期刊文献+
共找到9篇文章
< 1 >
每页显示 20 50 100
Fatigue Performance of Heat Treated TC21 Ti-Alloy 预览
1
作者 Ramadan N. Elshaer Khaled M. Ibrahim +1 位作者 Azza F. Barakat Reham R. Abbas 《金属学报(美国)》 2019年第2期11-18,共8页
TC21 is considered a new titanium alloy that is used in aircraft applications as a replacement for the famous Ti-6Al-4V alloy due to its high strength. The effect of single and duplex stage heat treatments on fatigue ... TC21 is considered a new titanium alloy that is used in aircraft applications as a replacement for the famous Ti-6Al-4V alloy due to its high strength. The effect of single and duplex stage heat treatments on fatigue behavior of TC21 Ti-alloy (Ti-6Al-2Sn-2Zr-3Mo-1Cr-2Nb-0.09Si, wt.%) was investigated. Two heat treatment cycles were applied on as-received TC21 Ti-alloy. The first cycle was called single stage heat treatment (SSHT). The other cycle was named duplex stage heat treatment (DSHT). Typical microstructures of SSHT & DSHT composed of primary 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 treatment. Morphology of α phase does not change after solution treatments, while their volume fraction and grain size were changed. SSHT showed the highest fatigue strength of 868 MPa due to high tensile strength, hardness and existing of high percentages of residual β phase in the microstructure. However, DSHT reported lower fatigue strength of 743 MPa due to increasing grain size of α phase. The fracture surface of fatigue samples showed cleavage ductile fracture mode for both heat treatment cycles. 展开更多
关键词 TC21 Ti-Alloy Solution Treatment Microstructure HARDNESS TENSILE Fatigue
在线阅读 免费下载
Determination of Phase Transformation for TC21 Ti-Alloy by Dilatometry Method 预览
2
作者 Ramadan N. Elshaer Khaled M. Ibrahim +2 位作者 Azza F. Barakat Ahmed I. Farahat Reham R. Abbas 《金属学报(美国)》 2019年第1期1-10,共10页
The α + β ? β phase transformation kinetics of TC21 Ti-alloy during continuous heating and cooling were studied using a dilatometric technique. Dilatometric heating curve exhibited that two characteristic reflectio... The α + β ? β phase transformation kinetics of TC21 Ti-alloy during continuous heating and cooling were studied using a dilatometric technique. Dilatometric heating curve exhibited that two characteristic reflection points can be observed with increasing the heating temperature. Ts referred to the initial transformation temperature of α + β → β and Tf referred to the final transformation temperature of α + β → β. Ts was reported at 720°C, whereas