The longitudinal residual stresses in the friction stir-welded plates of 5A06 aluminium and pure copper were determined using the contour method. The results revealed the presence of high tensile and compressive residual stresses on the aluminium and copper sides, respectively. The residual stresses were detected on the weld zone as well as the thermo-mechanically affected zone (TMAZ) of the aluminium plate. In contrast, the compressive residual stresses in the copper plate had a much narrower width along the weld line. Peak tensile stresses up to 240 MPa were found in the TMAZ of the aluminium plate.

The oxidative coupling of methane over (Bi203)l.x(WO3)x (x=0.2, 0.3, 0.4) oxygen ion conductive oxide catalysts irradiated by microwave has been studied. Compared with a conventional heating mode, the temperature of the catalytic bed is much lower with microwave irradiation and there is a change in selectivity favoring the production of C2 products.

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The spray forming 7055 aluminum alloy is welded by electron beam welding (EBW). After welding, the single solution treatments under different temperatures and then aging treatment (STA) and the stepped solution treatment and then aging treatment (SSTA) are carried out for the welded joints respectively. The effect of different post-weld heat treatment (PWHT) procedures on the microstructure and mechanical properties of welded joints is systematically investigated. Results show that, in as-welded condition, the fusion zone mainly consists of α-Al phase, and there are some precipitated phases such as Mg32(Al,Zn)49, Al7Cu2Fe, Al2CuMg, and a small amount of phase MgZn2 in weld metal. After PWHT, the continuous network structures at grain boundary disappear. There are only a few isolated particle phases at grain boundary, and many ellipsoidal η′ phases and rod-like η phases are precipitated within grains. The mechanical property of welded joint is improved after PWHT. Compared with that of in STA condition, the strengthening effect to welded joint is more obvious after SSTA. In SSTA condition, the hardness of weld zone is close to that of base metal (BM), and the tensile strength of welded joint reaches 486.2 MPa, which is 85.6% of that of BM. There are many equiaxed dimples on the tensile fracture surface, and the joint mainly presents the characteristic of ductile fracture.

The oxidative coupling of methane over lithium modified proton-conducting catalysts irradiated by microwaves has been studied. Compared with protonconducting catalysts, lithium addition to proton-conducting catalysts resulted in changes in product species and product selectivities, favoring the production of C2 compounds.