[Material properties and tensile strength prediction model of traditional Chinese medicine tablets based on PCA-RBF neural network].

This paper constructs a prediction model of material attribute-tensile strength based on principal component analysis-radial basis neural network( PCA-RBF),in order to predict the formability of traditional Chinese medicine tablets. Firstly,design Expert8. 0 software was used to design the dosage of different types of extracts,the mixture of traditional Chinese medicine with different physical properties was obtained,the powder properties of each extract and the tensile strength of tablets were determined,the correlation of the original input layer data was eliminated by PCA,the new variables unrelated to each other were trained as the input data of RBF neural network,and the tensile strength of the tablets was predicted. The experimental results showed that the PCA-RBF model had a good predictive effect on the tensile strength of the tablet,the minimum relative error was 0. 25%,the maximum relative error was2. 21%,and the average error was 1. 35%,which had a high fitting degree and better network prediction accuracy. This study initially constructed a prediction model of material properties-tensile strength of Chinese herbal tablets based on PCA-RBF,which provided a reference for the establishment of effective quality control methods for traditional Chinese medicine preparations.

Significantly improve film formability of acetylated xylans by structure optimization and solvent screening.

Acetylated xylans have great potential in fabricating functional film and coating materials, which need a good solubility/dispersibility and film formability in an easily evaporable solvent. However, the changes of film formability with degree of substitution by acetyls (DSAc) in different solvent systems for xylans have not been extensively studied, which limit the application of acetylated xylans in film materials. In this study, acetylated xylans with DSAc of 0-2 were prepared and the effects of acetyl groups on solubility/dispersibility, crystallinity and film formability of xylans in water and chloroform solvent systems were investigated. Due to the change of polarity, xylans with DSAc of 0-0.62 are only soluble in water solvents, while xylans with DSAc of 1.13-2 are only soluble in chloroform/ethanol (70/30 v/v) organic solvents. We have found that the film formability of acetylated xylans is highly related to their solubility and crystallization. Film formable xylans all had good solubility in the cast solvents. However, although with good solubility, xylans with DSAc of 0-0.3 and DSAc of 1.76-2 cannot form intact films, which is due to the forming of xylan hydrate crystals and xylan diacetate crystals. With the increase of DSAc, the mechanical property of xylan film increases initially at low DSAc and decreases at high DSAc. This study provides theoretical basis for applying xylans and their derivatives in advanced functional film and coating materials with great biocompatibility and biodegradability.

Microstructure and molten pool morphology of TiB2/ AlSi7Mg composites fabricated by infrared-blue hybrid laser powder bed fusion.

A hybrid laser composed of infrared and blue laser is applied in fabricating TiB2/AlSi7Mg composites on AlSi7Mg substrate by LPBF. The effect on formability, molten pool morphology, molten pool size and microstructure under infrared, blue and hybrid laser were compared. It was confirmed that hybrid laser can make up for the unbalanced energy distribution of infrared laser and the low energy density of blue laser. The increased energy input improves the molten pool size and cellular dendrites size. Therefore, the hybrid laser can improve the formability and forming stability in the LPBF process of low absorption rate alloys.

The Comparison of the Multi-Layer Artificial Neural Network Training Methods in Terms of the Predictive Quality of the Coefficient of Friction of 1.0338 (DC04) Steel Sheet.

Friction is one of the main phenomena accompanying sheet metal forming methods, affecting the surface quality of products and the formability of the sheet metal. The most basic and cheapest way to reduce friction is to use lubricants, which should ensure the highest lubrication efficiency and at the same time be environmentally friendly. Due to the trend towards sustainable production, vegetable oils have been used in research as an alternative to petroleum-based lubricants. The analysis of friction in sheet metal forming requires an appropriate tribotester simulating the friction conditions in a specific area of the sheet metal being formed. Research has used a special strip drawing tribometer, enabling the determination the value of the coefficient of friction in the blankholder zone in the deep drawing process. Quantitative analysis of the friction phenomenon is necessary at the stage of designing the technological process and selecting technological parameters, including blankholder pressure. This article presents the results of friction testing of 1.0338 (DC04) steel sheets using a strip drawing test. The experimental tests involved pulling a strip of sheet metal between two countersamples with a rounded surface. The tests were carried out on countersamples with different levels of roughness for the range of contact pressures occurring in the blankholder zone in the deep drawing process (1.7-5 MPa). The values of the coefficient of friction determined under dry friction conditions were compared with the results for edible (corn, sunflower and rapeseed) and non-edible (Moringa, Karanja) vegetable lubricants. The tested oils are the most commonly used vegetable-based biolubricants in metal forming operations. Multi-layer artificial neural networks were used to determine the relationship between the value of the contact pressure, the roughness of the countersamples, the oil viscosity and density, and the value of the coefficient of friction. Rapeseed oil provided the best lubrication efficiency during friction testing for all of the tested samples, with an average surface roughness of Sa 0.44-1.34 µm. At the same time, as the roughness of the countersamples increased, a decrease in lubrication efficiency was observed. The lowest root mean squared error value was observed for the MLP-4-8-1 network trained with the quasi-Newton algorithm. Most of the analysed networks with different architectures trained using the various algorithms showed that the kinematic viscosity of the oil was the most important aspect in assessing the friction of the sheets tested. The influence of kinematic viscosity on the value of the coefficient of friction is strongly dependent on the surface roughness of the countersamples.

