scholarly journals The Evaluation of Mechanical Properties of High-tin Bronzes

2017 ◽  
Vol 17 (1) ◽  
pp. 127-130 ◽  
Author(s):  
M. Nadolski
Keyword(s):  
Mechanical Properties ◽  
Functional Properties ◽  
Grain Structure ◽  
Internal Porosity ◽  
Α Phase ◽  
Simultaneous Decrease ◽  
Tin Content ◽  
The Impact ◽  
Be The Change

Abstract High-tin bronzes are used for church bells and concert bells (carillons). Therefore, beside their decorative value, they should also offer other functional properties, including their permanence and good quality of sound. The latter is highly influenced by the structure of bell material, i.e. mostly by the presence of internal porosity which interferes with vibration of the bell waist and rim, and therefore should be eliminated. The presented investigations concerning the influence of tin content ranging from 20 to 24 wt% on mechanical properties of high-tin bronzes allowed to prove the increase in hardness of these alloys with simultaneous decrease in the tensile and the impact strengths (Rm and KV, respectively) for the increased tin content. Fractures of examined specimens, their porosity and microstructures were also assessed to explain the observed regularities. A reason of the change in the values of mechanical properties was revealed to be the change in the shape of α-phase crystals from dendritic to acicular one, and generation of grain structure related to the increased Sn content in the alloy.

scholarly journals Influence of unevened grains of metal on the mechanical properties of seamless hot – rolled pipes.

2020 ◽  
pp. 31-33
Author(s):  
I. A. Kovaleva ◽  
N. A. Khodosovskaya ◽  
M. V. Oborov
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
Physical And Mechanical Properties ◽  
World Market ◽  
Grain Structure ◽  
Pressure Drops ◽  
Impact Performance ◽  
Hot Rolled ◽  
The Impact

Seamless hot – rolled pipes are a popular metal product on the world market. During operation, pipelines are subjected to cyclic loads associated with temperature fluctuations, vibrations near compressor stations, and pressure drops in the transformed medium. One of the ways to ensure high performance properties is to manage the quality of pipe metal, including that laid in the process of metallurgical production. All the basic physical and mechanical properties of metal materials are structurally sensitive and significantly depend on both the grain size and the degree of uniformity of the grain structure, that is, on the different grain sizes. For metallographic research, samples of pipes with the size of 70,0×12,5 mm of S460NH steel were selected with satisfactory (#1) and unsatisfactory (#2) results of the impact. It was found that the inhomogeneous (multi – grained) microstructure in sample #2 was the reason for obtaining unsatisfactory results of the impact. As a result, it was found that one of the most important characteristics that can guarantee stable and satisfactory results of mechanical characteristics, in particular the impact performance, is a homogeneous grain structure.

The Effect of Yarn Linear Density on Mechanical Properties of Plain Woven Kenaf Reinforced Unsaturated Polyester Composite

2013 ◽  
Vol 465-466 ◽  
pp. 962-966 ◽  
Author(s):  
Mohd Pahmi bin Saiman ◽  
Mohd Saidin Bin Wahab ◽  
Mat Uzir Wahit
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Linear Density ◽  
Unsaturated Polyester ◽  
Composite Panel ◽  
Composite Yarn ◽  
Polyester Composite ◽  
The Impact ◽  
Woven Kenaf

To produce a good quality of dry fabric for reinforced material in a natural-based polymer composite, yarn linear density should be in consideration. A woven kenaf dry fabric with three different linear densities of 276tex, 413.4tex and 759tex were produced. The fabrics with different linear densities were been optimize with the assistance of WiseTex software. The optimized dry fabrics were infused with unsaturated polyester to produce composite panel using vacuum infusion process. The composites properties were tested on the tensile strength, flexural strength and the impact strength. The result shows that the mechanical properties of the composite increased when the yarn linear densities increased.

scholarly journals The Impact of Slicing Softwares on the Mechanical Properties of 3D Printed Parts

2020 ◽  
Vol 9 (2) ◽  
pp. 487-494
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
3D Printer ◽  
Stl File ◽  
3D Printed ◽  
Intersection Curves ◽  
The Impact

