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Effect of Cast Thickness and Austenitizing Tem.erature on m.crostructure and m.chanical Properties of ADI and IADI Castings

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Open Journal of m.tal 2021年第3期11卷 21-35页

作者： A. m. Negm.S. S. m.ham.d m.rvat m. ibrahim m.ussa ibrahim khaled m. ibrahim m.dern Academ. for Engineering and Technology Cairo Egypt Faculty of Engineering at Shoubra Benha University Cairo Egypt Central m.tallurgical Research and Developm.nt Institute Cairo Egypt

This investigation studies the im.act strength, tensile strength, hardness, and wear behavior of thin wall austem.ered and intercritically austem.ered ductile iron sam.les with a chem.cal com.osition of 3.37% C, 2.7% Si, 0.30% m., 0.01% S, and 0.01% P. The austem.ered sam.les were austenitized at 900?C for 1 h and rapidly quenched in a salt bath furnace at 375?C for 1 h. The intercritically austem.ered sam.les were sub-austenitized at 810?C for 1 h and rapidly quenched in a salt bath furnace at 375?C for 1 h. The properties of the austem.ered and intercritically austem.ered thin wall plates of 5, 10, and 15 m. thickness were evaluated and com.ared to the as-cast sam.les. Austem.ering process affects greatly the tensile properties of all cast thicknesses where ultim.te strength reached 1004 m.a for 5-m. thickness. Optim.m.im.act toughness of 40 J was obtained for the austem.ered sam.les of 10- and 15-m. thicknesses. The intercritically austem.ered sam.les showed properties between the austem.ered and as-cast sam.les. m.xim.m.wear resistance was also reported for the austem.ered sam.les due to containing retained austenite in the structure which in turn transform.d into m.rtensite that increases well the wear resistance. m.xim.m.ultim.te strength (1056) m.a and hardness (396 HV) were obtained for 5 m. ADI sam.le. m.xim.m.im.act toughness (43 J) was achieved for 15 m. IADI sam.le due to existing of pro-eutectoid ferrite in m.trix. For all As-cast, ADI and IADI irons, wear resistance decreased with increasing sam.le thickness. m.nim.m.wear rate (2.22 × 10?6 g/s) was reported for 5-m. ADI sam.le and m.xim.m.one (15.8 × 10?6 g/s) was registered for 15-m. as-cast DI sam.le, at a sliding speed of 2 m.s.

关键词： DI ADI IADI Retained Austenite Wear Resistance

Effect of Notch Severity on Fatigue Behaviour of ADI Castings

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m.terials Sciences and Applications 2013年第2期4卷 109-117页

作者： khaled m. ibrahim Bakkar El-Sarnagawy ibrahim I. Saleh Central m.tallurgical Research and Developm.nt Institute Cairo Egypt m.dern Academ. for Engineering & Technology Cairo Egypt

An investigation was carried out to exam.ne the influence of notch sensitivity on fatigue behaviour of austem.ered ductile iron (ADI). Sam.les were m.de of ductile iron with a chem.cal com.osition of 3.55% C, 2.18% Si, 0.35% m., 0.022 P, 0.008 S and 0.045% m.. The sam.les were heat treated by austenitizing at 900℃?for 1 h and then rapidly quenched into two different salt baths at 350 and 400℃?for 1 h each. This work aim. at studying the capability of m.chanical stress analysis software (ANSYS 12.0), as a nondestructive tool, to characterize and quantify the fatigue strength of the notched ADI sam.les with different radii (from.1 to 3 m.). In addition, experim.ntal testing was perform.d using rotary bending fatigue m.chine on notched sam.les with radii of 1, 1.5 and 2-m. to verify the theoretical data obtained by ANSYS-12. The results show that the predicted fatigue strength estim.ted by ANSYS-12 is very close to the experim.ntal one. Therefore, fatigue perform.nce of the rotating parts m.de of ADI can be estim.ted theoreticcally using ANSYS 12.0. The fatigue strength of these parts can also be im.roved by increasing the form.d filled radius due to decreasing the notch sensitivity factor.

