摘要：friction stir welding（FSW） is a solid state joining technique developed to join high strength aluminum alloys and various ceramic reinforced metal matrix composites（MMCs）.FSW produces sound welds in MMCs without any deleterious reaction between reinforcement and *** present work focused on the effect of FSW parameters on the tensile strength of Al-B4C composite *** central composite design of four factors and five levels was used to control the number of experiments.A mathematical model was developed to analyze the influence of FSW *** results indicated that the joint fabricated using rotational speed of 1000 r/min,welding speed of 1.3 mm/s,axial force of 10 kN and the reinforcement of 12% showed larger tensile strength compared with the other *** developed model was optimized to maximize the tensile strength using generalized reduced gradient *** metallographic analysis of the joints showed the presence of various zones such as weld nugget（WN） zone,thermo mechanically affected zone（TMAZ） and heat affected zone（HAZ）.The substantial grain refinement of aluminum matrix as well as significant size reduction of B4C particles was observed in the weld *** was plastically deformed,thermally affected and exhibited elongated aluminum grains.

摘要：The joining of a 6-mm thickness Al 6061 to Stainless steel 304 has been performed by solid state welding. A selection method of optimum friction welding condition using neural networks is proposed. The data used for analyses are the friction stir welding condition, the input parameters of the model consist of welding speed and tool rotation speed. The outputs of the ANN (Artificial Neural Network)model includes resulting parameters, namely, maximum reached temperature,and heating rate for both aluminum alloy 6061 and stainless steel 304 during friction stir welding *** results of analysis suggest that the proposed method is an effective one to select an optimum welding *** performance of the ANN model was achieved. The combined influence of welding speed and tool rotation speed on the maximum reached temperature and heating rate for both aluminum alloy 6061and stainless steel 304 friction stir welding was simulated. A comparison was made between the output of the ANN program and finite element model. The calculated results were in good agreement with that of finite element model.

摘要：AA5083 friction stir welds were produced using systematic experimental design, the process forces and heat input with varying parameters were studied. Helpful empirical models were developed in designing friction stir welding （FSW） tools and FSW welders. These models may be further helpful for making process parameter choice for this sort of alloy, defining welding program and control of process parameters by using computer numerical control friction stir welding welders. The results show that tool rotational speed, welding speed and tool shoulder diameter are most significant parameters affecting axial force and heat input, while longitudinal force is significantly affected by welding speed and probe diameter.

摘要：Aluminium alloy（AA） 2024 is an important engineering material due to its widespread use in the aerospace industry. However, it is very prone to corrosion attack in chloride containing media. In the present investigation, AA2024 aluminium alloy rolled plates of 5 mm in thickness were friction stir welded. Corrosion performances of the specimens were evaluated by conducting salt fog tests in Na Cl solution at different p H values, chloride ion concentrations and spraying time. In addition, an empirical relationship was established to predict the corrosion rate of friction stir welds of AA2024 aluminium alloy. A central composite rotatable design including three factors and five levels was used to minimize the number of experiments. Response surface methodology（RSM） was used to develop the relationship. The corrosion rate decreased under neutral p H conditions. The corrosion rate increased in acidic and basic conditions. It was also found that the corrosion rate decreased with the increase of spraying time, but the corrosion tended to be uniform with the increment of time and with the increase in the chloride ion concentration, and the corrosion rate increased in the salt spray corrosion test.

摘要：The extruded AZ61A magnesium alloy plates of 6 mm thickness were butt welded using friction stir welding（FSW） *** corrosion behavior of the welds was evaluated by conducting immersion test in NaCl solution at different pH value,immersion time and chloride ion *** empirical relationship was established incorporating pH value,immersion time and chloride ion concentration to predict the corrosion rate of friction stir welds of AZ61A magnesium alloy at 95% confidence ***-factor,five-level central composite rotatable design was used to minimize the number of experimental *** surface method was used to develop the *** results show that the corrosion resistance of AZ61A magnesium alloy welds in the alkaline solution is better than that in the acidic and neutral solutions,moreover,low corrosion rate is found at low concentrated solution and longer exposure time,and the corrosion morphology is predominantly influenced by the distribution of β-phase.