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For glue pouring under complex working conditions, such as multiple gaps and multiple points, it is difficult to meet complex spatial operations due to equipment limitations. Manual glue pouring is usually used, which has the problems of low efficiency, uneven glue pouring, and poor consistency. For this reason, this paper adopts a collaborative six-axis robot with friendly human-computer interaction, safety, and reliability. According to the characteristics and technological process of the two-component thermal conductive adhesive, a flexible pouring device composed of a robot, a sealed barrel, a control valve, a mixing tube, and a fixed bracket is designed. The colloid in the barrel is \"squeezed\" into the control valve by compressed air. After opening the valve, the two-component glue is evenly mixed in the mixing tube. The glue pouring path and amount can be accurately controlled by programming, thus eliminating the manual glue mixing and pouring process, avoiding the inconsistency caused by manual operation, and greatly improving the glue pouring efficiency.

The impellers of centrifugal pumps are highly susceptible to the latent damage of corrosion and cavitation after long periods of transporting chemical fluids. To enhance the structural integrity and effective lifespan of impellers, this study applied mold flow analysis to the design of gating systems for 17-4PH stainless steel enclosed impellers. Our objective was to eliminate shrinkage and porous defects common in investment casting. We adopted various bottom, side, and top pouring systems with different pouring parameters to examine the behavior of the molten metal flow and solidification in the mold cavity. We designed a pressurized gating system with specific gating ratio to achieve a stable flow velocity at in-gates. Physical sensors preset in the interior of the cavity were also used to detect thermodynamic behavior and analyze phase changes during casting simulations. The probability of shrinkage defect formation was assessed using the retained melt modulus (RMM) and the Niyama criterion. Experiments and nondestructive inspections show that optimizing the design of the gating system prevented surface shrinkage and interior defects. The improvements also reduced post-processing time and costs, increased yields, and enhanced casting quality.

Ceramic particulate embedded aluminum metal matrix nanocomposites (AMNCs) possess superior mechanical and surface properties and lightweight features. AMNCs are a suitable replacement of traditional material, i.e., steel, to make automotive parts. The current work deals with developing Si3N4 strengthened high strength AA7068 nanocomposites via novel ultrasonic-assisted stir casting method advanced with bottom pouring setup in the proportion of 0.5, 1.0, 1.5, and 2 wt.%. Planetary ball milling was performed on a mixture of AA7068 powder and Si3N4 (in the proportion of 3:1) before incorporation in aluminum alloy melt to avoid rejection of fine particles. Finite element scanning electron microscope (FESEM), Energy dispersive spectroscopy (EDS), X-Ray diffraction (XRD), and Elemental mapping techniques were used in the microstructural investigation. Significant grain refinement was observed with increasing reinforcing content, whereas agglomeration was found at higher weight %. Hardness, Tensile strength, ductility, porosity content, compressive strength, and impact energy were also examined of pure alloy and each composite. Improvement of 72.71%, 50.07%, and 27.41 % was noticed in hardness value, tensile strength, and compressive strength, respectively, at 1.5 weight % compared to base alloy because of various strengthening mechanisms. These properties are decreased at 2 wt.% due to severe agglomeration. In contrast, nanocomposite’s ductility and impact strength continuously decrease compared to monolithic AA7068. Fracture analysis shows the ductile and mixed failure mode in alloy and nanocomposites.

Due to construction conditions and other limitations, the ultra long basement structure often adopts a layered pouring method for different structural parts. However, excessively long structural dimensions can lead to significant shrinkage deformation and temperature difference deformation of concrete, resulting in asynchronous shrinkage deformation between concrete poured at different stages. These deformations are constrained by structural components poured at different stages, resulting in significant shrinkage stress within the concrete, leading to severe tensile cracking and ultimately forming cracks of varying lengths. In order to prevent concrete cracking caused by shrinkage and temperature changes in ultra long concrete structures, it is possible to strengthen control from the aspects of structure, materials, construction technology, etc. Currently, the most direct and effective way is to apply prestress to the structure. Through finite element analysis, according to the general construction process, the continuous pouring length of the wall needs to be limited to below 12m to ensure no risk of cracking, but it will greatly increase the construction period. This article takes measures from both material and structural aspects to apply pre-stress to the wall to offset the tensile stress that occurs later, thereby ensuring that the stress in the wall is lower than the tensile strength of the concrete, effectively reducing the risk of cracking. This technology has been applied for the first time in engineering, achieving nearly 70 meters of wall without cracks, verifying its feasibility.

Sand-casting is a well established primary process for manufacturing various parts of A356 alloy. However, the quality of the casting is adversely affected by the change in the magnitude of the control variables. For instance, a larger magnitude of pouring velocity induces a drop effect and a lower velocity increases the likelihood of cold-shut and mis-run types of defects. Similarly, a high pouring temperature causes the formation of hot tears, whereas a low temperature is a source of premature solidification. Likewise, a higher moisture content yields microcracks (due to gas shrinkages) in the casting and a lower moisture content results in the poor strength of the mold. Therefore, the appropriate selection of control variables is essential to ensure quality manufactured products. The empirical relations could provide valuable guidance in this regard. Additionally, although the casting process was optimized for A356 alloy, it was mostly done for a single response. Therefore, this paper aimed to formulate empirical relations for the contradictory responses, i.e., hardness, ultimate tensile strength and surface roughness, using the response surface methodology. The experimental results were comprehensively analyzed using statistical and scanning electron microscopic analyses. Optimized parameters were proposed and validated to achieve castings with high hardness (84.5 HB) and strength (153.5 MPa) with minimum roughness (5.8 µm).