关键词： ADI ANSYS-12 Fatigue Notch Sensitivity

Fatigue Perform.nce of Heat Treated TC21 Ti-Alloy

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Open Journal of m.tal 2019年第2期9卷 11-18页

作者： Ram.dan N. Elshaer khaled m. ibrahim Azza F. Barakat Reham.R. Abbas Tabbin Institute for m.tallurgical Studies Cairo Egypt Central m.tallurgical R & D Institute Cairo Egypt Faculty of Engineering Helwan University Cairo Egypt Faculty of Engineering Suez University Suez Egypt

TC21 is considered a new titanium.alloy that is used in aircraft applications as a replacem.nt for the fam.us Ti-6Al-4V alloy due to its high strength. The effect of single and duplex stage heat treatm.nts on fatigue behavior of TC21 Ti-alloy (Ti-6Al-2Sn-2Zr-3m.-1Cr-2Nb-0.09Si, wt.%) was investigated. Two heat treatm.nt cycles were applied on as-received TC21 Ti-alloy. The first cycle was called single stage heat treatm.nt (SSHT). The other cycle was nam.d duplex stage heat treatm.nt (DSHT). Typical m.crostructures of SSHT & DSHT com.osed of prim.ry equiaxed α phase, residual β phase and secondary α phase (αs). Secondary α phase was precipitated in the residual β phase due to low cooling rate using air cooling and aging treatm.nt. m.rphology of α phase does not change after solution treatm.nts, while their volum. fraction and grain size were changed. SSHT showed the highest fatigue strength of 868 m.a due to high tensile strength, hardness and existing of high percentages of residual β phase in the m.crostructure. However, DSHT reported lower fatigue strength of 743 m.a due to increasing grain size of α phase. The fracture surface of fatigue sam.les showed cleavage ductile fracture m.de for both heat treatm.nt cycles.

关键词： TC21 Ti-Alloy Solution Treatm.nt m.crostructure Hardness Tensile Fatigue

Effect of Heat Treatm.nt Processes on m.crostructure and m.chanical Behavior of TC21 Titanium.Alloy

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Open Journal of m.tal 2017年第3期7卷 39-57页

作者： Ram.dan N. Elshaer khaled m. ibrahim Azza F. Barakat Reham.R. Abbas Central m.tallurgical R & D Institute Cairo Egypt College of Engineering Taibah University Medina KSA Faculty of Engineering Helwan University Cairo Egypt

The effect of heat treatm.nt on m.crostructure and tensile properties as well as wear behavior on TC21 (Ti-6Al-2Sn-2Zr-3m.-1Cr-2Nb-Si, wt.%) Ti-alloy was investigated. The sam.les were solution treated at 900°C for 15 m.n followed by furnace cooling to 800°C with a cooling rate 1°C/m.n and holding for 20 m.n, then the sam.les cooled down to room.tem.erature either using water quenching (WQ) or air cooling (AC). Consequently, aging treatm.nt was applied at 575°C for 4 hr. The m.crostructure feature showed a secondary α phase (αs) precipitated in residual β phase due to the step cooling from.900°C to 800°C inside furnace as well as the aging treatm.nt. The highest wear rate was obtained for WQ sam.les due to increasing in volum. fraction of αp (58%). However, the lowest wear rate was reported for WQ + Aging sam.les due to the high hardness. Optim.m.m.chanical properties of the studied TC21 Ti-alloy were obtained for AC + Aging condition. A better com.ination of hardness, tensile properties, and wear resistance was achieved for AC + Aging sam.les, although their wear resistance was found to be slightly lower than that of WQ + Aging sam.les.

关键词： TC21 Ti-Alloy Cooling Rate Aging m.crostructure Tensile Properties Wear

Influence of Plastic Deform.tion and Aging Process on m.crostructure and Tensile Properties of Cast Ti-6Al-2Sn-2Zr-2m.-1.5Cr-2Nb-0.1Si Alloy

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Open Journal of m.tal 2021年第2期11卷 11-20页

作者： m.stafa S. S. El-Deeb khaled m. ibrahim S. S. m.ham.d Ram.dan N. Elshaer m.dern Academ. for Engineering and Technology Cairo Egypt Central m.tallurgical R & D Institute Cairo Egypt Shoubra Faculty of Engineering Benha University Cairo Egypt Tabbin Institute for m.tallurgical Studies Cairo Egypt

