Maximum Percentage Elongation Research Articles

Machine Learning for Parametrical Analysis of Friction Stir Welded Aluminum Metal Matrix Composites

The research focuses on the behaviour and process parametric influence on friction stir welded Al metal matrix composites reinforced with varied percentages of SiC, B4C, and Mg. The experimentation involves fabrication of Al metal matrix composites followed by friction stir welding and, subsequently, evaluation of the joint properties in terms of mechanical strength, microstructural integrity, and quality. In comparison to other joints with varied base material compositions, the weld exhibits refined grains and uniform distribution of hybrid particles in the joint region, resulting in increased strength. Higher SiC composition adds to greater strength, better wear characteristics, and harness, whereas B4C percentage is linked to hardness. The maximum ultimate tensile stress for a particular sample was determined to be around 160MPa, while the maximum percentage elongation was found to be around 165 for 10% SiC and 3% B4C. As the amount of SiC declines and that of B4C rises, the percentage elongation decreases. In samples with a B4C weight percentage of 10%, the greatest hardness measured was around 103Hv. For a load of 30N, the wear rate was as high as 12gm/s with a SiC weight percentage of 10. For lower load values and a higher percentage of B4C, the wear rate often decreased. Chemical properties are barely changed. Therefore, the materials keep their original qualities after welding. During the non-destructive testing process, no large cracks, pores, or clusters of pores are found, indicating that the weld is of good quality. To achieve a satisfactory weld, optimal ranges based on analysis using machine learning of rotary tool speed, tool linear velocity, transverse speed are maintained. Linear Regression algorithm, Random Forest algorithm and Lasso Regression algorithms are being used and the results are also compared. This work covers a wide range of topics, and the results are found to have improved significantly in most cases and is in good agreement with data previously presented in the literatures.

Physico-chemical/mechanical properties of treated groundnut shell fibre; Response surface methodology and artificial neural network performance evaluation and optimisation

The difficulties associated with forecasting mechanical behaviours of fibres based on the theoretical method is a big threat to precise design when dealing with complex variables; hence, the need to evaluate the fibres' properties using artificial intelligence techniques to minimise error. This study predicted the effect of acetylation process parameters (treatment time and concentration) on the mechanical properties (elongation at break and tensile strength) of groundnut shell fibre (GSF) using Response surface methodology (RSM) and Artificial neural network (ANN). The GSF was processed, dried and treated with NaOH varying the time and concentration of the treatment and then acetylated. The characterisation results from the physicochemical analysis, SEM and FTIR indicated that acetylation treatment removed excess lignin, hemicellulose and cellulose from GSF and improve its bonding characteristics. Assessment of the models through the coefficient of determination (R2) and mean square error (MSE) indicates that ANN for elongation at break (R2 =0.9999, MSE=2.769E-13) and tensile strength (R2 =0.99997, MSE=3.5146E-18) is superior to the RSM model for elongation at break (R2 =0.9264, MSE 1.59) and for tensile strength (R2 =0.9326, MSE=7.71) in predicting mechanical properties of GSF. Numerical optimisation revealed that optimal values of 3 h and treatment concentration of 3% gave a maximum percentage elongation at break of 10.583% and 135.045 MPa for tensile strength. This result shows that acetylation treatment enhanced the physicochemical/mechanical properties of GSF thereby making it suitable for composite processing.

Effects of tool pin profile on the formation of friction stir processing zone in AA1100 aluminium alloy

In the current investigation the effect of tool pin profiles (threaded cylindrical and straight cylindrical) on the mechanical properties (ultimate tensile strength, percentage elongation and joint efficiency) of friction stir welded and friction stir processed aluminium alloy (AA1100) was investigated. Taguchi L-18 array was used to select the transverse and rotational speed of the tool. The three distinct variables (tool shape, speed and feed rate) were used during investigation. From the results it was found that the joint fabricated by threaded tool profile gives maximum tensile strength and percentage elongation than the straight cylindrical tool pin profile. It is also found that, the threaded tool pin have good joint efficiency as compared to cylindrical tool i.e. maximum of 90% at 1800 rpm and feed rate of 50 mm/min. The joint constructed by threaded tool have maximum percentage elongation (8.38%) at 2400 rpm and feed rate of 45 mm/min. In addition, the joints fabricated by threaded tool pin profile have exhibited more ductility than cylindrical tool profile.