Effect of Chemical Composition on the Thermoplastic Formability and Nanoindentation of Ti-Based Bulk Metallic Glasses.

A series of Ti41Zr25Be34-xNix (x = 4, 6, 8, 10 at.%) and Ti41Zr25Be34-xCux (x = 4, 6, 8 at.%) bulk metallic glasses were investigated to examine the influence of Ni and Cu content on the viscosity, thermoplastic formability, and nanoindentation of Ti-based bulk metallic glasses. The results demonstrate that Ti41Zr25Be30Ni4 and Ti41Zr25Be26Cu8 amorphous alloys have superior thermoplastic formability among the Ti41Zr25Be34-xNix and Ti41Zr25Be34-xCux amorphous alloys due to their low viscosity in the supercooled liquid region and wider supercooled liquid region. The hardness and modulus exhibit obvious variations with increasing Ni and Cu content in Ti-based bulk metallic glasses, which can be attributed to alterations in atomic density. Optimal amounts of Ni and Cu in Ti-based bulk metallic glasses enhance thermoplastic formability and mechanical properties. The influence of Ni and Cu content on the hardness of Ti-based bulk metallic glasses is discussed from the perspective of the mean atomic distance.

Assessing Formability and Failure of UHMWPE Sheets through SPIF: A Case Study in Medical Applications.

This work presents a comprehensive investigation of an experimental study conducted on ultra-high molecular weight polyethylene (UHMWPE) sheets using single point incremental forming (SPIF). The analysis is performed within a previously established research framework to evaluate formability and failure characteristics, including necking and fracture, in both conventional Nakajima tests and incremental sheet forming specimens. The experimental design of the SPIF tests incorporates process parameters such as spindle speed and step down to assess their impact on the formability of the material and the corresponding failure modes. The results indicate that a higher step down value has a positive effect on formability in the SPIF context. The study has identified the tool trajectory in SPIF as the primary influencing factor in the twisting failure mode. Implementing a bidirectional tool trajectory effectively reduced instances of twisting. Additionally, this work explores a medical case study that examines the manufacturing of a polyethylene liner device for a total hip replacement. This investigation critically analyses the manufacturing of plastic liner using SPIF, focusing on its formability and the elastic recovery exhibited by the material.

Study on Press Formability and Properties of UV-Curable Polyurethane Acrylate Coatings with Different Reactive Diluents.

UV-curable coatings have numerous advantages, including environmental sustainability due to 100% solid content, economic feasibility attributable to relatively fast curing time, decent appearance, mechanical properties, chemical resistance, and abrasion resistance. However, UV-curable polyurethane acrylate coatings on metals apparently restrict their engineering applications owing to low mechanical properties and poor thermal stability, giving UV-curable coatings less flexibility and formability. In this study, we evaluated the property change of films according to the type of reactive diluents that lowers the viscosity of UV-curing coatings for pre-coated metal and has a substantial effect on the curing rate, viscoelastic properties, adhesive properties, and flexibility of the film. Moreover, there are many changes in the properties of coatings according to varied curing conditions in order to evaluate the oxygen inhibition phenomenon during the curing process in the atmosphere. In particular, to evaluate the effect of reactive diluents on forming formability, which is the most crucial property for the pre-coated metal, this study used conventional formability tests, such as t-bending or the Erichsen test. Moreover, a cross-die cup drawing mold with a similar form as failure and Safety Zone was utilized in order to obtain clearer information on its actual formability. The analysis on the effect of failure and safety zone on the material used in press forming was conducted by assessing limit punch height and forming a limit diagram of the manufactured film according to varied reactive diluents.

Effect of Rolling Parameters on Room-Temperature Stretch Formability of Mg-2Zn-0.5Ca Alloy.