the corresponding Tf was obtained at 950°C. The initial and final transforming temperatures by the first derivative curve were reported at 730°C and 955°C, respectively, which are close to the values obtained in the dilatometric heating curve. Dilatometric cooling curve showed that the starting temperature of β → β + α phase transformation was 880°C;however, the corresponding finishing temperature was 670°C. The starting and finishing temperatures using the first derivative curve were obtained at 665°C and 885°C, respectively. The first derivative for the studied dilatometric heating and cooling curves showed that the starting and finishing temperatures of α + β ? β phase transformation were more accurate and objective. Results show the α + β → β transformation heating curve exhibits a typical S-shaped pattern. 展开更多
关键词 TC21 Ti-Alloy Phase Transformation Dilatometry Heating COOLING
在线阅读 免费下载
Effect of Heat Treatment Processes on Microstructure and Mechanical Behavior of TC21 Titanium Alloy 预览
3
作者 Ramadan N. Elshaer Khaled M. Ibrahim +1 位作者 Azza F. Barakat Reham R. Abbas 《金属学报(美国)》 2017年第3期39-57,共19页
The effect of heat treatment on microstructure and tensile properties as well as wear behavior on TC21 (Ti-6Al-2Sn-2Zr-3Mo-1Cr-2Nb-Si, wt.%) Ti-alloy was investigated. The samples were solution treated at 900°C f... The effect of heat treatment on microstructure and tensile properties as well as wear behavior on TC21 (Ti-6Al-2Sn-2Zr-3Mo-1Cr-2Nb-Si, wt.%) Ti-alloy was investigated. The samples were solution treated at 900°C for 15 min followed by furnace cooling to 800°C with a cooling rate 1°C/min and holding for 20 min, then the samples cooled down to room temperature either using water quenching (WQ) or air cooling (AC). Consequently, aging treatment was applied at 575°C for 4 hr. The microstructure 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 treatment. The highest wear rate was obtained for WQ samples due to increasing in volume fraction of αp (58%). However, the lowest wear rate was reported for WQ + Aging samples due to the high hardness. Optimum mechanical properties of the studied TC21 Ti-alloy were obtained for AC + Aging condition. A better combination of hardness, tensile properties, and wear resistance was achieved for AC + Aging samples, although their wear resistance was found to be slightly lower than that of WQ + Aging samples. 展开更多
关键词 TC21 Ti-Alloy COOLING Rate Aging MICROSTRUCTURE TENSILE Properties WEAR
在线阅读 免费下载
