Injection Speed Research Articles

A Study on the Architecture of Artificial Neural Network Considering Injection-Molding Process Steps.

In this study, an artificial neural network (ANN) was established to predict product properties (mass, diameter, height) using six process conditions of the injection-molding process (melt temperature, mold temperature, injection speed, packing pressure, packing time, and cooling time) as input parameters. The injection-molding process consists of continuous sequential stages, including the injection stage, packing stage, and cooling stage. However, the related research tends to have an insufficient incorporation of structural characteristics based on these basic process stages. Therefore, in order to incorporate these process stages and characteristics into the ANN, a process-based multi-task learning technique was applied to the connection between the input parameters and the front-end of the hidden layer. This resulted in the construction of two network structures, and their performance was evaluated by comparing them with the typical network structure. The results showed that a multi-task learning architecture that incorporated process-level specific structures in the connections between the input parameters and the front end of the hidden layer yielded relatively better root mean square errors (RMSEs) values than a conventional neural network architecture, by as much as two orders of magnitude. Based on these results, this study has provided guidance for the construction of artificial neural networks for injection-molding processes that incorporates process-stage specific features and structures in the architecture.

Injection Flow Rate Threshold Preventing Atypical In-Cavity Pressure during Low-Pressure Powder Injection Molding

Controlling injection parameters is paramount when it comes to producing high-quality green parts using powder injection molding. This work combines experimental and numerical approaches to study the impact of injection parameters on mold in-cavity pressure and on the overall quality of green parts produced by low-pressure powder injection molding. The properties of two low-viscosity feedstocks (formulated from a water-atomized stainless-steel powder and wax-based binder system) were measured and implemented in an Autodesk Moldflow numerical model to quantify the molding pressures, which were finally validated using experimental real-scale injections. The results confirmed that an increase in mold temperature, an increase in feedstock temperature, and a decrease in solid loading decrease the mold in-cavity pressure, which was correlated with the feedstock viscosity. As a key result, real-scale injections confirmed that a minimum flow rate was required to avoid atypical high in-cavity pressure leading to several visual defects such as weld lines, flow marks, cracks, sinks, and incomplete filling. Due to differences in its thermal transfer properties, this flow rate threshold value decreases as the feedstock solid loading increases. For injection speeds higher than this value, the injection pressure measured experimentally was linearly correlated with the injection flow rate.

Distribution and reinforcement effect of carbon fiber at the interface in injection welding of polyamide 6 composites

AbstractTo meet the lightweight production requirements of automobiles and achieve high strength, reinforced thermoplastic composite materials are gradually replacing metal materials. Injection molding is the preferred manufacturing method to enable the production of complex‐shaped parts, facilitate production, and reduce costs. In this study, carbon fiber (CF) was added to the commonly used resin‐reinforcing material, polyamide (nylon) PA6, to create a CF‐reinforced thermoplastic composite (polyamide 6 [PA6]/CF) that was welded using injection molding. This study not only investigates the impact of different welding conditions on shear strength but also discusses the sequence of welding. Achieving 85% of the shear strength of the PA6 base material under ideal circumstances. The CF distribution and reinforcement mechanism were analyzed by observing the connection interface and cross section using a polarizing microscope and a scanning electron microscope. When PA6/CF was used as the secondary molded body, the welding results were better. The addition of CF had a significant strengthening effect on the strength of the PA6 injection welding.Highlights Carbon fiber‐reinforced thermoplastic composite materials were prepared, and welding with PA6 was achieved using the injection molding method. The optimal welding parameters were determined by varying the mold, injection speed, injection temperature, and order of injection. The maximum welding shear strength reached 85% of the base material shear strength. The positive effect of specific fiber distribution on welding strength was analyzed by observing the interface using a scanning electron microscope and a polarizing microscope. This study provides valuable insights into the optimization of welding processes for carbon fiber thermoplastic composite materials, offering possibilities for connecting dissimilar materials with poor compatibility.

Flushing effect of micro-bolus pulse injection and its potential impact on peripheral veins under hemostasis.

