TEXTURES OF TANTALUM METAL SHEETS BY NEUTRON-DIFFRACTION

The orientation distributions of six tantalum samples, TaPA, TaG1, TaG 2, TaQ2-S1, TaQ2-S2 and TaQ2-S4, were studied by neutron diffraction a nd ODF analysis. The TaPA specimen is a commercial tantalum sheet with an unknown fabrication history. The TaG1 and TaG2 were fabricated fro m a powder metallurgical ingot by uniaxial compression, and the TaQ2 t ype samples were fabricated from commercial stock by similar uniaxial forging. TaQ2-S1 is the section closest to the centre of the forged di sc, S2 is the intermediate section, and S4 is the section adjacent to the periphery. The texture of TaPA consisted of many components, inclu ding {014}[100], {111}[321BAR], {100}[010], and [111]/[100] double-fib re textures with the fibre axes oriented parallel to the normal direct ion. The two TaG-type specimens were dominated by the [111]/[100] doub le-fibre texture, accompanied by a weak {100}[010] cube texture. The t hree sections of TaQ2 had much higher degrees of texture than the TaG- type samples, with an extremely strong (111) peak, which consists of ( 111)[112BAR], (111)[112BAR], and [111] fibre texture. The average pole density of the three equivalent orientations of (111)[112BAR] was the strongest for the S1 with over 150 multiples of random distribution ( mrd), and gradually decreased with increasing radial distance to about 100 mrd for the S4 section. On the other hand, the average intensity of (111)[112BAR] type orientations was increased from about 40 mrd at S1 to about 100 mrd for the S4 section.