The solidification cracking behavior in laser welds of steel/copper dissimilar metals was systematically investigated. T2 copper and SUS304 stainless steel were used the study. results showed that occurrence synergistic effect ? phase liquation, inclusions composition segregation. During welding process, liquation grain boundaries substantially reduced cohesion between adjacent grains, as well ...

In this work, a welding solidification crack sensitivity test platform was established to study the effect of wire feeding speed (WFS) on during cold metal transfer (CMT) for AA6061 aluminum alloy. The results show that as WFS increased from 4 m/min 5.5 m/min, cracks also increased. With further increase in value WFS, decreased and eventually ceased exist. A new perspective microstructure propa...

The low cycle fatigue response of a single crystal γ′-containing CoNi-base superalloy has been investigated in air and vacuum at 950 °C. performance is demonstrated to be similar the 1st-generation Ni-base AM1. Fracture surface imaging cross-sections on both alloys reveal that oxidation-assisted cracking responsible for crack initiation air. improves under as transitions internal casting pores ...

This study presents mechanisms of the evolution a narrowed region in weld pool center during deep penetration laser beam welding. In numerous numerical studies presented this study, it was also found that local reduction size can cause detrimental effects on melt flow behavior and resulting properties welds. A particularly large influence effect identified three aspects. First, variation solidi...

Utilisation of additive manufacturing (AM) for the fabrication Ni-based alloys has seen a massive uptake in both academic and commercial institutions. However, processing traditional superalloys through AM encountered numerous cracking issues. The primary forms include solidification, solid-state liquation mechanisms. Many these are influenced by compositions, with certain systems showing impre...

The directional solidification of the transparent binary alloy succinonitrile-poly(ethylene oxide) was studied in an experiment in which solidification speeds of about 2 mm/sec could be reached without loss of the linear temperature gradient. The low diffusivity of the polymer solute allowed the study of the dynamics of rapid solidification using an optical microscope. For both normal and doubl...

As with the consolidation time, the cooling rate applied during the solidification stage of the composite processing cycle influences the total processing cycle time, as well as the mechanical performance. By controlling the solidification rate, changes in the matrix morphology and crystallinity can be achieved, and hence different mechanical properties may be obtained. Control of the solidific...

This paper presents an eddy-current-based technique for imaging the solidification of molten metal inside a metal pipe. This technique is motivated by the fact that the ac (alternating current) impedance seen from a solenoid placed outside the pipe is dependent on the distribution of the solidification inside the pipe provided that the ac frequency is properly chosen and the overall thickness o...

Thin amorphous Ge films on glass substrates are irradiated by single picosecond ~ps! laser pulses and the induced melting and solidification process is followed by means of real-time reflectivity measurements with ps resolution using a setup based on a streak camera. Due to the excellent time resolution achieved in single exposure, the recalescence process occurring upon solidification can be c...