Aluminum alloys bears great importance and has found extensive usage area in industry especially in automotive. Ease of casting into complex shape favors their usage. The production method of these alloys has been crucial to obtain the required mechanical and physical properties since their susceptibility to form defects in the form of oxides and various defects is considerably elevated. As high magnesium and copper containing aluminum alloys tends to increase defect formation, in order to improve the overall quality of cast parts, effective melt treatment and optimal pouring processes are essential. This study focuses on the effect of degassing bubble size in melt treatment and vertical versus tilt pouring techniques at casting stage. We evaluate three melt treatment parameters: no degassing, small bubble degassing, and large bubble degassing. The pouring techniques as tilt angle application and vertical pouring have been examined. Under various pouring conditions, the mechanical characteristics of T6 heat-treated custom composition AlMg7Cu2 alloys are compared. Alloying decision has been taken to incorporate as much defect as possible to capture effects of defects due to melt treatment and pouring conditions. Computed tomography scans, SEM analyses of fracture surfaces, and evaluations using optical microscopy have been performed for quality assessments. Basic comparison of tensile testing with CT scans have been provided. Variation of properties at different bubble size and pouring conditions have been provided. The findings emphasize the significance of using tilt pouring with lower hydraulic jump and less turbulence in metal melt flow in mold filling. Moreover, reducing bubble size during degassing has also been found crucial and highly effective in order to achieve consistent mechanical characteristics.

In practical engineering construction, differences in time intervals during concrete pouring arise due to issues in concrete quality control and construction procedures, thereby affecting the mechanical and durability properties of concrete. This study conducted compressive strength tests, splitting tensile strength tests, and natural immersion tests to investigate the influence of time intervals in layered pouring on the mechanical strength and chloride ion concentration distribution of staged pouring concrete. Additionally, the study elucidated the mechanism by which pouring interval time affects the mechanical properties and resistance to chloride ion erosion of staged pouring concrete at the microstructure level. The results indicate that compared to ordinary concrete specimens, the splitting tensile strength of staged pouring concrete demonstrates a continuous decrease with increasing pouring interval time. The most significant splitting tensile strength decrease occurred at a 24 h interval. The compressive strength of staged pouring concrete initially decreases and then increases with increasing pouring interval time. At a pouring interval time of 12 h, the compressive strength of staged pouring concrete decreased the most. Results from the natural immersion tests demonstrate that chloride ion concentrations at the bonding interface and on both sides of staged pouring concrete increase continuously with the extension of pouring interval time. The chloride ion concentration at the bonding interface is consistently higher than that on both sides, and the difference between them decreases with increasing diffusion depth. The chloride ion concentration difference ΔC was proposed to evaluate the influence of bonding interface performance on chloride ion concentration, which decreases to varying degrees with increasing depth. The findings of this study can provide guidance for the research on the mechanical properties and durability of staged pouring concrete in practical engineering construction, as well as for engineering protective measures.

The effects of different clay addition amounts and zircon powder contents on the properties of steel-pouring brick were studied using bauxite particles, sintered mullite powder, and other materials as the main raw materials. The results showed that with the decrease of clay content, the bulk density of the samples changed slightly, but the cold modulus of rupture, compressive strength, hot modulus of rupture, and high-temperature volume stability were improved; the addition of zircon powder did not significantly change the basic properties, such as the bulk density of the brick, but significantly increased the high-temperature flexural strength. Therefore, under the addition of 5 wt.% clay and 1.5 wt.% zircon powder were used for the application. The results show that samples with this formula have good performance, and the surface of the cast steel is smooth. Therefore, the optimization of the mullite steel-pouring brick formula can adopt the strategy of the synergy effect of clay and zircon to improve its comprehensive performance.

This paper uses Midas Fea simulation software to analyze the hydration heat of a suspension bridge anchorage mass concrete construction without cooling water. According to specific boundary conditions and convection coefficients, the concrete heating process and cooling process are simulated. Analyze the influence of surface air convection coefficient on the surface tensile stress of the cast layer, and the influence of the pouring interval on the interlayer stress of the anchor block, and the temperature difference between the inside and outside of the concrete when the anchor block is layered. It is found that reducing the surface convection coefficient of the pouring layer can effectively improve the stress condition, and the pouring interval has little effect on the stress.

Currently, workers in sand casting face harsh environments and the operation safety is poor. Existing pouring robots have insufficient stability and load-bearing capacity and cannot perform intelligent pouring according to the demand of pouring process. In this paper, a hybrid pouring robot is proposed to solve these limitations, and a vision-based hardware-in-the-loop (HIL) control technology is designed to achieve the real-time control problems of simulated pouring and pouring process. Firstly, based on the pouring mechanism and the motion demand of ladle, a hybrid pouring robot with a 2UPR-2RPU parallel mechanism as the main body is designed. And the equivalent hybrid kinematic model was established by using Eulerian method and differential motion. Subsequently, a motion control strategy based on HIL simulation technique was designed and presented. The working space of the robot was obtained through simulation experiments to meet the usage requirements. And the stability of the robot was tested through the key motion parameters of the robot joints. Based on the analysis of pouring quality and trajectory, optimal dynamic parameters for the experimental prototype are obtained through water simulation experiments, the pouring liquid height area is 35–40 cm, the average flow rate of pouring liquid is 112 cm3/s, and the ladle tilting speed is 0.0182 rad/s. Experimental results validate the reasonableness of the designed pouring robot structure. Its control system realizes the coordinated movement of each branch chain to complete the pouring tasks with different variable parameters. Consequently, the designed pouring robot will significantly enhance the automation level of the casting industry.