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Pure molybdenum sheets were prepared by powder metallurgy and unidirectional rolling process. The microstructure, texture, grain orientation, mechanical properties and fracture mechanism of sintered samples were investigated. The results show that tensile strength and microhardness of 95% rolled sheet are 1028.095 ± 19.32 MPa and 323.2 ± 11.68 HV. The main texture components of (011)〈110〉 is Goss texture with reduction in the range of 70–95%. Two grain orientations of 〈111〉 fiber & 〈100〉 fiber and 〈100〉 fiber & 〈110〉 fiber are formed in the 47% and 95% rolled molybdenum sheets, respectively. Meanwhile, the fiber structure become more refined and oriented in the rolled molybdenum sheets when the rolling reduction is >87%. Brittle characteristics show typical cleavage failure. • Tensile strength and microhardness of 95% rolled sheet are 1028.095±19.32 MPa and 323.2±11.68 HV. • The main texture intensity value of Goss texture is 9.52 in the 95% rolled sheet. • Two grain orientations of <111> fiber & <100> fiber and <100> fiber & <110> fiber are formed in the 47% and 95% rolled molybdenum sheets, respectively. [ABSTRACT FROM AUTHOR]

The 1.0 wt% La - doped molybdenum - 0.6 wt% titanium - 0.11 wt% zirconium (La-TZM) alloy has a maximum tensile strength of 1350 MPa and elongation to failure of 7.5%, at room temperature. In this paper, the fracture behavior of this La-TZM alloy was studied. The La 2 Ti 2 O 7 phase produces micro-cracks during rolling deformation which eventually propagate to full cracks during tensile testing. The reason for the La-TZM fracture is deformation incompatibility and large stress concentrations at the La 2 Ti 2 O 7 particles inducing particle cracking, leading to micro-cracks along the grain boundaries. The La 2 Ti 2 O 7 phase is composed of 69.8 at.% O - 13.3 at.% Ti - 0.6 at.% Zr - 10.4 at.% La and is formed by the La 2 O 3 , TiO 2, and ZrO 2 secondary phases when sintered above 1350 °C. [ABSTRACT FROM AUTHOR]

• A novel of high ductility Mo-2.5 wt% ZrTiO 4 alloy was design. • Ductility reaches the maximum at 2.5 wt% ZrTiO 4 and the room temperature elongation is 25.4% • Mo-ZT alloy strength increases with higher ZrTiO 4 secondary phase content. • The main mechanism of ductility improvement is small-sized sub-crystals are not formed in the molybdenum matrix. Molybdenum materials are widely used in electronics and high-temperature applications because of their high strength and recrystallization temperature, good electrical and thermal conductivity. However, molybdenum brittleness, low ductility, and fracture toughness have been limiting its applications. In this work, a new Mo-ZT (Mo-ZrTiO 4) alloy was designed containing various amounts of the ZrTiO 4 secondary phase, ranging from 0.5 wt% to 3 wt%. The Mo-ZT alloy with 2.5 wt% ZrTiO 4 has the ultimate tensile strength above 1,000 MPa(rolled) and 25% elongation (annealed), which is higher than previously reported molybdenum alloys. Compared with the Mo-1ZT alloy, the elongation is increased by 166% with 2.5 wt% ZrTiO 4 addition. This offers novel insights for improving alloys' ductility. [ABSTRACT FROM AUTHOR]

Previous experimental studies in the Mo-TiC-ZrC-C (TZM) alloy have shown the existence of secondary phases around the composition TiC, ZrC, TiO 2 , ZrO 2 and ZrTiO 4. No research about the interface of secondary phases and Mo matrix was indicated. We characterized the different secondary phases influence on the structure and mechanical properties by the mismatch and electron density. And discovered that ZrTiO 4 has largest lattice misfit and electron density, contributing to better strengthening and toughening of TZM alloy. The ZrTiO 4 interface bonding strength is superior to the other secondary phases. This new understanding opens opportunities for designing high strengthening-toughening Mo alloy. Unlabelled Image • The effect of addition of TiC and ZrC on the strength and elongation of Mo-TiC-ZrC-C is studied • The composition 0.08%TiC-0.11%ZriC-0.06%C showed high strength of tensile strength 1292.65 Mpa and elongation 6.9%. • ZrTiO 4 has largest lattice misfit and electron density, contributing to better strengthening and toughening of TZM alloy. [ABSTRACT FROM AUTHOR]