Microstructural and mechanical studies of feedstock material in continuous extrusion process

The challenge encountered in continuous forming process is the variation in mechanical strength of product formed with respect to process variables like extrusion wheel speed and diameter of product. In this research article, the micro-structural investigation of the aluminum (AA1100) feedstock material of 9.5-mm diameter has been carried out at various extrusion wheel speeds and diameter of product before and after deformation on commercial continuous extrusion setup TBJ350. The mechanical properties like yield strength as well as percentage elongation have been estimated and optimized using two variables with 3 levels through central composite rotatable design (CCRD) method. The mathematical modeling has been carried out to predict the optimum combination of process parameters for obtaining maximum value of yield strength and percentage elongation. The statistical significance of mathematical model is verified through analysis of variance (ANOVA). The optimum value of yield strength is found to be 70.939 MPa at wheel velocity of 8.63 rpm and product diameter of 9 mm respectively, whereas the maximum percentage elongation recorded is 46.457 at wheel velocity of 7.06 rpm and product diameter of 7.18 mm. The outcome may be useful in obtaining the best parametric combination of wheel speed and extrusion ratio for best strength of the product.

Annealer curve characteristics of electrolytically refined tough pitch copper (Cu-ETP) and oxygen free up-cast copper (Cu-OF) for electrical cable wires

Annealing is a critical step during the wire drawing of copper to produce wires with the required ductility and conductivity for electrical applications. In this investigation, the characteristics of commercial annealers for wire drawing of electrolytically refined tough-pitch copper (Cu-ETP) and oxygen-free upcast copper (Cu-OF) wires were assessed through annealer curves with respect to applied voltage and resulting percentage elongation of final products. Experiments were carried out on three M315 Niehoff machines of varying speeds used for medium wire drawing from 2.2 ​mm diameter to 0.66 ​mm and 0.53 ​mm diameters. The results show similarities and differences between annealer curve characteristics of wire drawing machines regarding the required voltage for minimum and maximum elongation of wires without oxidation depending on the type of copper raw material used. In particular, the minimum 18% required elongation of wires was achieved with the same applied voltage irrespective of the machine speed and type of copper. In addition, Cu-OF reached higher maximum percentage elongation without oxidation of the wire compared to Cu-ETP.

The effect of reinforced SiC on the mechanical properties of the fabricated hypoeutectic Al-Si alloy by centrifugal casting

Centrifugal casting is one of the advanced casting techniques widely used in modern metallurgical industries. The current work is concerned and focuses on study the effects of a selected horizontal and vertical centrifugal casting parameters including, the type of the process, the mold rotation (spinning) speeds and the adding ratio of carbide silicone (SiC) micro powder on the quality of the hypoeutectic AlSi alloy hollow cylindrical fabricated workpieces by using the response surface methodology (RSM) and the full factorial design (FFD) for the design of experiments (DOE). After examined the qualities of the producing workpieces, it is found that the finest porosities were obtained when using the vertical centrifugal casting processes, especially at mold speed of 920 RPM without adding the SiC powder and the porosity sizes increased at higher mold speeds up to 1440 RPM. At these mold speeds the inner surfaces of the produced workpieces seen with lowest raining and shrinkage cavities defects, and with the best outer surfaces qualities especially when using the adding of 0.6% SiC powder. The maximum tensile strength obtained when using the higher mold speed and the corresponding G factor values, without using the added SiC mixed powder and when using the vertical centrifugal casting, reached 167 MPa. The maximum proof stresses were obtained when using the higher mold speed values, the added SiC mixed micro powder and using the vertical centrifugal casting, reached 13.6 MPa. Finally, the maximum percentage elongation was obtained when using the mold speed of 920 RPM, which equivalent to G factor value of 56 with using of the added SiC mixed powder and vertical centrifugal casting reached 1.6%. This means that the values of maximum tensile strength, proof stresses and percentage elongation obtained for the hypoeutectic Al-Si Alloy hollow cylindrical fabricated workpieces when using the centrifugal casting processes, increased by 355, 13.3 and 87,5%, respectively when comparing with the using of the conventional gravitational casting process.

Effect of tungsten content on the structure, physical and mechanical properties of silicon bronze (Cu-3 wt%Si)

This research investigated the effect of tungsten content on the structure, physical and mechanical properties of silicon bronze (Cu-3 wt%Si). Tungsten was added in concentrations of 0.1, 0.3, 0.5, 0.8, 1 and 1.5 wt%. The samples were produced using permanent die casting technique, machined and stored for the structural analysis, physical and mechanical tests. The microstructural analysis of the control sample (Cu-3 wt%Si) revealed the presence of dendrite of intermetallic compounds which could be primary silicon and copper silicide (Cu3Si) phases while the alloy doped with tungsten consisted of fine grains of intermetallic compounds evenly dispersed in the copper matrix. The mechanical tests results showed that addition of tungsten to silicon bronze significantly increased the percentage elongation, ultimate tensile strength, hardness and electrical conductivity of the alloy by 174.5%, 741.2%, 98.9% and 14.9% respectively. Maximum percentage elongation, electrical conductivity, ultimate tensile strength and hardness of 25.8%, 61.25% IACS, 286 MPa and 358 BHN respectively were obtained.