Effect of Notch Severity on Fatigue Behaviour of ADI Castings 预览
4
作者 Khaled M. Ibrahim Bakkar El-Sarnagawy Ibrahim I. Saleh 《材料科学与应用期刊(英文)》 2013年第2期109-117,共9页
An investigation was carried out to examine the influence of notch sensitivity on fatigue behaviour of austempered ductile iron (ADI). Samples were made of ductile iron with a chemical composition of 3.55% C, 2.18% Si... An investigation was carried out to examine the influence of notch sensitivity on fatigue behaviour of austempered ductile iron (ADI). Samples were made of ductile iron with a chemical composition of 3.55% C, 2.18% Si, 0.35% Mn, 0.022 P, 0.008 S and 0.045% Mg. The samples 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 aims at studying the capability of mechanical stress analysis software (ANSYS 12.0), as a nondestructive tool, to characterize and quantify the fatigue strength of the notched ADI samples with different radii (from 1 to 3 mm). In addition, experimental testing was performed using rotary bending fatigue machine on notched samples with radii of 1, 1.5 and 2-mm to verify the theoretical data obtained by ANSYS-12. The results show that the predicted fatigue strength estimated by ANSYS-12 is very close to the experimental one. Therefore, fatigue performance of the rotating parts made of ADI can be estimated theoreticcally using ANSYS 12.0. The fatigue strength of these parts can also be improved by increasing the formed filled radius due to decreasing the notch sensitivity factor. 展开更多
关键词 ADI ANSYS-12 FATIGUE NOTCH Sensitivity
在线阅读 免费下载
铸态和热处理态Ti-6.55Al-3.41Mo-1.77Zr合金微观组织和力学性能 预览
5
作者 Khaled M.IBRAHIM Abdel Moty M.EL-HAKEEM Ramadan N.ELSHAER 《中国有色金属学报:英文版》 SCIE EI CAS CSCD 2013年第12期3517-3524,共8页
采用真空感应熔炼炉将成分为Ti-6.55Al-3.41Mo-1.77Zr(质量分数)的α+β钛合金在石墨模具中浇铸成棒材。铸态棒材在700°C下热锻后,通过两种不同的热处理后,分别得到细小和粗大的层片状结构。结果表明:铸态组织的晶粒尺寸约为... 采用真空感应熔炼炉将成分为Ti-6.55Al-3.41Mo-1.77Zr(质量分数)的α+β钛合金在石墨模具中浇铸成棒材。铸态棒材在700°C下热锻后,通过两种不同的热处理后,分别得到细小和粗大的层片状结构。结果表明:铸态组织的晶粒尺寸约为660μm,而锻造后样品具有细小的晶粒尺寸,约为50μm。在1050°C热处理后的α+β钛合金具有细小的层片状结构,得到最佳的硬度、拉伸性能和耐磨性。在800°C热处理后的α+β钛合金具有粗大的层片状结构,具有最大的抗压强度。具有细小层片状结构的热处理态α+β钛合金的磨损率较小,而铸态α+β钛合金由于具有粗大和不均匀的微观组织,因此磨损率较大。 展开更多
关键词 α+β钛合金 铸态 固溶处理 微观组织 力学性能
在线阅读 下载PDF
低成本β钛合金热处理后的显微组织变化和力学性能 预览 被引量:2
6
作者 KhaledM.IBRAHIM MansourMHAEDE LotharWAGNER 《中国有色金属学报:英文版》 SCIE EI CAS CSCD 2012年第11期2609-2615,共7页