“Slicing tool” or “Slicing Software” computes the intersection curves of models and slicing planes. They improve the quality of the model being printed when given in the form of STL file. Upon analyzing a specimen that has been printed using two different slicing tools, there was a drastic variation on account of the mechanical properties of the specimen. The ultimate tensile strength and the surface roughness of the material vary from one tool to another. This paper reports an investigation and analysis of the variation in the ultimate tensile strength and the surface roughness of the specimen, given that the 3D printer and the model being printed is the same, with a variation of usage of slicing software. This analysis includes ReplicatorG, Flashprint as the two different slicing tools that are used for slicing of the model. The variation in the ultimate tensile strength and the surface roughness are measured and represented statistically through graphs. An appropriate decisive conclusion was drawn on the basis of the observations and analysis of the experiment on relevance to the behavior and mechanical properties of the specimen.

The Mechanical Properties of the Pipe Steel after Rolling at the Plate Mill

2020 ◽  
Vol 299 ◽  
pp. 335-339
Author(s):  
Sergei I. Platov ◽  
V.A. Nekit ◽  
M.L. Krasnov
Keyword(s):  
Mechanical Properties ◽  
Pipe Steel ◽  
Relative Elongation ◽  
Test Methods ◽  
Continuous Quality ◽  
Metal Products ◽  
Production Output ◽  
The Impact ◽  
Comprehensive Indicator

A study of the mechanical properties of the finished metal products was carried out. All types of metal products are subjected to continuous quality control, both on the production output at the manufacturer of billets, and on the production entrance at the consumer of metal. Control subject are: strength characteristics (tensile strength σв and yield stress σ02 and the characteristics of plasticity (relative elongation δ and relative necking ψ). The pipe steels have another important controlled characteristic: the impact toughness КСU-60. All the test methods are the destroying ones and are characterized by high complexity. The task of reducing the types of tests, the introduction of a comprehensive indicator of product quality is an urgent technical task. The purpose of this work is to study the regularities of changes in the indicators that determine the quality of the sheet metal from the pipe steel.

Influence of the conditions of casting and heat treatment on the structure and mechanical properties of the AlMg10 alloy

2017 ◽  
Vol 1 (83) ◽  
pp. 26-32
Author(s):  
P. Kordas
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Liquid State ◽  
Precipitation Hardening ◽  
Solidification Rate ◽  
Dendritic Structure ◽  
Grain Structure ◽  
Alloy Castings ◽  
Die Castings ◽  
The Impact

Purpose: Assessment of the possibilities of shaping the structure and improvement of mechanical properties of casting from AlMg10 alloy through a selection of casting technology and precipitation hardening. Design/methodology/approach: the work evaluated the impact of casting and heat treatment technology on the mechanical properties and structure of AlMg10 alloy castings. The tests were performed on 200 mm × 100 mm × 25 mm plate castings produced by gravity casting methods for sand and metal moulds and by a liquid state press moulding technology. Castings made with these technologies solidify in substantially different heat- evaporation conditions and exhibit varying degrees of primary structure fragmentation. Metallographic and strength tests were performed on raw castings and after heat treatment. Findings: The changes in the morphology and size of primary crystals and the dispersion of the reinforcing phase according to the casting solidification rate and the precipitation hardening treatment were analyzed. Solidifying castings in the form of sand show a globular structure, whereas in die and press castings, a typically dendritic structure occurs, with the dendritic crystals in pressed castings being much smaller in size than the die castings. In castings which were not heat-treated, the reinforcing phase of Al3Mg2 occurs in interdendritic spaces, and its dispersion increases with the rate of cooling. After supersaturation and ageing treatments, the phase α has a grain structure in all samples. The largest dispersion of reinforcing molecules is characterized by press castings. In a raw state, the highest mechanical properties are shown by castings made in the form of sand and the method of pressing in a liquid state. Heat treatment of AlMg10 alloy castings significantly influences the increase of mechanical indexes in all castings investigated. The highest features of Rm are approx. 330 MPa and A5 above 10% is obtained in castings made by the press method. Research limitations/implications: Particular attention should be paid to the avoidance of the effects of slag inclusion, shrinkage and magnesium oxidation during casting of AlMg10 alloys. In die castings of a plate type, due to own stresses, a significant decrease in mechanical properties occurs. Practical implications: The most advantageous mechanical properties of AlMg10 alloy castings are obtained by using liquid-state pressing technology. In addition, this technology makes it possible to produce thin-walled castings of high dimensional accuracy, high air- tightness, fine grain structure, lack of surface defects and low roughness. Originality/value: The paper presents the possibility of improving the mechanical properties of AlMg10 castings by applying heat treatment. It has been proven that the casting method has a significant effect on the mechanical properties of the castings.

