Enhanced Fluidity of ZL205A Alloy with the Combined Addition of Al–Ti–C and La

The effects of Al–Ti–C and La on the fluidity of a ZL205A alloy after separate and combined addition were studied by conducting a fluidity test. The fluidity of the ZL205A alloy first increased and then decreased with the increasing addition of Al–Ti–C and La; it peaked at 0.3% and 0.1% for Al–Ti–C and La, respectively. The combined addition of Al–Ti–C and La led to better fluidity, which increased by 74% compared with the base alloy. The affecting mechanism was clarified through microstructure characterization and a DSC test. The heterogeneous nucleation aided by Al–Ti–C and La, the number of particles in the melt, and the evolution of the solidification range all played a role. Based on the evolution of the fluidity and grain size, the optimal levels of Al–Ti–C and La leading to both high fluidity and small grain size were identified.

A Predictive Model for the Anisotropy Index of Semi-Coke Derived from the Properties of Colombia's Eastern Cordillera Coals

This study developed a theoretical model for the determination of the Coke Anisotropy Quotient (CAQ) of semi-coke from the properties of its precursor coal. This is an useful parameter to define the resistance and reactivity of semi-coke in the blast furnace. For 36 semi-coke samples, a textural analysis was performed alongside a fluidity test to determine the real CAQ. The main textures observed were: isotropic and circular for high volatile bituminous coals (HVB); lenticular and fine ribbons for the medium volatile bituminous coals (MVB); and medium and thick ribbons for the low volatile bituminous coals (LVB). The CAQ varied in a range from 1 to 11. A principal component analysis (PCA) and multiple regression allowed to discriminated the importance of certain coal properties, in determining the CAQ to be recognized and to estimate parameters of the mathematical model. The statistical analysis suggested that CAQ can be best predicted from the fluidity, volatile matter, and Ro of the parent coals. The veracity of this model result was then tested using a second dataset from Poland. This work optimizes the usefulness of standard datasets in the prediction of CAQ's offering a means of quality control that could be implemented in Colombian coke production.

Fluidity Test of Aluminum Alloy

A die to estimate the thickness of the thinnest fin of a heat sink made by die casting aluminum alloys is proposed. The die consists of a taper-off thin fin and a cooling area. It was shown that this die can be used to estimate the smallest fin thickness of different aluminum alloys.

Slurry and Technology Optimization for Grouting Fissures in Earthen Sites with Quicklime

Shrinkage differentiation and the need for multiple replenishments of slurry after fissure reinforcement are key problems for the grouting reinforcement of fissures in earthen sites. In this study, quicklime was mixed with 1.5% SH binder, clay, and fly ash in different proportions to prepare nine different mixtures and water-cement ratios of SH-(CaO + C + F) slurry. An expansibility test was performed, and based on the results, four groups of slurry were selected for a fluidity test. Ultimately, three different water-cement ratios were considered, and the mixing ratio of 3 : 2 : 5 was determined to produce the optimum slurry. The curing age was optimized according to the intensity and tensile and flexural strengths of the concretion. The selected slurry and curing age were then applied to testing traditional grouting technology and optimized grouting technology (i.e., microlime piles in the fissure) in fissure grouting field experiments. The acoustic wave, penetration resistance, and infrared thermal imaging results after fissure grouting were used to develop a preliminary explanation for the related mechanisms of slurry swelling, hardening, and lime pile compaction. The results showed that the combination of the preferred slurry and optimized grouting technology help address the problems of shrinkage differentiation on both sides of the fissure and need for multiple replenishments of the slurry after grouting.

Removal of Oxide Inclusions in Aluminium Scrap Casting Process with Sodium based Fluxes

The investigation of Oxide Inclusions removal in aluminium scrap casting process with sodium based fluxes has been carried out. The purpose of this research is to investigate the effect of Na2SO4 and NaCl based fluxes addition onto the fluidity and microstructure of aluminium product. The alloy which is used in this investigation is Al-Si which mixed with metal scrap using gravity casting method. The variation of melting temperature in this investigation are 700°C, 740°C, and 780°C. In this research, material characterization was determined using DSC, EDAX, XRD, and fluidity test. The results show that the number of oxide inclusions decrease as the addition of 0,2% wt. flux, and completly removed after the addition of 0,4% wt. flux. The highest fluidity and tensile strength was obtained after the addition of 0,4% wt. flux. at 740°C.

FTA analysis of the failure in the horizontal fluidity test

The purpose of the paper was to evaluate the probability of the top event in the fluidity test by Fault Tree Analysis (FTA). One of the important tests used in the foundry practice is the test of the fluidity. Fluidity is the ability of the molten metal to fill the cavity of the molds and create a cast. The AlSi10MgMn (EN 1706) alloy with 5 or 10.54 % of silica was the experimental material. The melted alloy was cast into "horizontal" three-channel mold to test its fluidity. The pouring temperatures were between 605 and 830 °C. In some cases, the experiment was not successful, for a some reasons. This fact led to a waste of time, energy, potential risk of accident, confusion among participants, especially "beginners" founders and became an impulse for the analysis of creation and possible events of fault for the fluidity test using the FTA. It has been found that for the probability of the top event in examined process was disproportionately high (0.29824). The Monte Carlo method was used for the simulation of the effect of decreasing the probability of basic events on the probability of the top event – the fault of the fluidity test.

Influence of Acid/Ether-Ratio on Composition and Dispersive Property of Polycarboxylic Type Water Reducers

Polycarboxylic type water reducers were synthesized at different molar ratios of acrylic acid to methyl-allyl polyethylene glycol2400 (acid/ether-ratio). Influence of the acid/ether ratio on its composition and dispersive property were studied by means of Gel Permeation in Chromatography (GPC) and fluidity test of cement paste. The GPC analysis results showed that the average molecular weight and polydispersity were increased with the increase of acid/ether-ratio, but the polymerization degree should be no longer increased as which reached to a certain value, the excessive small-monomers would be self-polymerized when macro-monomers had been consumed. As the final product of polymer at an acid/ether ratio of 5:1, was composed of un-reacting macro monomer (about 6%) and the copolymer of water reducers (about 92%) and the copolymer of small monomers (about 2%). The result of fluidity of cement paste showed that the acid/ether-ratio also influenced the dispersive property to different cement, its ability would be bad if at the ratio of 2:1, then the property of dispersive and fluidity retaining should be all well if at 3.5:1, and the beginning dispersive ability might be high but the ability of fluidity retaining be low as the ratio was beyond 4.5:1.