processes, as it directly influences the final quality of the parts produced and the useful life of the tools, which generally have a very high cost. In this sense, the use of mathematical models that represent the adequate friction conditions and the use of computational simulation tools play a fundamental role in reliably predicting the tribological aspects of the forming processes.

Generally, industrial case studies focused on sheet metal forming simulation using finite element methods, includes a constant coulombian friction model and cannot achieve good results when comparing numerical and experimental results, in terms of the prediction of wrinkling as well as ruptures, as presented in this work. However, further improvements are going towards spring back prediction, which includes surface texturing parameters and variable friction approach. All, aiming to a better reliability on tribological modeling of the friction influences for the metal forming process.

The present work shows that there is a growing concern regarding friction phenomena in metal forming. Numerical simulations are already at a very advanced stage in their ability to predict the behavior of the material being manufactured.

## *Tribology of Machine Elements - Fundamentals and Applications*

However, the amount of information that must be collected for the software to be able to simulate with precision is increasing and this will require a greater volume of data associated with the materials of the pieces, tools and metal interfaces. This may seem problematic in terms of costs, however, it must be taken into account that the failure and scrap rates will be practically zeroed, leading to more gains than the efforts to obtain all the necessary properties.