Invivo and invitro tensile properties of orthodontic elastomeric chains – A comparative study

Aim: This study was to evaluate the permanent elongation and tensile strength of elastomeric chains in vivo and in vitro of three commonly available brands. Materials and Method: Two types (open & closed chains) of three brands of elastomeric modules producing six groups were included in the study. Specimens were measured by digital caliper and classified into four groups based on their ageing state: (a) as received; (b) subjected to a 24 hours steady strain in air determined as 50% of original length; (c) exposed intraorally for 24 hours; and (d) retrieved following 3 weeks of intraoral exposure. The final lengths of all the specimens were measured and mean percentage elongation was calculated for each group and was analysed with two-way ANOVA. For tensile strength, the specimens were subjected to the above said conditions and were subjected to tensile stress and their behavior was analysed with three-way ANOVA and Tukey’s multiple comparison test. Results: The results showed that open E-chains show more percentage elongation compared to closed types. The tensile strengths of the E-chains in all the groups decreased after being subjected to intraoral conditions. The decrease in the tensile strength was proportional to the time in the oral cavity. Conclusion: Open E-chains have higher percentage elongation compared to closed E- chains in vitro but closed E-chains have higher percentage elongation compared to open E-chains in vivo. Among the different test conditions, the maximum percentage elongation was seen after 3 weeks intraoral stretching and least by the E-chains stretched 24 hours in air. The tensile strength was most in the in vitro conditions and least after three weeks stretching intraorally. Clinical Significance: The most important problem of the E-chains is their force decay during the time so being aware of the various factors that can affect their characteristic and force decay pattern is essential. This can help practitioners to use chains in a better way. Keywords: Elastomeric chains; Force decay; Mechanical properties; Permanent elongation; Tensile strength

Evaluation of Aluminium Alloy for Plasticity Applications

An evaluation of aluminium alloy for plasticity applications was undertaken to bridge the gap in appraising the impact of variation of alloying elements such as magnesium (Mg) and copper (Cu) on plasticity as a mechanical property of the aluminium alloy. To this end, twenty seven (27) samples of aluminium alloys were produced with constituents drawn from 6 % zinc (Zn), 2.5 % - 3.5 % magnesium (Mg), 1.8 % - 3.0 % copper (Cu), 0.03 % manganese (Mn), 0.23 % chromium (Cr) and aluminium (Al) as balance in all cases. 0.1 gram of sulphur (S), which the same as the quantity of iron (Fe) in chromium (Cr) and manganese (Mn), was added to oxidize (eradicate) iron (Fe). Samples were subjected to hardness test; to measure the ability of the alloy to resist plastic deformation and percentage elongation (% e) to unveil the mechanical properties of the alloy. Maximum Vickers hardness (Hv) of 130.7 was displayed by an alloy of 6 % zinc (Zn), 2.5 % magnesium (Mg), 1.8 % copper (Cu), 0.03 % manganese (Mn), 0.23 % chromium (Cr) and aluminium, quenched in water at 490°C and soaked for five (5) hours. The same alloy, non-heat treated, displayed a least Hv of 91.5. Hardness increased from 91.5 Hv in an alloy of 2.5 percentage weight of magnesium to 120.3 Hv in an alloy of 3.5 percentage weight of magnesium. Maximum percentage elongation (% e) of 130.00 was recorded by an alloy of 3.5 % Mg and 2.5 % Cu. A least percentage elongation of 12.00 % was established in an alloy of 3.5 % Mg and 3.0 % Cu. The experiment observed that with increase in percentage weight of magnesium from 2.5 % - 3.0 % - 3.5 %, there was variation from 25.67-18.67- 130.00 respectively in percentage elongation. The alloy with 3.5 % Mg, 1.8 % Cu was recommended for plasticity (% elongation) applications. Investigation of the impacts of other constituents on this alloy may be considered.

Experimental investigation on flow-forming of AA6061 alloy—A Taguchi approach

Abstract An annealed AA6061 aluminum tubing preform was cold flow-formed into a seamless tube. A multiple pass flow-forming was performed. In this investigation, the influence of the various flow-forming process parameters on the percentage elongation (%D) has been analyzed. The parameters considered are the speed of the mandrel, S (rpm), the depth of cut, Dc (mm) and the feed, F (mm/min). The effects of these input parameters on the response, percentage elongation (%D) have been critically analyzed using Taguchi method. It has been found that the depth of cut is the most important process parameter affecting the percentage elongation. The flow-forming process produced a maximum percentage elongation of 18% when the process parameters were set at their optimum values.