In this work, Mg−2Zn−0.5Ca (wt.%) alloy sheets fabricated according to various rolling parameters were evaluated to investigate the effect of rolling parameters on room-temperature stretch formability. The sheet rolled at 360 °C with a pass rolling reduction of 10~33% exhibited the worst I.E. value of 4.4 mm, while the sheet rolled at 360 °C with a pass rolling reduction of 20~50% exhibited the best index Erichsen (I.E.) value of 5.9 mm. Among the sheets, the (0002) basal texture intensity was the weakest, and the grain basal poles split away from the normal direction toward both the rolling direction and the transverse direction. Microstructural and deformation mechanism measurements of stretch forming to 2 mm for the sheet rolled at 360 °C with a pass rolling reduction of 20~50% by electron backscatter diffraction and in-grain misorientation axes showed that there was a higher activity of {10−12} extension twins and that a prismatic slip was initiated. As a result, the weakening of the texture and the broader distribution of basal poles in the plane contributed to the improved formability of the sheet rolled at 360 °C with a pass rolling reduction of 20~50%.

The Effect of Nozzle Temperature on the Low-Temperature Printing Performance of Low-Viscosity Food Ink.

Low-temperature food printing technology is used in many fields, such as personalized nutrition, cooking art, food design and medical nutrition. By precisely controlling the deposition temperature of the ink, a food with a finer and more controllable structure can be produced. This paper investigates the influence of nozzle temperature on printing performance via a numerical simulation and experimental research. The results indicate that the ink gradually changed from a granular state to a fLow-characteristic deposition structure when the nozzle temperature increased from 19 °C to 27 °C. When the nozzle temperature exceeded 21 °C, the ink demonstrated excellent extrusion behavior and tended to flow. The widths of the rectangular frame deposition showed no obvious changes and were 4.07 mm, 4.05 mm and 4.20 mm, respectively. The extrusion behavior of the ink showed a structural mutation in the temperature range of 19-21 °C. Its line width changed from 3.15 mm to 3.73 mm, and its deposition structure changed from a grainy shape to a normal shape. Under the influence of different environmental control capabilities, bulk structure deposition demonstrates an ideal printing performance at 21, 23 and 25 °C, and the latter temperature is more suitable in the case of large external interference. The ink flowed violently when the nozzle temperature reached 27 °C, at which point the deposit structure flowed and deformed seriously. On the other hand, evaporation losses had a strong effect on Low-viscosity ink. To reach the full potential of this promising technology, it is necessary to determine the effect of nozzle temperature on printing performance. This article provides a method for developing and applying Low-viscosity, Low-temperature food printing.

A review of manufacturing processes, mechanical properties and precipitations for aluminum lithium alloys used in aeronautic applications.

Military applications and the aeronautic industry are increasingly interested in aluminum lithium alloys (Al-Li) because of the properties required due to the presence of Lithium, which provides a very considerable gain concerning the mechanical properties compared to conventional aluminum alloys. The research and development departments are interested in improving these alloys especially in additive manufacturing process, which leads today to focus on the 3rd generation of Al-Li in terms of part quality - low density compared to the 1st and the 2nd generation. The objectives of this paper is to present a review of Al-Li alloys applications, its carachetrization, the precipitations and their impact on mechanical properties and grain refinement. The various manufacturing processes, methods and tests used are then deeply investigated and presented. The last investigations that have been gotten by scientists over the previous few years on Al-Li for different processes are also reviewed in this research.

On the Competition between Intergranular and Transgranular Failure within 7xxx Al Alloys with Tailored Microstructures.

7xxx aluminium series reach exceptional strength compared to other industrial aluminium alloys. However, 7xxx aluminium series usually exhibit Precipitate-Free Zones (PFZs) along grain boundaries, which favour intergranular fracture and low ductility. In this study, the competition between intergranular and transgranular fracture is experimentally investigated in the 7075 Al alloy. This is of critical importance since it directly affects the formability and crashworthiness of thin Al sheets. Using Friction Stir Processing (FSP), microstructures with similar hardening precipitates and PFZs, but with very different grain structures and intermetallic (IM) particle size distribution, were generated and studied. Experimental results showed that the effect of microstructure on the failure mode was significantly different for tensile ductility compared to bending formability. While the tensile ductility was significantly improved for the microstructure with equiaxed grains and smaller IM particles (compared to elongated grains and larger particles), the opposite trend was observed in terms of formability.

A Review of Characterization and Modelling Approaches for Sheet Metal Forming of Lightweight Metallic Materials.