To explore the feasibility of using micro-bolus pulse injection method to reduce the dilution effect of pipeline on high concentration injection, and to understand low liquid volume bolus injection based on low injection speed. Using a programmable pulse injection pump, a 25-cm - long pipeline containing water-soluble fluorescent agent was flushed using different volumes of bolus, and the time spent for the complete disappearance of the fluorescent agent was recorded to evaluate the flushing efficiency. The finite element simulation of 2-phase flow was carried out using computational fluid dynamics (CFD) technology, and the difference of shear rate and pressure distribution in the vein of pulse injection and direct injection of bolus under hemostasis was compared and simulated. Micro-bolus pulse flushing has advantages in completing perfusion imaging applications, such as small volume imaging agent injection. Compared with non-pulse injection, the effective flushing volume decreases by 49.7%, the average injection speed decreases by 56%, and the maintenance time of high shear rate is shorter when using micro-bolus pulse injection. The impact of micro-bolus pulse injection on the vein can achieve the same or even lower negative effects as other injection methods after increasing the hemostatic distance to 100 mm. In the case of bolus injection requiring high concentration and small volume, such as for radiopharmaceutical dynamic imaging, the application of micro-bolus pulse injection is an effective way to overcome the dilution phenomenon of the imaging agent in the pipeline. During hemostasis, the micro-bolus pulse injection needs to control a longer hemostasis distance to reduce the potential impact on peripheral veins.

Factors affecting the preparation of Cilnidipine nanoparticles

Cilnidipine is a dihydropyridine calcium channel blocker used to improve the neurological outcome following subarachnoid hemorrhage. It belongs to BCS class II drugs that have a low oral bioavailability of 13%, thus preparation as nanoparticles would be expected to improve bioavailability.
 The aim of the study is to prepare Cilnidipine as nanoparticles using different carriers and co-carriers, concentrations, and types.
 Cilnidipine nanoparticles were prepared by a solvent anti-solvent method using different carriers (Soloplus®, Poloxamer 188, PVA cold) with co-stabilizers (PEG200, glycerol) at different ratios.
 Based on the obtained results, formula N4, which included Soloplus in a 1:1:1 weight ratio of drug to the polymer to co-stabilizer, exhibited a particle size of 88.89 nm when stirred at 1000 rpm with an injection speed of 1 ml/min. The polydispersity index (PDI) for this formula was measured at 0.2413. Furthermore, formula N4 demonstrated an impressive 92.2% drug content and an entrapment efficiency (EE) of 95.8%, giving 100% release in 30 min.

Investigation on displacement efficiency and enhance oil recovery performance of CO2 and CO2-chemical additive composite system flooding using LBM simulation

CO2 flooding is a promising EOR method. Chemical additives reduce oil viscosity and CO2-oil interfacial tension. In this study, we propose a multiphase and multi-component model based on the LBM to examine the effectiveness of CO2 flooding and identify the factors that influence its performance. Additionally, we present a novel approach for simulating CO2-chemical additive composite system (CCAS) flooding by modifying fluid interaction parameters and reducing oil viscosity when exposed to chemicals. A comparison was conducted between the CO2 flooding approach and the CO2-chemical additive compound systems. The results show that the force between fluid molecules has a significant impact on interfacial tension and miscibility, affecting the displacement process. The viscosity and injection speed of the displaced fluid play a crucial role in determining the initial momentum and CO2 displacement performance. Additionally, reservoir rock morphology has an impact on the velocity of fluid molecules, and affects the displacement efficiency. The CCAS flooding has the potential to increase oil recovery by 15% compared to using CO2 flooding alone. Optimizing additive concentration, injection timing, and injection rate can further improve oil displacement efficiency by 5%-10%. Valuable theoretical guidance for applying CO2 chemical additives is provided by these research findings.