The elastic constants and ultrastructure organization of regenerated basement membrane (lens capsule).

The regenerated basement membrane of the crystalline lens of the rat has been found to have the following elastic constants: a Young's modulus of elasticity of 0.6 +/- 0.48 X 10(6) N m-2 at low stress and 7.8 +/- 2.0 X 10(6) N m-2 at rupture, an ultimate stress of 19.7 +/- 7.0 X 10(5) N m-2, and a maximum percentage elongation of 33.7 +/- 6.1%. Electron microscopic observations of ultrasonicated fragments of the entire membrane show long filaments in parallel arrays and sheets. The filaments show a periodicity of 3.4 nm and a spacing of 3.2 nm. Electron microscopic observations of regenerated membrane treated with collagenase show a poorly staining matrix with separate short thin and thick non-periodic filaments, their diameters being 1.4 nm and 2.5 nm respectively. In addition, strands project from the ends of filaments with a diameter between 0.5 and 1.0 nm. The reduced ultimate strength and Young's modulus of elasticity at rupture in regenerated membrane as compared with normal membrane is considered to be due to the preponderance of thinner filaments in the former. Normal membrane contains not more than 33% of thin filaments whereas regenerated membrane contains at least 78% of such filaments. A comparison of the diameters of thin and thick filaments indicates that thick filaments are probably composed of five strands while thin ones contain three strands.

Thickness and volume constants and ultrastructural organization of basement membrane (lens capsule).

1. The basement membrane of the crystalline lens of the rat has been found to have the following elastic constants: a Young's Modulus of elasticity of 0.56 +/- 0.38 x 10(6) Nm-2 at low stress and 11.3 +/- 1.9 x 10(6) Nm-2 at rupture, an ultimate stress of 28.8 +/- 4.5 x 10(5) Nm-2, and a maximum percentage elongation of 41.3 +/- 5.8. 2. The ratio of initial thickness of the membrane to the thickness at the point of rupture is 0.271 +/- 0.02 while the similar ratio for volume is 0.461 +/- 0.031. 3. Electron microscopic observations of ultrasonicated fragments of the entire membrane show long filaments in parallel arrays and sheets. The filaments show a periodicity of 3.7 nm and a spacing of 3.5 nm. 4. Electron microscopic observations of collagenase-treated membrane show a poorly staining matrix associated with separate short straight non-periodic filaments some 2.5 nm in diameter. In addition strands project from the ends of the filaments with a diameter of between 0.5 and 1.0 nm. 5. A model is proposed which consists of these filaments, composed of between three and five parallel strands, some 0.8 nm in diameter, wound in a superhelix. 6. The model predicts satisfactorily thickness and volume changes in the membrane when subjected to stress, and also indicates that the filaments would have a similar Young's Modulus of elasticity and ultimate stress to those of collagen. 7. If the basement membrane of the smallest retinal capillaries is subjected to a change of pressure of only 5 mmHg within the vessel lumen, then the membrane is likely to undergo some 30% reduction in thickness.

Elastic constants of the human lens capsule.

1. A technique is described whereby the elasticity of the human lens capsule has been determined at birth and throughout life. This technique requires three separate determinations: (a) thickness; (b) stress and strain; (c) Poisson's ratio; (a) the capsule was clamped between accurately perforated ground glass plates and its thickness determined by noting the change in depth of focus between Latex spherules adhering to its upper and lower surfaces; (b) the undisturbed capsule was then placed in a specially designed glass distension apparatus and the relationship between volume and pressure recorded when it was distended with isotonic saline. The permeability of the capsule was also measured; (c) in some cases Poisson's ratio was determined by measuring the change of thickness of the capsule and the height to which it rose when distended with isotonic saline at different pressures. An apparatus was designed for this purpose.2. The average thickness of the anterior capsule increases from birth until about the 60th year but thereafter it decreases slightly.3. Poisson's ratio was about 0.47 for both cat and human capsule, and no significant variations with age in human capsule could be detected.4. Corrected volume pressure curves obeyed Hook's law almost to the point of capsule rupture.5. In childhood Young's Modulus of elasticity is about 6 x 10(7) dyn/cm(2) and decreases to 3 x 10(7) dyn/cm(2) at 60 and 1.5 x 10(7) dyn/cm(2) in extreme old age.6. The ultimate tensile stress was 2.3 x 10(7) dyn/cm(2) in young capsules and 0.7 x 10(7) dyn/cm(2) in old ones. The maximum percentage elongation was 29 per cent and independent of age.7. The implications of these findings are discussed in relation to(a) the mechanical properties of the lens capsule;(b) the ageing of the lens capsule and basement membranes; and(c) the decrease in elasticity of the lens capsule as a cause of presbyopia.