期刊文献+
共找到7篇文章
< 1 >
每页显示 20 50 100
Semi-solid processing of aluminum and magnesium alloys:Status,opportunity,and challenge in China 被引量:9
1
作者 Gan li Wen-ying QU +8 位作者 Min LUO Le CHENG Chuan GUO Xing-gang li Zhen XU Xiao-gang HU da-quan li Hong-xing LU Qiang ZHU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第11期3255-3280,共26页
Owing to its low cost,short process and low energy consumption,semi-solid processing(SSP)of aluminum(Al)and magnesium(Mg)alloys has been considered as a competitive approach to fabricate complicated components with ex... Owing to its low cost,short process and low energy consumption,semi-solid processing(SSP)of aluminum(Al)and magnesium(Mg)alloys has been considered as a competitive approach to fabricate complicated components with excellent performance.Over the past decade,significant progress has been achieved in deeply understanding the SSP process,the microstructure and performance of the fabricated components in China.This paper starts with a retrospective overview of some common slurry preparation methods,followed by presenting the performance and the underlying mechanisms of SSP fabricated alloys.Then,the mainstream opinions on the microstructure evolution and rheological flow behavior of semi-solid slurry are discussed.Subsequently,the general situation and some recent examples of industrial applications of SSP are presented.Finally,special attention is paid to the unresolved issues and the future directions in SSP of Al and Mg alloys in China. 展开更多
关键词 semi-solid processing aluminum alloys magnesium alloys slurry preparation numerical modeling performance industrial applications
下载PDF
Effect of Ti,Sc and Zr additions on microstructure and mechanical properties of rheo-diecasting Al-6Zn-2Mg-2Cu alloys 被引量:2
2
作者 Sai-heng Hou Jian Feng +2 位作者 Song Chen Fan Zhang da-quan li 《China Foundry》 SCIE CAS CSCD 2023年第2期125-133,共9页
The microstructure and mechanical properties of rheo-diecasting Al-6Zn-2Mg-2Cu alloys microalloyed with Ti,Sc and Sc+Zr were studied by optical microscopy(OM),scanning electron microscopy(SEM),X-ray diffraction(XRD),h... The microstructure and mechanical properties of rheo-diecasting Al-6Zn-2Mg-2Cu alloys microalloyed with Ti,Sc and Sc+Zr were studied by optical microscopy(OM),scanning electron microscopy(SEM),X-ray diffraction(XRD),hardness testing,and tensile testing.The swirled equilibrium enthalpy device(SEED)process was introduced to prepare the semisolid slurry.Results show that the addition of Ti,Sc,and Sc+Zr refines the grain size and improves the uniformity of the semisolid slurry and then suppresses the growth of theα-Al grain during solution heat treatment.The microstructure of the four alloys in as-cast state mainly consists of sphericalα-Al and the Mg(Al,Cu,Zn)_(2)(η)eutectic phase.Moreover,primary Al_(3)Sc,Al_(3)(Sc,Zr)and Al_(3)Zr are also found in the micro-alloying alloys.After solution and aging heat treatment,most of the Mg(Al,Cu,Zn)_(2) phases dissolve into theα-Al matrix,while part of Mg(Al,Cu,Zn)_(2) phases transform to Al_(2)CuMg(S)phases.However,the coarse primary Al_(3)Sc and Al_(3)(Sc,Zr)still remain in the matrix,and promote crack initiation and propagation.With the tensile strength of 553 MPa,yield strength of 463 MPa and elongation of 13.4%at T6 state,trace Ti addition generates more attractive mechanical properties than the other three alloys. 展开更多
