Adhesive 2-layer lamination joints of 18 mass%Cr-8 mass%Ni austenite stainless steel and carbon fiber reinforced polymer (18-8/CFRP joint) were prepared using a new adhesion method consisting of applying low dose of 0.13 MGy of homogeneous low energy electron beam irradiation (HLEBI) to connecting surfaces of the 18-8 and CFRP prior to lamination assembly and hot-pressing in vacuum below 1 Pa for 2 h at 401 « 0.5 K. Although untreated 18-8/CFRP joint exhibited decent adhesion by hot-pressing, application of 0.13 MGy HLEBI dose apparently improved the tensile shear strength,¸B of the 18-8/CFRP joint 58% at median accumulative probability (P B = 0.50) from 4.0 to 6.3 MPa. In addition, applying HLEBI from 0.13 and 0.30 MGy was found to enhance the¸B at all P B . Based on the 3-parameter Weibull equation, the statistically lowest¸B value at P B = 0 (¸s) was increased from zero to 4.39 MPa by the 0.13 MGy HLEBI. XPS (X-ray photoelectron spectrometry) measurements detected carbon on the shear-fractured 18-8 interface indicating the residual epoxy adhered well to the 18-8 by the HLEBI. This is probably a result of adhesion force of 18-8/CFRP being made stronger than the cohesive force of epoxy polymer in the CFRP itself. Since HLEBI cuts the chemical bonds and generates active terminated atoms with dangling bonds in epoxy polymer and passive film on 18-8, the increased adhesion force in the 18-8/CFRP joint can be explained by the chemical bonding and coulomb attractive forces thus induced at the interface. Since the experimental data shows the optimum HLEBI dose is about 0.13 MGy, above which at 0.30 MGy the¸B begins to drop off, carefulness in optimization is highly recommended when applying in industry to insure safety.

Adhesive 2-layer lamination joints of 18mass%Cr-8mass%Ni austenite stainless steel and carbon ber reinforced polymer (18-8/CFRP) were prepared using a new adhesion method consisting of applying low dose of 0.13 MGy of homogeneous low energy electron beam irradiation (HLEBI) to connecting surfaces of the 18-8 and CFRP prior to assembly and hot-pressing in vacuum under atmospheric pressure of about 1 Pa for 2 h at 401 ± 0.5 K. Although untreated 18-8/CFRP joint exhibited decent adhesion by hot-pressing, application of 0.13 MGy HLEBI dose apparently improved the adhesive force of peeling resistance ( o F p ) of the 18-8/CFRP joint 145% at median accumulative peeling probability (P p = 0.50) from 18.9 to 27.4 Nm −1. In addition, the statistically lowest o F p for safety design (F s at P p = 0) iterated by the 3-parameter Weibull equation was raised from zero for the untreated to 5.2 Nm −1 for the 0.13 MGy samples indicating increased reliability by the HLEBI. The higher adhesive strength induced by HLEBI was explained by results of XPS (X-Ray Photoelectron Spectroscopy) observations of the peeled surface of 18-8 side of lamination with and without 0.13 MGy-HLEBI. 0.13 MGy-HLEBI slightly increased the number of C=C bonds instead of slightly decreasing the numbers of C-C, C-H and O=C-O bonds near 18-8/CFRP interface. In addition, both increasing oxygen atoms and decreasing hydrogen atoms strongly attributed to bonding force at interface of epoxy of 18-8/CFRP. Since the experimental data showed the optimum HLEBI dose was about 0.13 MGy, above which at 0.13 MGy the o F p began to drop, carefulness in optimization was highly recommended when applying in industry to insure safety.

Adhesion induced by homogeneous low voltage EB-irradiation (HLEBI) under O2 partial pressure from 0.02 mol% to 20 mol% in N2 gas atmosphere of CFRP/Al lamination has been successfully developed. Its adhesive tensile shear strength of CFRP/Al with 0.30 MGy-HLEBI under optimal O2 partial pressure in N2 atmosphere of 0.2 mol% is 8.2 MPa, which is about 1.4 times higher than that (5.9 MPa) of CFRP/Al untreated.

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