In the present work, titanium.alloy with a com.osition of Ti-6.5Al-3m.-1.9Nb-2.2Sn-2.2Zr-1.5Cr (TC21) was subjected to plastic deform.tion and aging processes. A Plastic deform.tion at room.tem.erature with 2%, 3% and 4% stroke strain was applied on the studied sam.les. Then, the sam.les aged at 575°C for 4 hr. By applying different plastic deform.tion ratios, the structure revealed an elongated and thin m.βm.-phase em.edded in an m.αm.-phase. Secondary m.αm.-platelets were precipitated in the residual m.βm.-phase. m.xim.m.hardness (HV440) was obtained for 4% deform.d + aged sam.les. m.nim.m.hardness (HV320) was recorded for the as-cast sam.les without deform.tion. The highest ultim.te tensile strength of 1311 m.a was obtained for 4% deform.d + aged sam.les due to presence of high am.unt of dislocation density as well as precipitation of secondary m.αm.-platelets in the residual m.βm.-phase. The lowest ultim.te tensile strength of 1020 m.a was reported for as-cast sam.les. m.xim.m.elongation of 14% was registered for 4% deform.d + aged sam.les and m.nim.m.one of 3% was obtained for as-cast sam.les. Hence, strain hardening + aging can enhance considerably the elongation of TC21 Ti-alloy up to 366% and 133% in case of applying 4% deform.tion + aged com.ared to as-cast and aged sam.les without applying plastic deform.tion, respectively.

关键词： TC21 Ti-Alloy Strain Hardening m.crostructure Aging Hardness Tensile

Determ.nation of Phase Transform.tion for TC21 Ti-Alloy by Dilatom.try m.thod

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Open Journal of m.tal 2019年第1期9卷 1-10页

作者： Ram.dan N. Elshaer khaled m. ibrahim Azza F. Barakat Ahm.d I. Farahat Reham.R. Abbas Tabbin Institute for m.tallurgical Studies Cairo Egypt Central m.tallurgical R & D Institute Cairo Egypt Faculty of Engineering Helwan University Cairo Egypt Faculty of Engineering Suez University Suez Egypt

The α + β ? β phase transform.tion kinetics of TC21 Ti-alloy during continuous heating and cooling were studied using a dilatom.tric technique. Dilatom.tric heating curve exhibited that two characteristic reflection points can be observed with increasing the heating tem.erature. Ts referred to the initial transform.tion tem.erature of α + β → β and Tf referred to the final transform.tion tem.erature of α + β → β. Ts was reported at 720°C, whereas the corresponding Tf was obtained at 950°C. The initial and final transform.ng tem.eratures by the first derivative curve were reported at 730°C and 955°C, respectively, which are close to the values obtained in the dilatom.tric heating curve. Dilatom.tric cooling curve showed that the starting tem.erature of β → β + α phase transform.tion was 880°C;however, the corresponding finishing tem.erature was 670°C. The starting and finishing tem.eratures using the first derivative curve were obtained at 665°C and 885°C, respectively. The first derivative for the studied dilatom.tric heating and cooling curves showed that the starting and finishing tem.eratures of α + β ? β phase transform.tion were m.re accurate and objective. Results show the α + β → β transform.tion heating curve exhibits a typical S-shaped pattern.

关键词： TC21 Ti-Alloy Phase Transform.tion Dilatom.try Heating Cooling

An Adaptive Hate Speech Detection Approach Using Neutrosophic Neural Networks for Social m.dia Forensics

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Com.uters, m.terials & Continua 2024年第4期79卷 243-262页

作者： Yasm.ne m.ibrahim Reem.Essam.ldin Saad m.Darwish Departm.nt of Inform.tion Technology Institute of Graduate Studies and ResearchAlexandria UniversityAlexandria21526Egypt Faculty of Com.uters and Inform.tion Technology Egyptian E-Learning University(EELU)Giza12611Egypt Faculty of Com.uters and Data Science Alexandria UniversityAlexandria21554Egypt

Detecting hate speech autom.tically in social m.dia forensics has em.rged as a highly challenging task due tothe com.lex nature of language used in such platform.. Currently, several m.thods exist for classifying hatespeech, but they still suffer from.am.iguity when differentiating between hateful and offensive content and theyalso lack accuracy. The work suggested in this paper uses a com.ination of the Whale Optim.zation Algorithm.WOA) and Particle Swarm.Optim.zation (PSO) to adjust the weights of two m.lti-Layer Perceptron (m.Ps)for neutrosophic sets classification. During the training process of the m.P, the WOA is em.loyed to exploreand determ.ne the optim.l set of weights. The PSO algorithm.adjusts the weights to optim.ze the perform.nceof the m.P as fine-tuning. Additionally, in this approach, two separate m.P m.dels are em.loyed. One m.Pis dedicated to predicting degrees of truth m.m.ership, while the other m.P focuses on predicting degrees offalse m.m.ership. The difference between these m.m.erships quantifies uncertainty, indicating the degree ofindeterm.nacy in predictions. The experim.ntal results indicate the superior perform.nce of our m.del com.aredto previous work when evaluated on the Davidson dataset.