Lightweight sheet metals are attractive for aerospace and automotive applications due to their exceptional properties, such as low density and high strength. Sheet metal forming (SMF) is a key technology to manufacturing lightweight thin-walled complex-shaped components. With the development of SMF, numerical simulation and theoretical modelling are promoted to enhance the performance of new SMF technologies. Thus, it is extraordinarily valuable to present a comprehensive review of historical development in SMF followed by state-of-the-art advanced characterization and modelling approaches for lightweight metallic materials. First, the importance of lightweight materials and their relationship with SMF followed by the historical development of SMF are reviewed. Then, the progress of advanced finite element technologies for simulating metal forming with lightweight alloys is covered. The constitutive modelling of lightweight alloys with an explanation of state-of-the-art advanced characterization to identify the constitutive parameters are presented. Then, the formability of sheet metals with major influencing factors, the techniques for measuring surface strains in SMF and the experimental and modelling approaches for determining the formability limits are clarified. Finally, the review is concluded by affording discussion of the present and future trends which may be used in SMF for lightweight metallic materials.

Effect of Hot Metal Gas Forming Process on Formability and Microstructure of 6063 Aluminum Alloy Double Wave Tube.

The hot metal gas forming process can significantly improve the formability of a tube and is suitable for the manufacturing of parts with complex shapes. In this paper, a double wave tube component is studied. The effects of different temperatures (400 °C, 425 °C, 450 °C and 475 °C) and different pressures (1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa and 3 MPa) on the formability of 6063 aluminum alloy tubes were studied. The influence of hot metal gas forming process parameters on the microstructure was analyzed. The optimal hot metal gas forming process parameters of 6063 aluminum alloy tubes were explored. The results show that the expansion rate increases with the increase in pressure. The pressure affects the deformation of the tube, which in turn has an effect on the dynamic softening of the material. The expansion rate of parts also increases with the increase in forming temperature. The increased deformation temperature is beneficial to the dynamic recrystallization of 6063, resulting in softening of the material and enhanced deformation uniformity between grains, so that the formability of the material is improved. The optimum hot metal gas forming process parameters of 6063 aluminum alloy tubes are the temperature of 475 °C and the pressure of 2.5 MPa; the maximum expansion ratio is 41.6%.

Effect of Recycling on the Mechanical Properties of 6000 Series Aluminum-Alloy Sheet.

Sustainability is one of the biggest values of today and for the future of our society; a responsible usage of material in every sector is fundamental to achieving sustainability goals. Aluminum alloys are some of the most promising materials in terms of strength and weight, but their production implies the emission of a high amount of CO2. For that reason, the study and development of aluminum alloys with increasing scrap content play a central role in future applications. In the current study, two sheet-aluminum 6181 alloys with different scrap content were analyzed and compared with a 6181 alloy coming from primary production. The alloys were compared in terms of chemical composition, microstructure, tensile properties, and forming behaviors. The results showed that the alloys coming from secondary productions contained a higher amount of manganese, iron, and copper. The metallurgical and mechanical behaviors were very similar to those of the primary produced alloy. Nevertheless, a drop in formability was shown in the aluminum alloys containing a high scrap amount when stressed in a biaxial condition. The study demonstrated the viability of 6181 alloy production using a high scrap amount, highlighting the main difference with the same alloy coming from primary route production.

Effect of Copper Addition on the Formability of 304L Austenitic Stainless Steel.

To improve the antibacterial properties of 304L austenitic stainless steel, copper is often added as an antibacterial agent, but the forming performance of the resulting material is poor, impacting its actual production and use. Therefore, this study investigated the influence of copper addition on the formability of 304L austenitic stainless steel with drawing, cupping and conical cup forming tests. Mechanical properties were determined with tensile and hardness tests. The microstructure and phase transformation were further characterized by metallographic microscopy, scanning electron microscopy and x-ray diffraction analysis. It was found that the addition of copper impaired the mechanical properties of 304L austenitic stainless steel, increased the stacking fault energy of the material and inhibited the occurrence of strain-induced martensite transformation, leading to a decrease in the formability of 304L austenitic stainless steel.

Evaluation of Powder Metallurgy Workpiece Prepared by Equal Channel Angular Rolling.

