The Effect of Nitrogen and Inoculation on the Tensile Properties and Microstructure of Cast Iron with Lamellar Graphite

2010 ◽  
Vol 457 ◽  
pp. 114-119 ◽  
Author(s):  
Fredrik Wilberfors ◽  
Ingvar L. Svensson
Keyword(s):  
Cast Iron ◽  
Plastic Strain ◽  
Tensile Properties ◽  
Cell Size ◽  
Deformation Behaviour ◽  
Strain Curve ◽  
Eutectic Cell ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Lamellar Graphite

The main purpose with this paper is to show the effect of nitrogen and inoculation on the tensile properties and microstructure of cast iron with lamellar graphite. Casting experiments were performed with the main composition: 3.4 % C, 2.0 % Si, 0.7 % Mn, 0.5 % Cu. The nitrogen content was varied between 90-180 ppm and inoculant was added as 0, 0.2 or 0.4 % by weight. The addition of inoculant changed the graphite structure from distribution D/B/A to distribution A, according to ISO 945. The eutectic cell size decreased significantly. The addition of inoculant had no influence on the hardness. The addition of nitrogen shortened the graphite flakes and increased the hardness. The influence on the eutectic cell size was low and there was no significant effect on the graphite distribution. Tensile test samples were analysed by true stress – true plastic strain in terms of the flow relationships proposed by Hollomon, , and Ludwigson, . The stress-strain curves were fitted to polynomial functions of the 6:th to 8:th order before evaluating the constants in order to eliminate noise from the measurements. This approach also enabled the slope of the stress-strain curve to be evaluated at zero stress (Young’s modulus), resulting in plastic strain from stress levels close to zero. The Hollomon flow relationship failed to describe the deformation behaviour for the whole range of the stress-strain curve. The correction terms in the Ludwigson flow relationship resulted in a better fit. The addition of inoculant mainly affected the strength coefficient, . The addition of nitrogen also affected the constant. The main reason for this was that the addition of inoculant influenced the last part of the stress-strain curve while the addition of nitrogen had an effect over the whole range of the curve. The addition of nitrogen and inoculant increased the tensile strength from 288 MPa to 393 MPa and the total elongation at fracture from 0.8 % to 1.6 %.

Modelling of the Strain Hardening Behaviour of Die-Cast Magnesium-Aluminium-Rare Earth Alloy

2020 ◽  
Vol 35 ◽  
pp. 1-8
Author(s):  
Hua Qian Ang
Keyword(s):  
Strain Hardening ◽  
Tensile Deformation ◽  
Deformation Behaviour ◽  
Strain Curve ◽  
Deformation Mode ◽  
Prismatic Slip ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Die Cast ◽  
Cast Magnesium

The tensile deformation behaviour of magnesium alloy AE44 (Mg-4Al-4RE) under strain rates ranging from 10-6 to 10-1 s-1 has been investigated. Present study shows that the deformation mode begins with the activation of elastic (Stage 1), followed by <a> basal slip and twinning (Stage 2), <a> prismatic slip (Stage 3) and finally to <c+a> pyramidal slip (Stage 4). The commencement of these deformation mechanisms results in four distinct stages of strain hardening in the stress-strain curve. In this work, the four stages of deformation behaviour are modelled, and an empirical equation is proposed to predict the entire stress-strain curve. Overall, the model predictions are in good agreement with the experimental data. This study on the decomposition of stress-strain curve into four stages provides insights into the contribution of individual deformation mechanism to the overall deformation behaviour and opens a new way to assess mechanical properties of die-cast magnesium alloys.

Experimental Study on Full Stress-Strain Curve of SFRC in Axial Tension

2012 ◽  
Vol 238 ◽  
pp. 41-45
Author(s):  
Hong Yuan Huo ◽  
Chen Jie Cao ◽  
Li Sun ◽  
Li Sha Song ◽  
Tong Xing
Keyword(s):  
Tensile Properties ◽  
Cement Paste ◽  
Steel Fiber ◽  
Strain Curve ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Axial Tension ◽  
Axial Tensile

The tests were carried out to study the effects of the fraction of steel fiber by volume and the thickness of cement paste wrapping steel fibers on the axial tensile properties of steel fiber reinforced concrete (SFRC). The strength grade of SFRC was CF40 with the fraction of steel fiber by volume varying from 0.5% to 2.0%, and the thickness of cement paste wrapping steel fibers varying from 0.8mm to 1.2mm. The tests were conducted by WAW-600 electric-hydraulic servo-type test machine. The results show that the axial tensile properties such as the axial tensile strength, the fullness of stress-strain curve, the tensile energy and the axial tensile toughness ratio are all improved obviously by the adding of steel fiber in concrete. The reasonable thickness of cement paste wrapping steel fibers is 1.0mm. The formulas for stress-strain relationship of SFRC in axial tension are proposed.

