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The die steel NAK80 is used in specular optical molds, deep drawing forming dies, and cold extrusion dies in large quantities; high strength and hardness often induce tool wear during machining. This study established a tool wear prediction method for measuring, using the cutting temperature and chip chromaticity characteristic values to predict the tool life. The back propagation neural network (BP-LM) was compared with a long-short term memory (LSTM) model in the prediction method, and different characteristic signals were imported into the BP-LM and LSTM methods to predict the tool wear. In Taylor’s curve diagram, the repeatability accuracies of tool wear and cutting temperature are 2.83% and 9.29%, respectively. The BP-LM method was used for prediction in the comparison of prediction methods. When the input characteristic were temperature, chip chromaticity, and temperature and chip chromaticity, the MAPE percentage errors are 24.23%, 31.87%, and 19.88%, respectively. The error was reduced by 29% when the input characteristics were temperature and chip chromaticity. When the LSTM model was used for prediction, and the input characteristics were temperature, chip chromaticity, and temperature and chip chromaticity, the MAPE percentage errors are 30.33%, 28.55%, and 22.1%, respectively. The error was reduced by 25% when the input characteristics were temperature and chip chromaticity. Therefore, using the characteristic temperature and chip chromaticity in the BP-LM and LSTM prediction models resulted in good forecast accuracy, and a new model prediction form for tool life was provided.

The paper deals with the FEM (Finite Element Method) simulation of rotary swaging of Dievar alloy produced by additive manufacturing technology Selective Laser Melting and conventional process. Swaging was performed at a temperature of 900°C. True flow stress-strain curves were determined for 600°C–900°C and used to construct a Hensel-Spittel model for FEM simulation. The process parameters, i.e., stress, temperature, imposed strain, and force, were investigation during the rotary swaging process. Firstly, the stresses induced during rotary swaging and the resistance of the material to deformation were investigated. The amount and distribution of imposed strain in the cross-section can serve as a valuable indicator of the reduction in porosity and the texture evolution of the material. The simulation revealed the force required to swag the Dievar alloy. It also showed the evolution of temperature, which is important for phase transformation during solidification. Furthermore, microstructure evolution was observed before and then after rotary swaging. Dievar alloy is a critical material in the manufacture of dies for high-pressure die casting, forging tools, and other equipment subjected to high temperatures and mechanical loads. Understanding its viscoelastoplastic behavior under rotary swaging conditions is essential to optimize its performance in these demanding industrial applications.

Fluidity tests of pure aluminum 1070 and Al-Si alloys with Si contents of up to 25% were conducted using a die cast machine equipped with a spiral die. The effects of the channel gap, die temperature, and injection speed on the fluidity were investigated. When the channel gap was small (0.5 mm), the flow length of the 1070 was minimized, and the fluidity increased monotonically at a gradual rate with increasing Si content. In contrast, larger gaps yielded convex fluidity–Si content curves. Additionally, heating the die had less of an influence on the fluidity of the 1070 than on that of the Al-Si alloy. These results are discussed in the context of the peeling of the solidification layer from the die based on the thicknesses of foils and strips cast by melt spinning and roll casting, respectively. At lower Si contents, heat shrinkage was greater and the latent heat was lower. When the heat shrinkage was greater, the solidification layer began to peel earlier, and the heat transfer between the solidification layer and the die became smaller. As a result, the fluidity of the 1070 was greatest when the channel gap was 0.8 mm.

This paper uses Pro/E and CAD software to carry out the design of die-casting mold structure for industrial cabinet lock handle.Firstly, the three-dimensional modeling, process analysis and calculation of the handle parts are carried out, and then the solid model is established.The die-casting machine is selected according to the clamping force. Finally, the opening and closing die is simulated, and the general assembly drawing of the die-casting die is drawn to ensure the cooperation with other parts without interference, which is of certain guidance to the actual production.

Forming complex geometries using the casting process is a big challenge for bulk metallic glasses (BMGs), because of a lack of time of the window for shaping under the required high cooling rate. In this work, we open an approach named the “entire process vacuum high pressure die casting” (EPV-HPDC), which delivers the ability to fill die with molten metal in milliseconds, and create solidification under high pressure. Based on this process, various Zr-based BMGs were prepared by using industrial grade raw material. The results indicate that the EPV-HPDC process is feasible to produce a glassy structure for most Zr-based BMGs, with a size of 3 mm × 10 mm and with a high strength. In addition, it has been found that EPV-HPDC process allows complex industrial BMG parts, some of which are hard to be formed by any other metal processes, to be net shaped precisely. The BMG components prepared by the EVP-HPDC process possess the advantages of dimensional accuracy, efficiency, and cost compared with the ones formed by other methods. The EVP-HPDC process paves the way for the large-scale application of BMGs.

