Bending Strength and Fracture Behaviour of Metal-Ceramic Interpenetrating Phase Composites Manufactured by Using Semi-Solid Forming Technology

2022 ◽  
Vol 327 ◽  
pp. 111-116
Author(s):  
Laura Schomer ◽  
Kim Rouven Riedmüller ◽  
Mathias Liewald
Keyword(s):  
Bending Strength ◽  
Fracture Behaviour ◽  
Structural Characteristics ◽  
Process Window ◽  
Metallic Material ◽  
Forming Technology ◽  
Metal Ceramic ◽  
Semi Solid ◽  
The Impact ◽  
Interpenetrating Phase Composites

Interpenetrating Phase Composites (IPC) belong to a special category of composite materials, offering great potential in terms of material properties due to the continuous volume structure of both composite components. While manufacturing of metal-ceramic IPC via existing casting and infiltration processes leads to structural deficits, semi-solid forming represents a promising technology for producing IPC components without such defects. Thereby, a solid open pore body made of ceramic is infiltrated with a metallic material in the semi-solid state. Good structural characteristics of the microstructure as the integrity of the open-pore bodies after infiltration and an almost none residual porosity within the composites have already been proven for this manufacturing route within a certain process window. On this basis, the following paper focuses on the mechanical properties such as bending strength of metal-ceramic IPC produced by using semi-solid forming technology. Thereby, the impact of the significant process parameters on these properties is analysed within a suitable process window. Furthermore, a fractographic analysis is carried out by observing and interpreting the fracture behaviour during these tests and the fracture surface thereafter.

Structural Characteristics of Metal-Ceramic Interpenetrating Phase Composites Manufactured by Using Semi-Solid Forming Technology

2019 ◽  
Vol 285 ◽  
pp. 51-56 ◽  
Author(s):  
Laura Schomer ◽  
Mathias Liewald
Keyword(s):  
Composite Materials ◽  
Ceramic Body ◽  
Structural Characteristics ◽  
Interface Reactions ◽  
Forming Technology ◽  
Reinforced Composite ◽  
Mould Filling ◽  
Metal Ceramic ◽  
Semi Solid ◽  
Interpenetrating Phase Composites

Interpenetrating Phase Composites (IPC) belong to a special subcategory of composite materials and reveal enhanced properties compared to the more common particle or fibre reinforced composite materials. However, as the use of conventional manufacturing processes creates structural deficits, these IPC are not able to exploit their complete potential. In this respect, infiltration of open-pore bodies from alumina with an aluminium alloy in the semi-solid state offers great perspectives for manufacturing of IPC. In this context, this paper is focusing on significant structural characteristics of metal-ceramic IPC produced in this way by using a tool with an open die cavity. Thereby, the macroscopic mould filling, possible damage of the ceramic body, the residual porosity, the filling of microporosity of the cell walls and possible interface reactions depending on the thermal parameters of the manufacturing process were investigated in this paper.

Fügen von Aluminium- und Kohlenstofffaserstrukturen*/Joining of aluminium and carbon fibre structures - An innovative joining technology based on semi-solid forming strategies

2017 ◽  
Vol 107 (10) ◽  
pp. 743-747
Author(s):  
M. Prof. Liewald ◽  
L. Marx
Keyword(s):  
Carbon Fibre ◽  
Metal Forming ◽  
Carbon Fabric ◽  
Forming Technology ◽  
Joining Technology ◽  
Aluminium Sheets ◽  
Semi Solid ◽  
The University ◽  
The Impact

Das Institut für Umformtechnik (IFU) an der Universität Stuttgart befasst sich derzeit mit der Entwicklung eines neuartigen Verfahrens zum formschlüssigen Fügen von Aluminium- und Carbonstrukturen. Zwei Aluminiumbleche werden dabei lokal auf ein Temperaturniveau knapp oberhalb ihrer Solidustemperatur erwärmt, sodass ein dazwischenliegendes Carbongewebe durch die dann teilflüssige Aluminiummatrix infiltriert werden kann. Dieser Fachartikel befasst sich mit dem Einfluss wichtiger Prozessparameter.   The Institute for Metal Forming Technology (IFU) of the University of Stuttgart aims at the development of a novel joining method for combining aluminium and carbon fibre structures. Two aluminium sheets with carbon fabric in between are conductively heated by two electrodes up to semi-solid state, so the woven carbon fabric is infiltrated with aluminium. This paper focuses on the impact of different process and sample parameters on the quality of the joint.

