Simulation of neutron damage by means of light ions produced by a charged particle accelerator requires the use of specimens having a relatively small irradiated area in order to obtain a high displacement damage rate. The irradiated zone must also be thin (∼ 20 to 200 µm typically) to ensure homogeneity of the damage and to avoid excessive specimen heating due to absorption of beam energy.

To gauge the effect of very thin specimens on the mechanical behavior of Type 316 stainless steel, three series of comparative tests have been performed: tension tests on miniature specimens of 2 mm width, thermal creep tests using this same type of specimen, and fatigue crack growth measurements in 8-mm-wide notched specimens. Experimental results for thin, reduced-size specimens have been compared both with those for rather thicker specimens of the same design and with published data for specimens of standard dimensions.

Tension tests on the miniaturized specimens in the temperature range of 297 to 1123 K indicated little dependence of the yield stress and the ultimate tensile stress on thickness, while elongation to fracture tended to decrease with decreasing thickness. A negligible influence of thickness on thermal creep behavior was observed for tests carried out in vacuo. Fatigue crack growth rate and number of cycles to crack initiation were found to be similar in both thin and thick specimens.