Optimization of injection parameters of a microemulsion-type oil displacement agent for heavy oil recovery

The conventional viscosity reduction technology through commercial oil-soluble agents for enhanced oil recovery in heavy oil reservoirs has potential safety hazards. In this work, micro-emulsification of heavy oil is proposed as a means of reducing its viscosity for ease of its recovery. The microemulsion-type oil displacement agent was developed, and its performance was characterized by its pseudoternary phase diagram and dynamic light scattering tests. The core tests were used to study the effects of injection volume, injection speed, and subsequent water flooding speed on the oil recovery factors. These results were used to determine the optimal injection parameters. Furthermore, the displacement mechanism for heavy oil was determined based on combined macroscopic and microscopic visual tests. The results showed that the optimal injection volume is 0.15 PV (pore volume), the injection rate is 0.10 ml/min, and the subsequent water flooding rate is 0.20 ml/min. Based on the optimal parameters, the oil recovery efficiency can reach up to 39.83%, which is 25.69% higher than water flooding process. The displacement mechanism of the microemulsion can be divided into three stages. First, when the microemulsion is in contact with the heavy oil, the solubilization occurs spontaneously, and the heavy oil is peeled off from the rock surface. Then, the solvent in the microemulsion interacts with the heavy oil to achieve the viscosity decrease in the heavy oil. Third, during the water flooding process, the viscosity-reduced heavy oil can be emulsified to form oil-in-water emulsion, further realizing the viscosity reduction of heavy oil.

Optimizing of particle accelerated rotor parameters using the discrete element method.

The acceleration capability of a centrifugal jet rotor plays a crucial role in achieving a high injection velocity of powder particles in the centrifugal impact moulding process. In this regard, the focus of this article is on optimization of the runner shape. To this end, the lengths of the first and second acceleration sections (L1 and L2), and the angles between the first and second acceleration sections and between the second and third sections (α1 and α2) are considered as the rotor parameters. Simulations were conducted using multiple discrete elements to explore the influence of multiple input parameters on the response value, and a regression model was established between the parameters and the particle injection rate. The experimental results show that the selected parameters significantly affect the rate of particle injection, and the interactions between the parameters L1 and L2, and between L2 and α2 have the largest effects. The results reveal that applying the optimized parameters improves the particle injection speed by 7.85% when compared to the pre-optimization model. This improvement in the rotor acceleration provides the basis for improving the efficiency of centrifugal impact moulding of metal powders.

Dynamics of a Plasma Cloud Generated by a Compact Coaxial Gun upon Expansion into Vacuum and Large-Volume Background Plasma in an External Magnetic Field

Results of experiments on injection of dense plasma clouds created by a small-scale coaxial generator into vacuum and large-volume background plasma in an ambient magnetic field are presented. The regime of an “infinite” background medium that allows studying the plasma-cloud dynamics on the scale of about one meter in the directions perpendicular and parallel to a quasi-uniform magnetic field is realized on “Krot” plasma device. The dynamics of the diamagnetic cavity appearing upon magnetic-field expulsion by a plasma blob, the electromagnetic noise appearing in the cavity, along with the evolution of plasma-cloud structure during injection and at the stage of its decay, were studied. It is demonstrated that the key properties of the cloud dynamics that are typical of the active space and high-energy laboratory experiments, including complete expulsion of the magnetic field from the cloud and development of the flute instability at its boundary, are reproduced at low injection speed (below 30 km/s) and low plasma energy (on the order of 0.1 J).

Analysis of Fractures and Microstructures on Different Injection Speeds in High-Pressure Die-Casting Magnesium Alloy

In this study, to clarify the unknown physical properties of the Mg-Al-Th-RE alloy, the relationship between the injection conditions and the internal porosities, and the mechanical properties exerted by the solidification microstructure was investigated. The obtained cast samples were investigated using X-ray CT internal measurements, tensile tests, Vickers hardness tests, and solidification microstructure observations. The tensile strength and the elongation at the injection speed of 5.0 m/s were higher than at 2.0 m/s. The number of porosities affected the tensile strength and the elongation even at the same fracture position. In addition, it was confirmed that segregation affected the destruction smaller the porosity size and the greater the variability of porosity. As the injection speed increased, the amount of heat transferred between the molten metal and the wall surface also increased, resulting in quick freezing and solidification. The tensile strength increased at the injection speed of 5.0 m/s because the interface between the scattered primary crystals and eutectic systems was narrow. On the other hand, at the injection speed of 2.0 m/s, the tensile strength decreased because the molten metal was delayed in solidification and dendrite growth became remarkable.

