Mechanical properties of lithium metasilicate after short-term thermal treatments

AbstractThe paper describes synthesis and testing of novel biodegradable polylactide-based polymer membranes with desired mechanical properties, which are capable of sustained and directed release of biomacromolecules with high molecular weight (in particular, streptokinase; m.w. 47 kDa). Streptokinase is a pharmaceutical agent, possessing a pronounced thrombolytic activity. The membranes synthesized had a percentage elongation of 2–11% and tensile strength of 25–85 MPa. They were biodegradable – yet being stored in aqueous media in the absence of biological objects, would be dissolved by no more than 10% in 6 months. The synthesized membranes were capable of controlled release of streptokinase into the intercellular space, with the enzyme retaining more than 90% of its initial activity. The rate of streptokinase release from the membranes varied from 0.01 to 0.04 mg/day per cm2 of membrane surface. The membrane samples tested in the work did not have any short-term toxic effects on the cells growing de novo on the membrane surface. The mitotic index of those cells was approximately 1.5%, and the number of non-viable cells on the surface of the polymer films did not exceed 3–4% of their total amount. The implantation of the synthesized polymers – as both individual films and coatings of nitinol stents – was not accompanied by any postoperative complications. The subsequent histological examination revealed no abnormalities. Two months after the implantation of polymer films, only traces of polylactide were found in the implant-surrounding tissues. The implantation of stents coated with streptokinase-containing polymers resulted in the formation of a mature and thick connective-tissue capsules. Thus, the polylactide membranes synthesized and tested in this work are biodegradable, possess the necessary mechanical properties and are capable of sustained and directed release of streptokinase macromolecules.

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Bulk metallic glasses based on precious metals: Thermal treatments and mechanical properties

Intermetallics ◽

10.1016/j.intermet.2015.04.003 ◽

2015 ◽

Vol 63 ◽

pp. 73-79 ◽

Cited By ~ 9

Author(s):

S. Cardinal ◽

J. Qiao ◽

J.M. Pelletier ◽

H. Kato

Keyword(s):

Mechanical Properties ◽

Metallic Glasses ◽

Bulk Metallic Glasses ◽

Precious Metals ◽

Thermal Treatments

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Application of Tailored Heat Treated Blanks under Quasi Series Conditions

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.344.383 ◽

2007 ◽

Vol 344 ◽

pp. 383-390 ◽

Cited By ~ 3

Author(s):

Marion Merklein ◽

Uwe Vogt

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Local Heat ◽

Strength Distribution ◽

Process Window ◽

Short Term ◽

Forming Process ◽

Heat Treated ◽

Set Up ◽

The Impact

Tailored Heat Treated Blanks (THTB) are blanks that exhibit locally different strength specifically optimized for the succeeding forming process. The strength distribution is set by a local, short-term heat treatment modifying the mechanical properties of the material. Hence, THTB allow enhancing forming limits significantly leading to shorter and more robust manufacture process chains. In order to qualify the use of THTB under quasi series conditions, the interdependencies of the blank’s local heat treatment and the entire process chain of the car body manufacture have to be analyzed. In this respect, the impact of a short-term heat treatment on the mechanical properties of AA6181PX, a commonly used aluminum alloy in today’s car bodies, was studied. Also the influence of a short-term heat treatment on the coil lubricant, usually already applied by the material supplier, was given a closer look. Based on these experiments process restrictions for the application of THTB in an industrial automotive environment were derived and a process window for the THTB design was set up. In conclusion, strategies were defined how to enhance the found process boundaries leading to a more robust process window.

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Evaluation of Repair Welding Influence on GH3535 Superalloy Microstructure and Mechanical Properties

Volume 6B: Materials and Fabrication ◽

10.1115/pvp2016-63250 ◽

2016 ◽

Author(s):

Chaowen Li ◽

Shuangjian Chen ◽

Kun Yu ◽

Zhijun Li

Keyword(s):

Mechanical Properties ◽

Arc Welding ◽

Weld Seam ◽

Filler Metal ◽

Short Term ◽

Weld Repair ◽

Repair Welding ◽

Gas Tungsten Arc ◽

Rolled Plates ◽

Carbide Precipitate

GH3535 supperalloy, whose grade of ASME is UNS N10003, is currently considered as a candidate material for solid-fuel and fluid-fuel molten salt reactor in china. During the development of procedures for welding GH3535 superalloy, consideration should always be given to the possibility that repair welding may be necessary. This paper presents weld repairs of GH3535 alloy rolled plates using gas tungsten arc welding with filler metal. The purpose of this work is to evaluate the low heat input process for weld repair of GH3535 alloy plates about the microstructure features and mechanical properties. The results demonstrated that sound joints without defects could be obtained after weld repairs. Due to repair thermal cycles on the original weld seam, the size of carbide precipitate became large, but repair welding is found to cause no decrease in short-term time-independent strength.