Numerical Simulation on Thixocasting Process of Auto Box-Like

2011 ◽  
Vol 341-342 ◽  
pp. 177-182 ◽  
Author(s):  
Van Luu Dao ◽  
Sheng Dun Zhao ◽  
Wen Jie Lin ◽  
Yu Qiu Chen
Keyword(s):  
Main Process ◽  
Forming Process ◽  
Billet Temperature ◽  
Forming Technology ◽  
Initial Billet ◽  
Near Net Shape ◽  
Net Shape Forming ◽  
Ram Speed ◽  
Semi Solid ◽  
The Impact

Semi-solid metal processing (thixoforming) is a potential forming technology, which can realize near-net-shape forming process with good quality in one forming step. In this study, semi-solid casting (thixocasting) was used to form the auto box-like. Based on Power Law Cut-Off (PLCO) model and finite element code Procast software, the thixocasting process was modeled and simulated. The impact of main process parameters such as initial billet temperature, ram speed as well as die temperature on the thixocasting process was studied. The results show that thixocasting process can be used in forming auto box-like.

Production of Aluminium Based Interpenetrating Phase Composites Using Semi-Solid Forming

2016 ◽  
Vol 716 ◽  
pp. 502-509 ◽  
Author(s):  
Christoph Seyboldt ◽  
Mathias Liewald ◽  
Daniel Heydt
Keyword(s):  
Liquid Phase ◽  
Aluminium Alloy ◽  
Ceramic Materials ◽  
Raw Material ◽  
Phase Fraction ◽  
Forming Process ◽  
Ceramic Foams ◽  
Forming Technology ◽  
Semi Solid ◽  
Interpenetrating Phase Composites

The following paper deals with the production of Interpenetrating Phase Composites (IPC) using semi-solid forming technology. Therefore, adequate ceramic foams were selected and infiltrated by processing the aluminium alloy A356 in the semi-solid state. In the studies presented in this paper, the infiltrations of two ceramic materials (Al2O3 and SiC) with three different pore sizes (10, 20 and 30 ppi) were investigated. During the forming process the liquid phase fraction of the aluminium was varied to analyze infiltration effects in relation to the raw material´s liquid phase fraction. Afterwards, microsections of the produced specimens were analyzed in order to characterize their microstructure and the quality of infiltration. The results showed that completely filled composite components with good mechanical properties can be produced by infiltrating ceramic preforms with a semi-solid aluminium alloy.

scholarly journals Effect of temperature, CO2 and O2 on motility and mobility of Anisakidae larvae

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aiyan Guan ◽  
Inge Van Damme ◽  
Frank Devlieghere ◽  
Sarah Gabriël
Keyword(s):  
Enzymatic Digestion ◽  
Infected Fish ◽  
Effect Of Temperature ◽  
Video Recordings ◽  
Different Temperatures ◽  
Semi Solid ◽  
Zoonotic Parasites ◽  
The Impact ◽  
Phosphate Buffered Saline

AbstractAnisakidae, marine nematodes, are underrecognized fish-borne zoonotic parasites. Studies on factors that could trigger parasites to actively migrate out of the fish are very limited. The objective of this study was to assess the impact of different environmental conditions (temperature, CO2 and O2) on larval motility (in situ movement) and mobility (migration) in vitro. Larvae were collected by candling or enzymatic digestion from infected fish, identified morphologically and confirmed molecularly. Individual larvae were transferred to a semi-solid Phosphate Buffered Saline agar, and subjected to different temperatures (6 ℃, 12 ℃, 22 ℃, 37 ℃) at air conditions. Moreover, different combinations of CO2 and O2 with N2 as filler were tested, at both 6 °C and 12 °C. Video recordings of larvae were translated into scores for larval motility and mobility. Results showed that temperature had significant influence on larval movements, with the highest motility and mobility observed at 22 ℃ for Anisakis spp. larvae and 37 ℃ for Pseudoterranova spp. larvae. During the first 10 min, the median migration of Anisakis spp. larvae was 10 cm at 22 ℃, and the median migration of Pseudoterranova spp. larvae was 3 cm at 37 ℃. Larval mobility was not significantly different under the different CO2 or O2 conditions at 6 °C and 12 ℃. It was concluded that temperature significantly facilitated larval movement with the optimum temperature being different for Anisakis spp. and Pseudoterranova spp., while CO2 and O2 did not on the short term. This should be further validated in parasite-infected/spiked fish fillets.

scholarly journals Aberrant Bcl-x splicing in cancer: from molecular mechanism to therapeutic modulation