scholarly journals Crimp in Wool: Cortical Segmentation and Tensile Properties of Well-Crimped and Abnormally Crimped Fibres of Merino Wool

1965 ◽  
Vol 18 (3) ◽  
pp. 689 ◽  
Author(s):  
RE Chapman
Keyword(s):  
Mechanical Properties ◽  
Tensile Properties ◽  
Strain Curve ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Deficient Diet ◽  
Outer Root Sheath ◽  
Merino Wool ◽  
Root Sheath ◽  
Breaking Points

Poorly crimped (or doggy) fibres, produced by follicles with hyperplasia of the outer root sheath tissue, have greater proportions of paracortex than adjacent well-crimped fibres. Associated with this increase in paracortex is an increase in strength, as indicated by significant increases in the stresses in wet poorly crimped fibres at the turnover and breaking points on the stress-strain curve. Use of the stronger mechanical properties of doggy fibres as a means of distinguishing such fibres from the poorly crimped fibres in steely wool, produced by sheep on a copper-deficient diet, is proposed.

The Research of Aluminum Alloy Honeycomb Sandwich Panel Mechanical Properties in Out-Plane Compression Test

2012 ◽  
Vol 450-451 ◽  
pp. 252-256
Author(s):  
Jin Ping Hu
Keyword(s):  
Aluminum Alloy ◽  
Sandwich Panel ◽  
Split Hopkinson Pressure Bar ◽  
Deformation Behaviour ◽  
Strain Curve ◽  
Average Stress ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Honeycomb Sandwich ◽  
Aluminum Alloy Honeycomb

This paper first studied aluminum alloy honeycomb sandwich panel in out- plane static compress test.Through analyzing deformation characteristics, the loads-displacement relationship was obtained and are described by the average stress-strain curve. Secondly, using the Split Hopkinson Pressure Bar device of impact test, deformation behaviour，dynamic average stress-strain curve data and so on were got under different loading rates, thus learned impact dynamics characteristics of that.

A modified version of MATLAB application window for predicting the weld bead profile and stress–strain plot of AA5052 CMT weldment using ER4043

SIMULATION ◽  
2021 ◽  
pp. 003754972110315
Author(s):  
B Girinath ◽  
N Siva Shanmugam
Keyword(s):  
Strain Curve ◽  
Weld Bead ◽  
Welding Parameters ◽  
Bead Geometry ◽  
Hybrid Technique ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Weld Bead Geometry ◽  
Inference System ◽  
Engineering Stress

The present study deals with the extended version of our previous research work. In this article, for predicting the entire weld bead geometry and engineering stress–strain curve of the cold metal transfer (CMT) weldment, a MATLAB based application window (second version) is developed with certain modifications. In the first version, for predicting the entire weld bead geometry, apart from weld bead characteristics, x and y coordinates (24 from each) of the extracted points are considered. Finally, in the first version, 53 output values (five for weld bead characteristics and 48 for x and y coordinates) are predicted using both multiple regression analysis (MRA) and adaptive neuro fuzzy inference system (ANFIS) technique to get an idea related to the complete weld bead geometry without performing the actual welding process. The obtained weld bead shapes using both the techniques are compared with the experimentally obtained bead shapes. Based on the results obtained from the first version and the knowledge acquired from literature, the complete shape of weld bead obtained using ANFIS is in good agreement with the experimentally obtained weld bead shape. This motivated us to adopt a hybrid technique known as ANFIS (combined artificial neural network and fuzzy features) alone in this paper for predicting the weld bead shape and engineering stress–strain curve of the welded joint. In the present study, an attempt is made to evaluate the accuracy of the prediction when the number of trials is reduced to half and increasing the number of data points from the macrograph to twice. Complete weld bead geometry and the engineering stress–strain curves were predicted against the input welding parameters (welding current and welding speed), fed by the user in the MATLAB application window. Finally, the entire weld bead geometries were predicted by both the first and the second version are compared and validated with the experimentally obtained weld bead shapes. The similar procedure was followed for predicting the engineering stress–strain curve to compare with experimental outcomes.

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