The conductive oxide impact on Aluminum alloy of YAG pulse laser welding
Few articles are reported about conductive oxide impacting on Aluminum alloy of Nd: YAG pulse laser welding at present. Therefore, this paper takes one typical Aluminum alloy as laser welding samples. Through SEM (scanning electron microscope) microscopic analysis and contrast, the comparative study between on with and without surface conductive oxidation impacting on laser welding samples have been conducted. The results show that the laser welding process parameters are needed, but the conductive oxide will bring no destructive effect on laser welding. Accordingly for this reason, it is thought that the conductive oxide will not bring substantial effect on Aluminum alloy of Nd: YAG pulse laser welding.
Study on Laser Welding of 1420 Aluminum-lithium Alloy
The reasons causing main defects of 1420 aluminum-lithium alloy were analyzed.The influences of the laser welding process parameters on the formation and welding were elaborated.The aluminum-lithium alloy development and the trend of the future were projected.
Experimental investigation of the geotechnical properties and microstructure of lime-stabilized saline soils under freeze-thaw cycling
Abstract The Song-Nen Plain in northeastern China holds one of the three largest expanses of soda saline-alkali soil in the world. Due to its disadvantageous geotechnical properties, the saline soil in this area is unable to meet the needs of construction projects. This study evaluates the stabilizing effect of adding lime to such soils. Specifically, it investigates how the physicochemical and mechanical properties and microstructure of soda saline-alkali soil are altered by lime and how these changes are affected by both freeze-thaw cycling and the duration of curing. The results reveal that adding lime to saline soil transforms clay particles into sand and silt particles and causes the pore size distribution (PSD) to become bimodal, with small-pore and macropore populations. An increase in lime content leads to an increase in the unconfined compressive strength (UCS) but a gradual decrease in both the cation exchange capacity (CEC) and plastic index. Freeze-thaw cycles break up coarse particles and aggregate finer particles, increasing the diameter of macropores and decreasing the USC; however, the effect on specimens with >9% lime is negligible. It is further shown that the geotechnical properties of the soil change immediately after the addition of lime, indicating that the cation exchange reaction takes place very quickly. Furthermore, the pozzolanic reaction leads to an increase in the percentage of sand-sized particles and a decrease in porosity after 28 days of curing. Overall, these results indicate that it is feasible to use lime to improve the engineering properties of soda saline-alkali soil in this area.