Ultrasound Localization Microscopy for Breast Cancer Imaging in Patients: Protocol Optimization and Comparison with Shear Wave Elastography

Ultrasound localization microscopy (ULM) has gained increasing attention in recent years because of its ability to visualize blood vessels at super-resolution. The field of oncology, in particular, could benefit from detailed vascular characterization, for example, for diagnosis and therapy monitoring. This study was aimed at refining ULM for breast cancer patients by optimizing the measurement protocol, identifying translational challenges and combining ULM and shear wave elastography. We computed ULM images of 11 patients with breast cancer by recording contrast-enhanced ultrasound (CEUS) sequences and post-processing them in an offline pipeline. For CEUS, two different doses and injection speeds of SonoVue were applied. The best injection protocol was determined based on quantitative parameters derived from so-called occurrence maps. In addition, a suitable measurement time window was determined, also considering the occurrence of motion. ULM results were compared with shear wave elastography and histological vessel density. At the higher dose and injection speed, the highest number of microbubbles, number of tracks and vessel coverage were achieved, leading to the most detailed representation of tumor vasculature. Even at the highest concentration, no significant overlay of microbubble signals occurred. Motion significantly reduced the number of usable frames, thus limiting the measurement window to 3.5 min. ULM vessel coverage was comparable to the histological vessel fraction and correlated significantly with mean tumor elasticity. The settings for microbubble injection strongly influence ULM images, thus requiring optimized protocols for different indications. Patient and examiner motion was identified as the main translational challenge for ULM.

Technical note: 3D-printed MRI-compatible syringe pump.

A power injector is typically employed to deliver a contrast agent to a subject (e.g., humans, animals, phantoms) during MRI, but it is costly and cannot inject more than one subject at a time. Conventional syringe pumps housing multiple syringes are typically non-MRI compatible and, thus, should be placed outside the MRI room. To develop the prototype of a cost-effective, easy-to-use, reliable syringe pump that could be deployed inside a clinical MRI bore and operated on during a scan. The MRI-compatible syringe pump (MSP) was designed using Solidworks 3D modeling software and fabricated using a Raise3D Pro2 Printer. The MSP was designed to infuse up to three syringes simultaneously. The injection speed was mainly controlled with different gear sets in the escapement unit and further adjusted by changing the effective hairspring length via a pinch pin. The MSP was evaluated with three gear sets (gear ratios: 0.20:1, 0.56:1, and 1.09:1) and 10 different effective hairspring lengths at each gear ratio. A video was recorded while operating MSP at each injection speed to calculate the volume injection rate of a 5-mL syringe (mL/s). The MSP was operated five times repeatedly at each injection speed, and the mean and standard deviation of the volume injection rate were calculated. The volume injection rates produced by three gear ratios (0.20:1, 0.56:1, and 1.09:1) were 0.209±0.003mL/s, 0.411±0.002mL/s, and 0.625±0.006mL/s, respectively, at the full hairspring length. The injection rates of gear set 1 (gear ratio: 0.20:1) decreased from 0.273±0.001mL/s to 0.245±0.001mL/s with a decrement of 0.003mL/s for 10 different effective hairspring lengths (r=0.997, p<0.001). The injection rates of gear set 2 (gear ratio: 0.56:1) decreased from 0.519±0.003mL/s to 0.469±0.003mL/s with a decrement of 0.006mL/s (r=0.987, p<0.001), and that of gear set 3 (gear ratio: 1.09:1) decreased from 0.779±0.012mL/s to 0.709±0.005mL/s with a decrement of 0.007mL/s (r=0.963, p<0.001). The coefficient of variation in the injection rate measurement was 0.727±0.346%. The MSP is a portable device that can reliably deliver a liquid agent to multiple subjects inside a clinical MRI bore during a scan.

