000 03154cam a2200349 a 4500
003 EG-GiCUC
005 20250223031505.0
008 160510s2015 ua dh f m 000 0 eng d
040 _aEG-GiCUC
_beng
_cEG-GiCUC
041 0 _aeng
049 _aDeposite
097 _aM.Sc
099 _aCai01.13.12.M.Sc.2015.Mo.G
100 0 _aMohamed Hafez Abdellraheem Qassem
245 1 0 _aGrain refinement of az31 magnesium alloy by cerium addition and thermomechanical treatments /
_cMohamed Hafez Abdelraheem Qassem ; Supervised Abdelhamid Ahmed Hussein , Salah Saeed Ezz , Alzahraa Mohamed Yahia Elbaradie
246 1 5 _aعن طريق إضافة عنصر السيريوم و المعالجات الحرارية الميكانيكية AZ31تدقيق حبيبات سبيكة الماغنسيوم
260 _aCairo :
_bMohamed Hafez Abdelraheem Qassem ,
_c2015
300 _a93 P. :
_bcharts , facsimiles ;
_c30cm
502 _aThesis (M.Sc.) - Cairo University - Faculty of Engineering - Department of Metallurgical Engineering
520 _aThis thesis focuses on the microstructure evolution during different techniques of grain refinement through melt treatment, conventional and advanced thermomechanical treatment (stir friction processing). Two AZ31 alloys with and without Ce-mishmetal addition were cast under Ar/CO protective atmosphere at 750oC, then homogenized at 460oC for two hours. After that they 2 subjected to conventional thermomechanical treatement (hot forging followed by annealing). Firstly, hot forging operated at 350oC to 30% reduction, then, water quenching. Finally, the forged alloys were annealed at 250oC for 16 minutes. Part of commercial AZ31 was conducted to stir friction process (FSP) as a new thermomechanical treatment technique. Friction stir processing was conducted at rotational speed (885 rpm) and transverse speed (62.5 mm/min). On the other hand, finest structure is observed in AZ31-1%Ce (5æm) as a result of conventional thermomechanical treatment and its microstructure is characterized by incomplete fragmentation of Al Ce precipitates. While, the grain size obtained after friction stir processing is 8æm with few fine 4 precipitates within grains. The results of hardness indicates that the maximum hardness is obtained in both stir friction processed AZ31 (75 HV) and conventionally thermomechanical treated AZ31- 1%Ce (82 HV). At the same time, the maximum yield and ultimate tensile strengths are obtained in both stir friction processed AZ31 (160MPa and 260MPa, respectively) and thermomechanical treated AZ31-1%Ce (179 MPa and 255MPa, respectively). Also, higher elongation is recognized in AZ31 (16%) stir friction processed and AZ31-1%Ce (14%) thermomechanical treated
530 _aIssued also as CD
653 4 _aAZ31
653 4 _aForging
653 4 _aStir friction
700 0 _aAbdelhamid Ahmed Hussein ,
_eSupervisor
700 0 _aAlzahraa Mohamed Yahia Elbaradie ,
_eSupervisor
700 0 _aSalah Saeed Ezz ,
_eSupervisor
856 _uhttp://172.23.153.220/th.pdf
905 _aAml
_eCataloger
905 _aNazla
_eRevisor
942 _2ddc
_cTH
999 _c56368
_d56368