Influence of the Ageing Temperature on the Selected Mechanical Properties of the Ti6Al7Nb Alloy

2015 ◽  
Vol 641 ◽  
pp. 120-123 ◽  
Author(s):  
Robert Dąbrowski ◽  
Janusz Krawczyk ◽  
Edyta Rożniata
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Volume Fraction ◽  
Heating Temperature ◽  
Ageing Temperature ◽  
Sample Length ◽  
Two Phase ◽  
Β Phase ◽  
Α Phase ◽  
The Impact

The results of investigations of the influence of the ageing temperature on the selected mechanical properties i.e. hardness, fracture toughness (examined by the linear elastic fracture mechanics - KIctest) and impact strength (KV) of two-phase Ti6Al7Nb alloy, are presented in the hereby paper. Investigations were performed in the ageing temperatures range: 450÷650°C of the alloy previously undercooled from the selected heating temperature (in two-phase range) - equal 970°C. The heating temperature was determined on the basis of the dilatometric curve of the alloy heating in the system ΔL = f ((T), where: ΔL – change of the sample length, T – temperature, which was then differentiated in the system: ΔL/ΔT = f (T). The dilatometer L78 R.I.T.A of the LINSEIS Company was used in the tests. Investigations of the alloy microstructure in the ageing temperatures range 450÷650°C were carried out by means of the light microscope Axiovert 200 MAT of the Carl Zeiss Company. It was found that nearly equiaxial grains of the primary α phase occur in the microstructure (of the volume fraction app. 30%) and that the volume fraction of the new lamellar α phase - formed from the supersaturated β phase - increases. With an increase of the alloy ageing temperature, in the mentioned above range, a small increase of its hardness from 305 to 324HV as well as a decrease of stress intensity factor KIcfrom 67.3 to 48.6 MPa x m1/2and impact strength (KV) from 40.2 to 31.3 J. The impact tests results were supplemented by the fractographic documentation. It was found, that the characteristic features of the fractures of impact test samples do not exhibit essential differences in dependence of the ageing temperature and material hardness. The fractographic investigations were performed by means of the scanning electron microscope NovaNanoSEM 450.

Research on Preparation and Properties of New Type Desulfurization Gypsum Block

2014 ◽  
Vol 540 ◽  
pp. 217-220
Author(s):  
Chuan Wei Du ◽  
Ying Lv ◽  
Guo Zhong Li
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Water Resistance ◽  
Experimental Results ◽  
New Type ◽  
Cementing Material ◽  
The Impact

Desulfurization building gypsum was used as the main gelled material and fly ash was used as filler to prepare the new type desulfurization gypsum block. the mechanical properties of the new type desulfurization gypsum block was improved by adding compound excitation agent into the desulphurization gypsum-fly ash cementing material to stimulate its activity. The water resistant performance of the new type desulfurization gypsum block was improved through adding wax-alcohol compound waterproofing agent into it. Experimental results show that when the filling amount of fly ash was 20%(the quality of desulfurization gypsum), the impact on the strength of gypsum was minimal; when the dosage of compound excitation agent was 1.75%, the excitation effect of desulphurization gypsum-fly ash cementing material was best; when the dosage of wax-alcohol compound waterproofing agent was 0.4%, the water resistance of new desulfurization gypsum block was optimal.

Investigation of the Influence of Geometric and Technological Factors on the Stress-Strain State of Metal in the Implementation of the Combined Rolling-Pressing Process

2014 ◽  
Vol 936 ◽  
pp. 1918-1924 ◽  
Author(s):  
Sergey Lezhnev ◽  
Eugeny Panin
Keyword(s):  
Metal Forming ◽  
Strain State ◽  
New Technology ◽  
Grain Structure ◽  
Stress Strain ◽  
Technological Factors ◽  
Stress Strain State ◽  
Fine Grain ◽  
The Impact