Deep Learning-Enhanced Dual-Module Large-Throughput Microinjection System for Adherent Cells

Despite the rapid development in providing precise delivery of extraneous samples to the vast majority of cells, robotic microinjection is still hindered by cumbersome operations and low throughput in practice. This study presents a new automated microinjection system equipped with two micromanipulators and a deep learning algorithm for cell identification. The introduction of two coordinated micromanipulators based on the same cell handling platform results in a large increase in injection throughput. A deep convolutional neural network, Mask R-CNN, is used to detect and segment stain-free adherent cells, leading to a considerable increase in operational efficiency and subsequent throughput. In the three independent experiments, over 10,000 MC3T3 mouse fibroblast cells are injected to evaluate the injection speed, success rate, and survival rate. Experimental results confirm that our system can inject around 4,000 cells in 1 h with an approximately 60.3% success rate and an 82.0% survival rate. This research’s success will make robotic microinjection a competitive tool in many biomedical applications, such as plasmid DNA transfection. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Note to Practitioners</i> —The motivation of this study is to improve the throughput of cell microinjection, which has become a bottleneck problem hindering the clinical application of microinjection technology. Existing cell microinjection systems typically use only one micromanipulator and rely on manual identification of cells, resulting in a limited ability to process cells for one experimental cycle. This study proposes a novel method that identifies cells through deep learning automatically and uses two micromanipulators simultaneously to improve cell processing capabilities. The problem of manipulating two micromanipulators for nearby cells is formulated as a route optimization problem, which is also suitable for three or more micromanipulators. A deep learning algorithm is used to identify and select cells to increase the processing speed. Experiments are performed to demonstrate that the proposed method can greatly increase the throughput while maintaining satisfactory performance in microinjection.

Physical Simulation of Steam Absorption Characteristics in Horizontal Wells of Super Heavy Oil Reservoir

In the process of dual Horizontal well SAGD development of super heavy oil, the steam absorption balance of upper horizontal steam injection well is an important factor to determine the development effect of SAGD. The factors affecting the steam absorption of upper horizontal wells involve reservoir permeability, steam injection technology, steam injection parameters, etc. The physical simulation method is used to study the influence degree of each specific factor and improvement measures. Based on the similarity criterion, the reservoir scale model is designed and made according to the oilfield prototype, and the simulation experiment is carried out on the steam absorption characteristics and influencing factors along the horizontal wellbore. The experimental results show that the steam injection rate, non condensable gas, the location of the steam injection string and the reservoir permeability have great effects on the steam absorption of the reservoir. The heating uniformity along the horizontal well can be improved by properly increasing the steam injection speed, adding a certain amount of non condensable gas to the steam, and the position of the steam injection string end in the relatively low permeability area of the reservoir. This achievement has a strong guiding significance for improving the steam absorption balance of horizontal wells and improving the development level of dual level SAGD.