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Zhihui Dou ◽  
Dapeng Zhao ◽  
Xiaohua Chen ◽  
Caipeng Xu ◽  
Xiaodong Jin ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Human Cancer ◽  
Structural Characteristics ◽  
Therapy Resistance ◽  
Regulatory Elements ◽  
Aberrant Splicing ◽  
Clinical Role ◽  
Splicing Isoforms ◽  
The Impact ◽  
Splicing Patterns

AbstractBcl-x pre-mRNA splicing serves as a typical example to study the impact of alternative splicing in the modulation of cell death. Dysregulation of Bcl-x apoptotic isoforms caused by precarious equilibrium splicing is implicated in genesis and development of multiple human diseases, especially cancers. Exploring the mechanism of Bcl-x splicing and regulation has provided insight into the development of drugs that could contribute to sensitivity of cancer cells to death. On this basis, we review the multiple splicing patterns and structural characteristics of Bcl-x. Additionally, we outline the cis-regulatory elements, trans-acting factors as well as epigenetic modifications involved in the splicing regulation of Bcl-x. Furthermore, this review highlights aberrant splicing of Bcl-x involved in apoptosis evade, autophagy, metastasis, and therapy resistance of various cancer cells. Last, emphasis is given to the clinical role of targeting Bcl-x splicing correction in human cancer based on the splice-switching oligonucleotides, small molecular modulators and BH3 mimetics. Thus, it is highlighting significance of aberrant splicing isoforms of Bcl-x as targets for cancer therapy.

scholarly journals Being a Gambler during the COVID-19 Pandemic: A Study with Italian Patients and the Effects of Reduced Exposition

2021 ◽  
Vol 18 (2) ◽  
pp. 424
Author(s):  
Maria Anna Donati ◽  
Silvia Cabrini ◽  
Daniela Capitanucci ◽  
Caterina Primi ◽  
Roberta Smaniotto ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Gambling Behavior ◽  
Online Gambling ◽  
Problem Gamblers ◽  
Electronic Gambling Machines ◽  
Electronic Gambling ◽  
Gambling Market ◽  
The Impact ◽  
Gambling Activities

The COVID-19 pandemic, with the consequent lockdown of about 3 months, can be viewed as an experimental model to observe the impact of the depletion of environmental factors that stimulate gambling, particularly electronic gambling machines (EGMs) that were set to zero. The effects of some structural characteristics of gambling activities that increase gambling behavior were studied among disordered gamblers in treatment in this unique scenario. In fact, studies investigating the effects of the lockdown on problem gamblers (PGs) under treatment are missing. The aims of this study were to analyze patients’ gambling behavior and craving during the lockdown and to conduct a comparison between gambling disorder (GD) symptoms at the beginning of the treatment and during lockdown. The study was conducted in Italy, the European country with the largest gambling market and the first to be affected by the virus. Data were collected through a semi-structured telephone interview conducted by healthcare professionals. Participants were 135 PGs under treatment (109 males, mean age = 50.07). Results showed that most PGs achieved a significant improvement in their quality of life, with less gambling behavior, GD symptoms, and lower craving. No shift toward online gambling and very limited shift towards other potential addictive and excessive behaviors occurred. The longer the treatment, the more monitoring is present and the better the results in terms of symptoms reduction. Individual and environmental characteristics during the lockdown favored the reduction in symptoms. Consideration for prevention and treatment are discussed.

Effect of Spark Plasma Sintering on the Microstructure Evolution and Properties of M3:2 High-Speed Steel

2014 ◽  
Vol 788 ◽  
pp. 329-333
Author(s):  
Rui Zhou ◽  
Xiao Gang Diao ◽  
Jun Chen ◽  
Xiao Nan Du ◽  
Guo Ding Yuan ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Spark Plasma Sintering ◽  
High Speed ◽  
Bending Strength ◽  
Sintering Temperature ◽  
High Speed Steel ◽  
Continuous Heating ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
The Impact

Effects of sintering temperatures on the microstructure and mechanical performance of SPS M3:2 high speed steel prepared by spark plasma sintering was studied. High speed steel sintering curve of continuous heating from ambient temperature to 1200°C was estimated to analyze the sintering processes and sintering temperature range. The sintering temperature within this range was divided into groups to investigate hardness, relative density and microstructure of M3:2 high-speed steel. Strip and quadrate carbides were observed inside the equiaxed grains. SPS sintering temperature at 900°C can lead to nearly full densification with grain size smaller than 20μm. The hardness and bending strength are higher than that of the conventionally powder metallurgy fabricated ones sintered at 1270°C. However, fracture toughness of the high speed steel is lower than that of the conventional powder metallurgy steels. This can be attributed to the shape and distribution of M6C carbides which reduce the impact toughness of high speed steels.

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