In the development of new technology metal forming the main purpose is improvement the quality of the source material. The main aspect of quality improvement is increasing the strength characteristics. Often to increase the strength of deformable metal should be given reduced grain structure, up to subultra and even nanolevel. There are several ways to obtain sub-ultra-fine-grain structure of metals, and one of those ways is a method of severe plastic deformation (SPD), implemented in the whole volume of the deformable metal.In this work computer modeling was performed of the combined process "rolling-pressing" with the use of grooved rolls and equal channel step matrix with varying basic geometric and technological factors which have a significant impact on the process, what was made for the analysis of the impact of various factors on the stress-strain state of the process.

scholarly journals Characterisation of Used PP-Based Car Bumpers and Their Recycling Properties

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
M. P. Luda ◽  
V. Brunella ◽  
D. Guaratto
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Impact Resistance ◽  
Dynamic Mechanical Properties ◽  
Speed Test ◽  
The Matrix ◽  
Internal Mixer ◽  
Mineral Fillers ◽  
The Impact

Three used PP-based car bumpers are characterized by many techniques (fractionation, IR, TGA, DSC, DMTA, and SEM). They show different impact and static and dynamic mechanical properties depending on their composition and morphology. It appears that block copolymer compatibilizers constituted by polyethylene-polypropylene sequences allow a better compatibility between the rubber domains and the PP matrix leading to relatively high impact resistance. Indeed if the ethylene sequences of the copolymer are large enough to crystallize, the decreased mobility of the whole system impairs the impact resistance. In addition, a higher amount of rubber in domains regular in shape and of greater dimension (1–3 μm) promotes a more homogeneous dispersion of external force inside the material, decreasing the risk of fracture. The amount of mineral fillers regulates the elastic modulus (the higher the load, the higher the modulus); however, a fairly good interfacial adhesion is required for satisfactory impact strength. All PP-based bumpers have been mechanically recycled in an internal mixer to redistribute oxidized species and to reestablish phase compatibilization. Recycling improves mechanical properties in slow speed test but fails to increase impact strength particularly in filled bumper, in which the quality of the matrix/filler interphase is hard to improve by simple remixing.

scholarly journals Quality of cassava flour as affected by age at harvest, cropping system and variety

2020 ◽  
Vol 53 (4) ◽  
pp. 187-198
Author(s):  
Abiodun Aderoju Adeola ◽  
Michael Ayodele Idowu ◽  
Rebecca ModupeOluwa Oyatogun ◽  
Abdul-Rasaq Adesola Adebowale ◽  
Wasiu Akinloye Oyebisi Afolabi ◽  
...  
Keyword(s):  
Bulk Density ◽  
Mineral Composition ◽  
Functional Properties ◽  
Chemical Properties ◽  
Cropping System ◽  
Cassava Flour ◽  
Swelling Power ◽  
Physico Chemical ◽  
The Impact

AbstractPre-harvest operations affect the quality of food products. This study evaluated the impact of age at harvest (AH), cropping system (CS) and variety on the chemical and functional properties of high quality cassava flour (HQCF). Two white-fleshed (TMS 30572 and TMS 98/0505) and three yellow-fleshed (TMS 97/JW2, TMS 01/1371 and TMS 01/1368) cassava varieties planted either as sole crop or intercropped with maize were harvested at 12, 15 and 18 months after planting, and processed into HQCF. Chemical composition (proximate, mineral), physico-chemical properties (pH, total titratable acidity and colour) and functional properties (bulk density, water absorption index, dispersibility, swelling power, solubility index and pasting properties) of HQCF were determined. Data obtained were analysed using general linear model (GLM). AH had a significant (P < 0.05) effect on proximate and mineral composition, functional and physico-chemical properties, peak and breakdown viscosities, and peak time of HQCF. CS significantly (P < 0.05) affected the crude fibre, fat, bulk density, swelling power, mineral composition, and physico-chemical properties (except L* and b*) of HQCF. Variety significantly (P < 0.05) affected the proximate (except moisture) and mineral composition, functional properties, and breakdown viscosity of HQCF. The interactive effect of AH, CS and variety was significant (P < 0.05) on fat, dispersibility, mineral composition, and physico-chemical properties. In terms of carbohydrate content, it is desirable to harvest cassava at 12 months after planting, with TMS 98/0505 being the choice variety. Recommendation of the desirable AH, CS and variety will vary according to the desired quality of the end-products. Age at harvest is the most important single factor affecting the proximate composition and functional properties of HQCF.

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