PREVENTING HYPOTENSION CAUSED BY SPINAL ANESTHESIA IN NON PREECLAPMTIC PREGNANCIES WITH CAESAREAN SECTION

Introduction. Caesarean method widely used and become popular among pregnant women. In general, this method mostly used regional anesthesia (spinal, epidural and CSE). However, many reports incidence of complication related to spinal anesthesia after the procedure. Maternal hypotension is the most common complication after spinal anesthesia procedure. Therefore, anesthesiologist need to prevent hypotension during spinal anesthesia in caesarean section. Method. The researcher examines several scientific journals from PubMed, BJA, Elsevier, Cochrane Library and BMC research until 10th August, 2023 for abstracts, conference proceedings, and full-text papers that evaluated prevention of hypotension in non-preeclampsia patients undergoing caesarean delivery under spinal anesthesia. In addition, the researchers examine the research conducted during 2016 to 2023. Result &amp; Analysis. The researchers examine 28 scientific article (11.153 parturient) with 6 different methods to prevent hypotension. It was found that vasopressor is widely used in most research with incidence of hypotension varied from 4%-87,4%. IVCU studies reported the incidence of hypotension in 15,3%-43%. Leg Elevation a non-invasive technique studies reported the incidence of hypotension in 33,3-41,4%. Injection speed adjustment methods resulted incidence of hypotension in Fast injection 50 %-75% and Slow Injection in 36,7%-61%. In addition, granisetron methods diluted in normal saline reported the incidence of hypotension in 17,5%-42%. Low dose spinal anesthesia studies reported incidence of hypotension in 0% - 62,9%. Discussion. From all the research that has been reviewed, vasopressor (Phenylephrine), Leg Elevation and low dose spinal anesthesia could become primary options to prevent hypotension during spinal anesthesia in caesarean section since its effective to prevent hypotension, cost effective, and easy to applied in every medical facility.

The Adherence and Outcomes Benefits of Using a Connected, Reusable Auto-Injector for Self-Injecting Biologics: A Narrative Review.

Many biologics are now self-administered by patients at home. A variety of self-injection devices are available, including vials and syringes, prefilled syringes, and spring-driven prefilled pens or auto-injectors. Each has advantages and drawbacks, and different devices suit different patients. For example, some patients have difficulty achieving consistent and successful self-injection due to poor manual dexterity, or experience anxiety at the prospect of self-injection or injection-site pain. These factors can reduce patients' medication adherence and overall experience. Furthermore, while self-injection brings patients many benefits, the proliferation of single-use injection devices has implications for environmental sustainability, including the reliance on single-use plastics, repeated freighting requirements, and need for incineration as hazardous waste. Recently developed, innovative electromechanical auto-injector devices offer technological enhancements over existing devices to overcome some of these issues. Features include customisable injection speeds or durations, consistent rate of injection, electronic injection logs and reminders, and step-by-step, real-time instructions. Indeed, a growing body of evidence points to higher adherence rates among patients using electromechanical devices compared with other devices. Further, with time, the reusability of electromechanical devices may prove to lighten the environmental impact compared with disposable devices, especially as research continues to optimise their sustainability, driven by increased consumer demands for environmental responsibility. This narrative review discusses the differences between prefilled syringes, spring-driven prefilled pens, and electromechanical devices. It also explores how these features may help reduce injection-associated pain and anxiety, improve patient experience, connectivity and adherence, and drive sustainability of biologic drugs in future.

INVESTIGATION OF THE INFLUENCE OF LIQUID FUEL INJECTION RATE ON THE COMBUSTION PROCESS USING KIVA–II SOFTWARE

In this work, the ignition of liquid fuel was studied at various rates of fuel injection into the combustion chamber. The studied processes are described by the following equations: continuity, momentum, energy, k-ɛ turbulence model and others. The computational experiment was carried out using the KIVA-II software. The numerical method is efficient and takes into account various factors such as multistage chemical chain reactions, transfer of momentum, heat and mass by convection, radiation, turbulence, etc. In order to select the optimal parameters of the organization of these processes influence of the heptane injection rate into the combustion chamber on the process of combustion and self-ignition of heptane was studied. The injection rate of heptane varied from 160 m/s to 400 m/s an interval of 30 m/s. The size and temperature distributions of heptane droplets before evaporation, the concentration fields of carbon dioxide, and the temperature fields in the combustion chamber depending on the rate of fuel injection through the injector into the combustion chamber were obtained. The optimal range of heptane injection speed was determined, which is 250 m/s - 280 m/s, in order to increase the efficiency of the combustion chamber and reduce the negative impact on the environment.

Chlorhexidine-Containing Electrospun Polymeric Nanofibers for Dental Applications: An In Vitro Study.