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107 The Role of Tissue Engineering in Auricular Reconstruction: A Critical Review

British Journal of Surgery ◽

10.1093/bjs/znab259.689 ◽

2021 ◽

Vol 108 (Supplement_6) ◽

Author(s):

F Moura ◽

R Varley ◽

C Yao

Keyword(s):

Mechanical Properties ◽

Tissue Engineering ◽

Immune Response ◽

Critical Review ◽

3D Bioprinting ◽

Short Term ◽

Auricular Reconstruction ◽

Cartilage Reconstruction ◽

Promising Solution

Abstract Aim Despite several decades of research in tissue engineering, reconstructing a 3D human-sized ear that can stand the test of time has remained a challenge. Autologous cartilage reconstruction remains the main treatment choice despite the associated morbidity. Progress in the field has been made and several studies have used tissue-engineered implants in immunocompetent animals with promising results. Method This study critically reviews and assesses the characteristics that make auricular reconstruction so challenging and how far research has come in addressing the following: mechanical properties; vascularisation; immune response; cell sourcing; surgical attachments; allografts; and cost. Results The question is whether tissue engineering will realistically replace autologous cartilage reconstruction in the short-term, or will advances in other areas, outlined in this article, manage to provide suitable and aesthetically accurate scaffolds. Conclusions Advances in tissue engineering are slowly progressing and utilise advances in both biomaterial design and 3D bioprinting to try and address the challenges of auricular reconstruction. Tissue engineering is still a promising solution to auricular reconstruction but still requires further research before becoming a reality.

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EFFECT OF THERMO-MECHANICAL TREATMENT ON PROPERTIES OF PARICA PLYWOODS (Schizolobium amazonicum Huber ex Ducke)

Revista Árvore ◽

10.1590/1806-90882017000100015 ◽

2017 ◽

Vol 41 (1) ◽

Cited By ~ 3

Author(s):

Mírian de Almeida Costa ◽

Cláudio Henrique Soares Del Menezzi

Keyword(s):

Mechanical Properties ◽

Mechanical Treatment ◽

Physical And Mechanical Properties ◽

The Other ◽

Modulus Of Rupture ◽

Thermal Treatments ◽

Mechanical Compression ◽

Specific Mass ◽

Thermo Mechanical Treatment ◽

Temperature And Pressure

ABSTRACT Thermo-mechanical treatment is a technique for wood modification in which samples are densified by means of heat and mechanical compression, applied perpendicularly to fibers, which under different combinations of time, temperature, and pressure increases wood density and thus improve some of its properties. This study aimed to treat thermo-mechanically parica plywood and observe the effects on its physical and mechanical properties. Specimens were submitted to two treatments, 120 and 150 ºC, remaining under pressure for seven minutes and, subsequently, under zero pressure for 15 minutes. Results showed a significant increase in specific mass from 0.48 g cm-3 to an average of 0.56 g cm-3, and a compression ratio of about 31.7% on average. Physical properties also varied significantly and results showed that treated samples swelled and absorbed more water than those untreated, leading to a greater thickness non-return rate. This indicates the proposed thermal treatments did not release the internal compressive stress generated during panel pressing, not improving its dimensional stability as a result. On the other hand, mechanical properties were positively affected, leading to an increase of 27.5% and 51.8% in modulus of rupture after treatments at 120 and 150 ºC, respectively. Modulus of elasticity and glue-line shear strength did not vary statistically and Janka hardness was 29.7% higher after treatment at 150 ºC.

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DYNAMIC CRACK TOUGHNESS OF AUSTEMPERING STEEL

Characterization and Application of Nanomaterials ◽

10.24294/can.v0i0.650 ◽

2018 ◽

Author(s):

Tatyana Avdjieva

Keyword(s):

Mechanical Properties ◽

High Strength ◽

Dynamic Crack ◽

Thermal Treatments ◽

Hydroelectric Power ◽

High Rigidity ◽

Power Stations ◽

Microstructure And Mechanical Properties ◽

Oil Pipelines ◽

Complex Engineering

This work is a part of research on the microstructure and mechanical properties of Cr-Ni-Si steels after various thermal treatments [1, 2]. The need to minimize damage and losses caused by emerging failures in complex engineering facilities such as nuclear, thermal and hydroelectric power stations, and gas and oil pipelines necessitates the creation of materials of high strength, plasticity, welding and high rigidity.

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Mechanical Response of Ni-Based CU5MCuC Alloy to Different Stabilization Thermal Treatments

International Journal of Metalcasting ◽

10.1007/s40962-020-00519-x ◽

2020 ◽

Author(s):

Andrea Gruttadauria ◽

Silvia Barella ◽

Claudia Fiocchi

Keyword(s):

Mechanical Properties ◽

Corrosion Resistance ◽

Mechanical Strength ◽

Intergranular Corrosion ◽

Mechanical Response ◽

Annealing Treatment ◽

Mechanical Tests ◽

Thermal Treatments ◽

Stabilization Treatment ◽

Cr System

Abstract The Ni–Fe–Cr system is the basis of a series of commercial alloys featuring chemical–physical characteristics that allow them to be used in a variety of fields where excellent resistance to aggressive environments is required. In this scenario, the CU5MCuC alloy, the foundry counterpart of Alloy 825, is proving successful in the petrochemical field thanks to its good corrosion resistance in acidic and highly oxidizing environments. Intergranular corrosion resistance, critical for this material, is ensured by the stabilization treatment that allows precipitation of Nb carbides. Strengthening of this alloy takes place only via a solid solution. Therefore, its mechanical properties depend on the solution annealing treatment: often this treatment alone does not make it possible to reach the UTS imposed by the ASTM-A494 standard. In this work, the possibility of using stabilization treatment to increase mechanical strength as well was considered. Treatments, with different combinations of time and temperature, were carried out in order to modify the material’s microstructure. After the thermal treatments, microstructural analyses, mechanical tests and (pitting and intergranular) corrosion and resistance tests were carried out to identify optimal treatment parameters in order to promote the evolution of microstructural constituents capable of improving mechanical strength without decreasing corrosion resistance. The treatment that achieves the best compromise between mechanical properties and corrosion resistance is stabilization at 970 °C for 4 h.

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