The aim of the article is to examine the workability of sintered powder material of aluminum alloy (Alumix 321) through severe plastic deformations under the conditions of the equal channel angular rolling (ECAR) process. Accordingly, the stress-strain analysis of the ECAR was carried out through a computer simulation using the finite element method (FEM) by Deform 3D software. Additionally, the formability of the ALUMIX 321 was investigated using the diametrical compression (DC) test, which was measured and analyzed by digital image correlation and finite element simulation. The relationship between failure mode and stress state in the ECAR process and the DC test was quantified using stress triaxiality and Lode angle parameter. It is concluded that the sintered powder material during the ECAR processing failure by a shearing fracture because in the fracture location the stress conditions were close to the pure shear (η and θ¯ ≈ 0). Moreover, the DC test revealed the potential role as the method of calibration of the fracture locus for stress conditions between the pure shear and the axial symmetry compression.

Development of a Formability Prediction Model for Aluminium Sandwich Panels with Polymer Core.

In the present work, the compatibility relationship on the failure criteria between aluminium and polymer was established, and a mechanics-based model for a three-layered sandwich panel was developed based on the M-K model to predict its Forming Limit Diagram (FLD). A case study for a sandwich panel consisting of face layers from AA5754 aluminium alloy and a core layer from polyvinylidene difluoride (PVDF) was subsequently conducted, suggesting that the loading path of aluminium was linear and independent of the punch radius, while the risk for failure of PVDF increased with a decreasing radius and an increasing strain ratio. Therefore, the developed formability model would be conducive to the safety evaluation on the plastic forming and critical failure of composite sandwich panels.

Experimental and Numerical Investigations on the Damage Induced in the Shearing Process for QP980 Steel.

Ultra-high-strength quenching and partitioning (Q&P) steels have achieved remarkable lightweight effect in automotive manufacture due to the excellent mechanical performances. However, the problem of sheared-edge cracking greatly limits their application. In this work, the damage generated in the shearing process of QP980 steel is experimentally investigated via microstructure characterization and micro-/macromechanical property evaluation. Moreover, the shearing deformation is simulated with six widely used damage models. The experimental results reveal that microvoids, microcracks, and work-hardening behavior are the main damage factors affecting the formability of sheared edges. Microvoids mainly formed at phase interfaces have a small size (≤5 µm), while microvoids generated from inclusions with a small number have a large size (>5 µm). As deformation continuously grows, microvoids distributed around the sheared surface are split into microcracks, which act as crack initiators in the subsequent forming step. Additionally, the highest microhardness in the fracture zone further enhances the susceptibility of edge cracking. Furthermore, the optimum damage model for QP980 steel was determined by developing user-defined subroutine VUSDFLD in Abaqus, which can be used in the prediction of fracture behavior of QP980 steel to reduce the risk of edge cracking.

Deformation Characteristics, Formability and Springback Control of Titanium Alloy Sheet at Room Temperature: A Review.

Titanium alloy sheets present inferior formability and severe springback in conventional forming processes at room temperature which greatly restrict their applications in complex-shaped components. In this paper, deformation characteristics and formability and springback behaviors of titanium alloy sheet at room temperature are systematically reviewed. Firstly, deformation characteristics of titanium alloys at room temperature are discussed, and formability improvement under high-rate forming and other methods are summarized, especially the impacting hydroforming developed by us. Then, the main advances in springback prediction and control are outlined, including the advanced constitutive models as well as the optimization of processing paths and parameters. More importantly, notable springback reduction is observed with high strain rate forming methods. Finally, potential investigation prospects for the precise forming of titanium alloy sheet in the future are suggested.

Individual Contribution of Zn and Ca on Age-Hardenability and Formability of Zn-Based Magnesium Alloy Sheet.

This paper reports on the dilemma of the strength and forming behavior of magnesium alloy sheets due to hot rolling and precipitation aging as an obstacle for property adjustment. The effect of the Zn content on the age-hardenability and formability of Mg-Zn-Al-Ca-Mn sheets was investigated. Sheets of two alloys with 2 or 4 wt.% Zn, respectively, were produced by casting and subsequent hot rolling and their microstructure development, precipitation behavior and formability were examined. With higher Zn content the age-hardenability was increased, but at the same time the formability of the sheet decreased, concurrent to the basal-type texture development during rolling. On the other hand, the sheet containing a lower amount of Zn exhibited a weak rolling texture and rather high formability but low age-hardenability. The addition of a larger amount of Zn improved the age-hardenability through the formation of ß1' and ß2' phases. The basal texture was exhibited due to the consumption of solute Ca due to the formation of the Ca2Mg6Zn3 phase. This study suggests that this contradictory exhibition of the age-hardenability and formability of Ca-containing and Zn-based alloy sheets requires a strategical approach in alloy and process design, which allows tailoring the alloying elements and processing for the respective purpose.