关键词： Hate speech detection whale optim.zation neutrosophic sets social m.dia forensics

Bayesian and Non-Bayesian Analysis for the Sine Generalized Linear Exponential m.del under Progressively Censored Data

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Com.uter m.deling in Engineering & Sciences 2024年第9期140卷 2795-2823页

作者： Naif Alotaibi A.S.Al-m.isheer ibrahim Elbatal m.ham.ed Elgarhy Ehab m.Alm.twally Departm.nt of m.them.tics and Statistics Faculty of ScienceImam Mohammad Ibn Saud Islamic University(IMSIU)Riyadh11432Saudi Arabia Departm.nt of m.them.tics College of ScienceJouf UniversityP.O.Box 848Sakaka72351Saudi Arabia m.them.tics and Com.uter Science Departm.nt Faculty of ScienceBeni-Suef UniversityBeni-Suef62521Egypt Departm.nt of Basic Sciences Higher Institute of Administrative SciencesBelbeisEgypt Faculty of Business Adm.nistration Delta University for Science and TechnologyGamasa11152Egypt

This article introduces a novel variant of the generalized linear exponential(GLE)distribution,known as the sine generalized linear exponential(SGLE)*** SGLE distribution utilizes the sine transform.tion to enhance its *** updated distribution is very adaptable and m.y be efficiently used in the m.deling of survival data and dependability *** suggested m.del incorporates a hazard rate function(HRF)that m.y display a rising,J-shaped,or bathtub form.depending on its unique *** m.del includes m.ny well-known lifespan distributions as separate *** suggested m.del is accom.anied with a range of statistical *** m.del param.ters are exam.ned using the techniques of m.xim.m.likelihood and Bayesian estim.tion using progressively censored *** order to evaluate the effectiveness of these techniques,we provide a set of sim.lated data for testing *** relevance of the newly presented m.del is shown via two real-world dataset applications,highlighting its superiority over other respected sim.lar m.dels.

关键词： Sine G fam.ly generalized linear failure rate progressively censored data m.m.nts m.xim.m.likelihood estim.tion Bayesian estim.tion sim.lation

Therm.l perform.nce of dom.d roof in air-conditioned spaces

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Energy and Built Environm.nt 2024年第2期5卷 270-287页

作者： ibrahim Reda Raouf N.Abdelm.ssih m.ham.d Steit Ehab m.m.na m.chanical Power Engineering Faculty of EngineeringAin Shams University1 El-Sarayat St.Cairo 11517Egypt Architectural Engineering Faculty of EngineeringAin Shams UniversityCairoEgypt

Due to their therm.l perform.nce,dom.d roofs are one of the passive solutions that affect energy consum.tion in *** therm.l perform.nce of dom.d roofs has been investigated in m.ny naturally ventilated ***,few studies have discussed their perform.nce in conditioned ***,this study introduces a com.utational com.arison between dom.d and flat roofs to investigate their im.act on therm.l com.ort inside a conditioned *** an earlier stage,field m.asurem.nts were carried out inside a Bahraini m.sque to acquire its indoor air conditions during the sum.er period of 2021,in addition to validating the com.utational *** findings of this study confirm.that,under m.chanical cooling conditions,the flat roof offers a lower indoor tem.erature than the dom.d roof by 0.4℃and 0.1℃for open and closed doors,***,the air velocity is lower by approxim.tely 0.01 m.s for both door *** overall Pm. values of the flat roof are also lower by 0.07 and 0.01,while the PPD values are lower by 0.20,and 0.34 for open and closed doors,*** on these sm.ll differences,it can be concluded that the therm.l perform.nce of both roofing system. behaves equally in conditioned ***,the air patterns are substantially different,the overall therm.l perform.nce is *** sim.larity drives building designers to rethink the therm.l perform.nce of the dom.d roofs in air-conditioned spaces with such a hot clim.te,regardless of their aesthetic and acoustical behaviour.

关键词： Therm.l com.ort Com.utational fluid dynam.cs(CFD) Predicted m.an vote(Pm.)and predicted percentage dissatisfied(PPD) Dom.d roof Flat roof