研究了时效时间对低成本β(LCB) Ti-6.6Mo-4.5Fe-1.5Al钛合金的显微组织和力学性能的影响,以及显微组织与疲劳断裂裂纹的产生、延伸的联系。延长时效时间有助于二次α相和β晶粒体积分数的增多以及初始 α相的部分球化。在500 °... 研究了时效时间对低成本β(LCB) Ti-6.6Mo-4.5Fe-1.5Al钛合金的显微组织和力学性能的影响,以及显微组织与疲劳断裂裂纹的产生、延伸的联系。延长时效时间有助于二次α相和β晶粒体积分数的增多以及初始 α相的部分球化。在500 °C下热处理0.5 h的合金得到的拉伸强度最大(1565 MPa),疲劳极限最高(750 MPa);而在500 °C下热处理4 h的合金得到的拉伸强度最小(1515 MPa),疲劳极限最低(625 MPa)。在500 °C下热处理4 h的合金的断裂模式为穿晶断裂, 而在500 °C下热处理0.5 h的合金的断裂模式为穿晶断裂和沿晶断裂的混合。 在疲劳样品的外表面形成的裂纹沿β晶界上初始 α相延伸。 展开更多
关键词 Β钛合金 Ti-6 6Mo-4 5Fe-1 5AL合金 疲劳断裂 时效 二次α相 初始 Α相 β晶粒 拉伸强度 疲劳极限
在线阅读 下载PDF
精密铸造工业纯Ti的力学性能 预览
7
作者 Khaled M. IBRAHIM Mansour MHAEDE Lothar WAGNER 《中国有色金属学报:英文版》 SCIE EI CAS CSCD 2011年第8期 1735-1740,共6页
研究了热旋锻和退火处理对精密铸造工业纯钛显微组织和力学性能的影响。铸造样品为典型的含有不同形貌的α相组织;而旋锻样品是缠绞的层状组织。在500°C退火处理不会显著改变样品的显微组织,但在700°C和870°C退火会导致... 研究了热旋锻和退火处理对精密铸造工业纯钛显微组织和力学性能的影响。铸造样品为典型的含有不同形貌的α相组织;而旋锻样品是缠绞的层状组织。在500°C退火处理不会显著改变样品的显微组织,但在700°C和870°C退火会导致再结晶发生和生成等轴晶组织。铸造棒在近表层生成典型的硬化α层,其最大深度达720μm,最大硬度达HV0.5660。旋锻能使铸造样品的拉伸强度从605MPa增加到895MPa。在500°C退火会导致拉伸强度轻微降低,从895MPa降到865MPa。然而在700°C退火会导致拉伸强度显著下降,从865MPa降到710MPa。当退火温度升高到870°C时,拉伸强度的下降不再明显。铸造和热旋锻样品的断裂应变在0.05~0.12的范围内,而退火后的样品在0.25~0.53的范围。铸态和旋锻态样品表现为脆性解理断裂,而退火态样品为穿晶塑性断裂,伴有韧窝的生成。 展开更多
关键词 工业纯钛 精密铸造 旋锻 热力加工 力学性能
在线阅读 下载PDF
添加晶粒细化剂硅对Ti-6Al-4V合金组织和性能的影响 预览 被引量:1
8
作者 Khaled M.IBRAHIM Abdel Hamied HUSSEIN Mohamed ABDELKAWY 《中国有色金属学报:英文版》 SCIE EI CAS CSCD 2013年第7期1863-1874,共12页
采用真空感应凝壳熔炼工艺在石墨模中制备Ti-6Al-4V和Ti6Al4V0.5Si两种钛合金。将硅作为一种晶粒细化剂加入到Ti-6Al-4V合金中,考察添加硅对铸态和模锻态Ti-6Al-4V合金组织和性能的影响。铸态合金先在900°C下进行热模锻处理,然后... 采用真空感应凝壳熔炼工艺在石墨模中制备Ti-6Al-4V和Ti6Al4V0.5Si两种钛合金。将硅作为一种晶粒细化剂加入到Ti-6Al-4V合金中,考察添加硅对铸态和模锻态Ti-6Al-4V合金组织和性能的影响。铸态合金先在900°C下进行热模锻处理,然后分别进行两种不同的热处理。一种是将模锻样品在1050°C下保温30min,然后水淬以获得细小的层片状组织;另一种是将模锻件在1050°C下保温30min,然后再在800°C下保温30min,以获得粗大的层片状组织。Ti6-Al-4V合金中添加0.5%Si后,铸态合金的晶粒尺寸从627μm减小到337μm,其极限抗拉强度增加约25MPa。具有细小、层片状组织的Ti-6Al-4V0.5Si合金的最大极限抗拉强度为1380MPa,在Hank溶液和NaCl溶液中的腐蚀速度分别为1.35×106和5.78×104mm/a。Ti-6Al-4V合金中添加0.5%Si后,在低滑动速度下的磨损率降低50%,在高滑动速度下的磨损率降低约73%。 展开更多
关键词 TI-6AL-4V合金 铸造 晶粒细化 热处理 磨损添加晶粒细化剂硅对Ti6Al4V合金组织和性能的影响
在线阅读 下载PDF
提高15%Cr-2%Mo过共晶白口铸铁耐磨性能研究 预览
9
作者 R. Reda A. Nofal +1 位作者 Khaled Ibrahim A. Hussien 《铸造》 CAS CSCD 北大核心 2010年第12期 1244-1250,共7页
本研究的主要目的是优化15%Cr-2%Mo过共晶白口铸铁的冲击韧性和耐磨性。研究了动态凝固、铌元素添加和二者共同作用及热处理的影响。采用图像分析仪,扫描电子显微镜(SEM),能量色散光谱仪(EDS)和X射线衍射仪等仪器,对冲击韧性和耐磨... 本研究的主要目的是优化15%Cr-2%Mo过共晶白口铸铁的冲击韧性和耐磨性。研究了动态凝固、铌元素添加和二者共同作用及热处理的影响。采用图像分析仪,扫描电子显微镜(SEM),能量色散光谱仪(EDS)和X射线衍射仪等仪器,对冲击韧性和耐磨损性能进行了测试,还对断口和磨损表面进行了研究。结果表明,对于过共晶(白口)铸铁,凝固过程中的微观组织控制是取得冲击韧性和耐磨性之间的最佳组合的最重要手段。在提高冲击韧性和耐磨性上,添加铌和动态凝固综合作用比每个单一因素更有效。在铸态条件下,动态凝固的冲击韧性和耐磨性比静态凝固分别提高71.4%和10%。加入2%铌后,分别进一步提高到114.3%和28.8%。较低的回火温度260℃比亚临界回火温度500℃显示出更好的耐冲击性和耐磨性。 展开更多
关键词 过共晶铬钼白口铸铁 动态凝固 综合作用 热处理 冲击韧性 断口学 耐磨性 磨损表面
在线阅读 下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部 意见反馈