Numerical Simulation and Optimization of Indirect Squeeze Casting Process

Abstract

In order to optimize the process of indirect squeeze casting, computer aided engineering (CAE) technology was used to predict casting defects. Taking an adapter ring casting as an example, its 3D-model was established and its casting process was designed. The results indicate that, for indirect squeeze casting, when the liquid metal injects to mold cavity by casting system, temperature of liquid metal has dropped and started to solidify. At the same time, the runner has begun to solidify. If the cross-section of runner is too small, the runner pressure has not passed the casting to produce the effect of feeding, therefore this problem will lead to casting defects such as shrinkage cavity. As a result, full consideration should be given to the feeding effect of the runner in mold design. Simulation software can be used to simulate the temperature field of casting filling and solidification to design the runner reasonably.

Crystallization and Phase Transformations of Aluminum (Oxy)hydroxide Polymorphs in Caustic Aqueous Solution

“…Aluminum is the most common metal and the third-most abundant element in the Earth’s crust. − As a result, aluminum (oxy)­hydroxide polymorphs, such as gibbsite (α-Al­(OH) 3 , sometimes designated as γ-Al­(OH) 3 ), bayerite (β-Al­(OH) 3 , sometimes as α-Al­(OH) 3 ), nordstrandite (Al­(OH) 3 ), doyleite (Al­(OH) 3 ), boehmite (γ-AlOOH), and diaspore (α-AlOOH) are abundant minerals in soils and dominate aluminum ores such as bauxites. Similar to other types of metal hydroxide materials such as layered double hydroxides (LDHs), − various aluminum (oxy)­hydroxide phases have been deployed widely as adsorbents, fire retardants, coatings, catalysts, and luminescence materials. − These phases are also important precursors to various alumina products such as α-, γ-, δ-, θ-, and χ-Al 2 O 3 . ,− Understanding the crystallization and phase transformation pathways of the aluminum (oxy)­hydroxide polymorphs is thus important to geochemistry, environmental science, energy storage, catalysis, biomedicine, industrial processing, and even nuclear waste treatment. ,− In particular, various aluminum (oxy)­hydroxides, which dominate certain high-level tank waste sludges, are problematic due to their much lower solubility and variable phase transformation properties. ,,− …”

Highly efficient photocatalytic organic dyes degradation based on 1D magnetic Bi2Fe4O9/C@AgBr composite

“…Thence, introducing magnetism to form magnetic photocatalytic materials can maintain the catalytic activity of composites and accelerate their separation from the reaction mixture. [ 44–47 ] Furthermore, the 1D structure could transfer photogenerated carries to reaction centers effectively and solve the carrier spatial localization problems. [ 48 ] C with high electrical conductivity has been widely used in the field of microwave absorption and photocatalysis.…”

Mechanical and tribological properties of polytetrafluoroethylene reinforced by nano-ZrO2: Molecular dynamic simulation

“…With the continuous progress of nanotechnology and computer technology, molecular dynamic (MD) simulation has gradually matured and moved toward application. 24,25 This method not only obtains the atomic motion trajectory but also observes the microscopic details of the atomic motion. It is a powerful supplement for theoretical calculation and experimental research.…”