COFIX project

Development of innovative clamp designs for high-temperature performance

Projet Cofix - MATEX

The aim of this project is to remove one of the key technological barriers to vehicle exhaust systems, and in particular their sealing. It aims to provide a better understanding of the physical and mechanical phenomena involved in clamp assemblies subjected to thermomechanical and vibratory cycling, and in particular the effect of these stresses at high temperatures, with gases in excess of 1000°C.

Clamps to withstand severe stresses

As part of the development of clamps for the latest generation of internal combustion vehicles (exhaust and fluid systems), new clamp concepts are needed that can withstand severe pressure-temperature-vibration stresses. Several avenues of research have been identified to develop clamps that meet all requirements in terms of reliability and performance over time. These include, on the one hand, the development of new material grades, with potential recourse to materials usually used in the aeronautical sector (inconel, titanium), and on the other hand, the design of specific geometric configurations for connections to the new clamp, notably using additive manufacturing approaches.

Anticipating change

The aim of this project is to adapt fastening clamps to new-generation combustion-powered vehicles. The measurement of leakage and stress at high temperature at the joint connection is not currently done by any player in the sector, since leakage is measured globally. The project will also contribute to the development of small, very tightly-tightened clamps to secure the Adblue injector (urea injected into the anti-pollution system), enabling increasingly stringent anti-pollution requirements to be met (Euro 7 standard by 2021 in Europe).

Project partner
Academic laboratories

INSA Centre Val de Loire / Blois Campus

LaMé, CNRS / University of Orléans / University of Tours

Industrial partner

CAILLAU, Romorantin (41)


300,8k€ over 3 years

from regional funds (ARD CVL)


1 post-doctoral fellow

and 3 Master's trainees


Roger Serra