Chlorhexidine is the most commonly used anti-infective drug in dentistry. To treat infected void areas, a drug-loaded material that swells to fill the void and releases the drug slowly is needed. This study investigated the encapsulation and release of chlorhexidine from cellulose acetate nanofibers for use as an antibacterial treatment for dental bacterial infections by oral bacteria Streptococcus mutans and Enterococcus faecalis. This study used a commercial electrospinning machine to finely control the manufacture of thin, flexible, chlorhexidine-loaded cellulose acetate nanofiber mats with very-small-diameter fibers (measured using SEM). Water absorption was measured gravimetrically, drug release was analyzed by absorbance at 254 nm, and antibiotic effects were measured by halo analysis in agar. Slow electrospinning at lower voltage (14 kV), short target distance (14 cm), slow traverse and rotation, and syringe injection speeds with controlled humidity and temperature allowed for the manufacture of strong, thin films with evenly cross-meshed, uniform low-diameter nanofibers (640 nm) that were flexible and absorbed over 600% in water. Chlorhexidine was encapsulated efficiently and released in a controlled manner. All formulations killed both bacteria and may be used to fill infected voids by swelling for intimate contact with surfaces and hold the drug in the swollen matrix for effective bacterial killing in dental settings.

Characterisation and analysis of the surface texture of injection-moulded automotive interior ABS and PP components

Interior automotive plastic components are often manufactured by injection moulding since this technique enables cost-efficient manufacturing, large design freedom, and easy integration of functions. However, to obtain a high-quality impression, it is important to produce components with uniformity in texture, colour, and gloss. Unfortunately, this is rather difficult since a large number of material and processing parameters affect the surface topography and thereby the texture, colour, and gloss. It is therefore important to improve the understanding of how different material and processing parameters affect the surface topography, and in the present study, the influence on surface topography of ABS (Acrylonitrile Butadiene Styrene) and PP (Polypropylene) by melt temperature, tool temperature, and injection speed is investigated by coherence scanning interferometry. Area scale analysis is used to identify the wavelengths of interest, and areal surface parameters are statistically screened to identify robust surface parameters that can be used to discriminate between the surfaces and quantify the influence on surface topography by different material and process variables. Results from the study suggest that tool temperature and injection speed have significant influence on certain surface parameters and, particularly, arithmetic mean height (Sa) and root mean square gradient (Sdq) by approximately 40%, core material volume (Vmc) by 35%, and core roughness depth (Sk) by 50%. These surface parameters are identified as significant and used to discriminate between the sample surfaces.

Thixomolding of Magnesium - Efficient Process Industrialization by Combining a Digital Twin and Systematic Casting Trials

Besides the realization of the technical specification of a casting, aspects such as resource minimization, cost awareness and robustness of the defined quality requirements are taking major priority, especially in the current global economic situation. Lightweight design, in that respect, is a central topic far beyond the automotive industry and characterizes in particular the ongoing research and development of innovative magnesium cast components. As a resource-efficient alternative to traditional die casting, magnesium-thixomolding offers the benefit of low energy consumption and eschews the necessity of protective gases. The identification of significant influencing factors between process settings, shear and time dependent material properties of semi-solid magnesium, the machine capabilities and the resulting casting quality are the basis for effective product and process design of magnesium thixomolding. Obtaining this knowledge is only possible through methodical process analysis and systematic design of experiments. YIZUMI Germany, together with MAGMA, demonstrates the methodical evaluation of a reliable process window for an AZ91D magnesium “box” component, using a demo mold on a UN1250MGII thixomolding machine. The work shows how a systematic combination of virtual and real casting experiments is used to identify a concrete process layout and generate important knowledge on process variations, robustness as well as control limits. In particular, the comparison of virtual and real casting experiments using statistical methods generates a comprehensive understanding of the impact and limits of different process variables, such as fraction solid, mold temperature and injection speeds. Furthermore it is possible to predict the influence of the gating and component design on the process. The methodological use of qualified casting simulation enables the development of an optimized component design and the determination of a suitable process window with minimized economic or productive risks long before the first component is manufactured – a step towards more resource efficiency and sustainability!