In steels the dependence of ambient temperature microstructure and mechanical properties on solidification rate is not well reported. In this work we investigate the microstructure and hardness evolution for a low C low Mn NbTi-microalloyed steel solidified in the cooling rate range of 1-50 Cs-1. The maximum strength was obtained at the intermediate solidification rate of 30 Cs-1. This result h...

Solidification occurs in several material processing methods, such as in casting, welding, and laser additive manufacturing of metals, and it controls the nanoand microstructures and the overall properties. Recent advances in experimental and computational modeling techniques have made it possible to more e ectively study atomistic and microscale mechanisms that control the solidification struc...

Ti-based metal matrix composites (MMCs) represent a material class with highly desired performance for the aerospace industry, but implementation has been hindered by poor processability. It is now being realised that MMCs can be formed in situ through exploitation of rapid cooling rates laser powder bed fusion, and targeting invariant reaction compositions to minimise propensity solidification...

During the welding of 690 nickel-based alloy, solidification cracking (SFC) and ductility-dip (DDC) easily forms, which has a negative effect on quality welded joints service life. The present study examined effects heat input cladding layers SFC DDC, as well their formation mechanism. microstructure observation, elemental distribution, Varestraint test were carried out. results show that DDC f...

In this paper, a complete three-dimensional numerical model of mold filling and solidification of steel ingots is presented. The risk of powder entrapment and defects formation during filling is analyzed in detail, demonstrating the importance of using a comprehensive geometry, with trumpet and runner, compared to conventional simplified models. By using a case study, it was shown that the simp...

Compositionally graded bulk materials of organic polymer blends were prepared by using nonequilibrium self-organization processes with a uniaxial thermal gradient (Bridgman method). The Bridgman method was firstly applied to prepare two kinds of polymeric compositionally graded materials: a polymer/low molecular weight additive system (poly(e-caprolactone) (PCL)/ 4,49-thiodiphenol (TDP)) and a ...

Variant Stochastic cracking is a significantly more resilient approach to adaptive indexing. It showed [1]that Stochastic cracking uses each query as a hint on how to reorganize data, but not blindly so; it gains resilience and avoids performance bottlenecks by deliberately applying certain arbitrary choices in its decision making. Therefore bring, adaptive indexing forward to a mature formulat...

_____________________________________________________________ Different catalysts based on Y-zeolite, ZSM-5 and amorphous kaolin were prepared and characterized. The catalytic cracking of 1,3,5-triisopropylbenzene (1,3,5-TIPB), 1,4diisopropylbenzene (1,4-DIPB) and n-dodecane were used to investigate the effect of catalyst nature on the catalytic performance. Cracking the largest molecule (1,3,5...

The varestraint cracking test was carried out to assess the hot cracking tendency of alloy 800 at different welding conditions and augmented strain levels. The test results revealed that the hot cracking susceptibility of alloy 800 increases with increasing the heat input and augmented strain levels. This emphasizes the role of constraint either internally induced or externally applied to the w...