Bonding agent shear tests on steel laminations including irradiated test pieces with radiation doses of between 107 and 109 rad

Experiments were carried out to evaluate the shear strength of various bonding agents used to bond steel laminations as an alternative to riveting or welding. Appropriate curing cycles were applied to the various bonding agents. The curing cycle was found to be quite critical to the shear strength of the bond. Additional tests were carried out on irradiated shear test specimens with radiation doses of between 10⁷ and 10⁹ rad for two bonding agents. The shear strength of the test samples started to decrease significantly above 10⁸ rad. Stabolit 70 exhibited the highest shear strength of the resins tested; however, the value attained by Epoxylite 4239 was adequate for magnet construction. As an example, an Epoxylite 4239 impregnated laminated magnet end plate of the 5-tonne dipole magnets installed in the ESRF storage ring in Grenoble is shown