H13 tool steel was deposited using the additive manufacturing technique Direct Metal Deposition to produce a part having a wedge geometry. The wedge was characterized both in terms of microstructure and residual stress. It was found that phase transformations were significantly influencing the microstructure, which was then linked to the residual stress distribution as seen in Fig. 8. The residual stress distribution was found to be opposite to that reported in the literature. This was attributed to the low temperature martensitic phase transformation of the H13 tool steel and the subsequent tempering of the microstructure with an increasing number of layers of deposited material. The high hardness and compressive residual stress of the top 4 mm of the wedge are ideal in die casting and forging dies, as it will resist thermal fatigue. It also has a hardness higher than that produced by typical heat treatment processes.

Disciplining the Holocaust examines critics' efforts to defend a rigorous and morally appropriate image of the Holocaust. Rather than limiting herself to polemics about the \"proper\" approach to traumatic history, Karyn Ball explores recent trends in intellectual history that govern a contemporary ethics of scholarship about the Holocaust. She examines the scholarly reception of Goldhagen's Hitler's Willing Executioners, the debates culminating in Eisenman's Memorial to the Murdered Jews of Europe in Berlin, Lyotard's response to negations of testimony about the gas chambers, psychoanalytically informed frameworks for the critical study of traumatic history, and a conference on feminist approaches to the Holocaust and genocide. Ball's book bridges the gap between psychoanalysis and Foucault's understanding of disciplinary power in order to highlight the social implications of traumatic history.

In this work, the failure characteristics of a die-casting die manufactured from conventional hot-worked steel (SKD61) were investigated experimentally. A die with heat-checking failure on its cavity due to high-pressure die casting was employed. Apparently, the microstructural characteristics of the die around the regions exhibiting heat checking were unaltered. However, the hardness values decreased slightly because of the die heating via the injection of molten aluminum alloy, which is the tempering-like effect. Hydrogen was detected in the die around the regions with heat checking, which can slightly reduce the tensile fracture strain, i.e., hydrogen embrittlement (HE). The extent of HE was sensitive to the loading speed, particularly to a low loading speed. When heated to 450 °C, hydrogen gas was detected in a commercial die lubricant, which may lead to hydrogen infiltration in the die. This paper discusses the details pertaining to hydrogen penetration and die failure mechanisms.

Die-casting die steel is widely used in the manufacturing of automobile parts and 5G communication equipment. However, it requires high thermal strength and stability during usage. This study investigated the thermal stability and the thermal fatigue resistance as well as the microstructure and composition of the self-developed new Cr3 die-casting die steel 4Cr3Mo2V by using an optical microscope (OM), scanning electron microscope (SEM), energy dispersion spectrum (EDS), and transmission electron microscope (TEM). The experimental results demonstrate that the M 23 C 6 in the testing steel visibly grows and aggregates as the holding time increases. And the M 23 C 6 -type carbides in the 4Cr3Mo2V and 4Cr5Mo2V steels account for 46 and 52% of the total carbides, respectively, especially when the temperature is maintained at 600 °C for 64 h. The lower percentage M 23 C 6 carbides in 4Cr3Mo2V steel have improved the thermal stability and thermal fatigue resistance of the steel.

The article presents a comprehensive review of key issues and challenges related to enhancing the durability of hot forging tools. It discusses modern strategies aimed at increasing tool life, including modifications to tool materials, heat treatment, surface engineering, tool and die design, die geometry, tribological conditions, and lubrication. The review is based on extensive literature data, including recent publications and the authors’ own research, which has been implemented under industrial conditions at the modern forging facility in Forge Plant “Glinik” (Poland). The study introduces original design and technological solutions, such as an innovative concept for manufacturing forging dies from alloy structural steels with welded impressions, replacing traditional hot-work tool steel dies. It also proposes a zonal hardfacing approach, which involves applying welds with different chemical compositions to specific surface zones of the die impressions, selected according to the dominant wear mechanisms in each zone. General guidelines for selecting hardfacing material compositions are also provided. Additionally, the article presents technological processes for die production and regeneration. The importance and application of computer simulations of forging processes are emphasized, particularly in predicting wear mechanisms and intensity, as well as in optimizing tool and forging geometry.