关键词 Al-Zn-Mg-Cu alloys RHEO-DIECASTING MICROSTRUCTURE mechanical properties micro-alloying
下载PDF
内镜下胃息肉切除术后复发的列线图模型的建立与验证 被引量:6
3
作者 杨彩玲 李大权 +1 位作者 黄永芳 李琳 《中国内镜杂志》 2022年第8期79-85,共7页
目的构建内镜下胃息肉切除术后复发风险的列线图预警模型,并对模型的预测效能进行验证。方法分析271例内镜下胃息肉切除术患者的临床资料,筛选出胃息肉切除术后复发的独立危险因素,并构建风险列线图预警模型。结果胃镜检查和病理学检测... 目的构建内镜下胃息肉切除术后复发风险的列线图预警模型,并对模型的预测效能进行验证。方法分析271例内镜下胃息肉切除术患者的临床资料,筛选出胃息肉切除术后复发的独立危险因素,并构建风险列线图预警模型。结果胃镜检查和病理学检测发现:胃息肉复发者48例,复发率为17.71%;两组患者年龄、进食速度、幽门螺杆菌感染、精神创伤史、息肉数量、息肉直径和病理类型等临床资料比较,差异有统计学意义(P<0.05);Logistic回归分析结果表明:年龄≥50岁、幽门螺杆菌感染、精神创伤史、多发息肉、息肉直径≥2 cm和腺瘤性息肉是内镜下胃息肉切除术后复发的独立危险因素。基于该6项独立危险因素,建立内镜下胃息肉切除术后复发风险的列线图预警模型,结果显示:预测值与实测值基本一致,C指数为0.796(95%CI:0.758~0.834),受试者操作特征曲线(ROC曲线)下面积(AUC)为0.819(95%CI:0.787~0.842)。结论年龄≥50岁、幽门螺杆菌感染、精神创伤史、多发息肉、息肉直径≥2 cm和腺瘤性息肉是内镜下胃息肉切除术后复发的独立危险因素,基于上述危险因素建立的列线图模型,可准确评估和量化胃息肉复发的风险。 展开更多
关键词 内镜 胃息肉切除术 危险因素 列线图预警模型 预测
下载PDF
Effects of Cu content on microstructure and mechanical properties of rheo-diecasting Al-6Zn-2Mg-xCu alloys 被引量:4
4
作者 Zhi-guang Ding Sai-heng Hou +5 位作者 Song Chen Ze-hua liu da-quan li Jian Feng Fan Zhang li-ming Peng 《China Foundry》 SCIE CAS 2022年第4期321-326,共6页
A systematic study on how Cu content affects the microstructure and mechanical properties of rheo-diecasting Al-6Zn-2Mg-xCu alloys during solution treatment and ageing heat treatment was conducted.The swirled enthalpy... A systematic study on how Cu content affects the microstructure and mechanical properties of rheo-diecasting Al-6Zn-2Mg-xCu alloys during solution treatment and ageing heat treatment was conducted.The swirled enthalpy equilibrium device(SEED)was adopted to prepare the semi-solid slurry of Al-6Zn-2Mg-xCu alloys.The microstructure development and mechanical properties were studied using optical microscopy(OM),scanning electron microscopy(SEM),X-ray diffraction(XRD),differential scanning calorimetry(DSC),as well as hardness and tensile testing.The grain boundary and shape factor were calculated using image processing software(Image-Pro Plus 6.0).Results show that the alloys are composed of typical globular primaryα-Al grains,eutectic phases,and smaller secondaryα-Al grains.After solution and ageing heat treatment,the eutectic phases are dissolved into Al matrix when the Cu content is lower than 1.5wt.%,while some eutectic phases transform into Al_(2)CuMg(S)phases and remain at grain boundaries when Cu content reaches 2wt.%.T6 heat treatment significantly enhances the mechanical properties of rheo-diecasting Al-6Zn-2Mg-xCu alloys.When Cu concentration is 0.5wt.%-1.5wt.%,the ultimate tensile strength,yield strength and elongation of T6 treated alloys rise to around 500 MPa,420 MPa,and 18%,respectively. 展开更多
关键词 Al-Zn-Mg-Cu alloy RHEO-DIECASTING Cu content mechanical properties heat treatment
下载PDF
Application of polarized light microscopy on microstructural characterization of semisolid slurry
5
作者 Xiao-Kang liang Qiang Zhu +1 位作者 Min Luo da-quan li 《Rare Metals》 SCIE EI CAS CSCD 2023年第10期3545-3552,共8页
In this paper,two ways of micro structural characterization,optical microscopy(OM) and polarized light microscopy(PLM),were both employed to describe the micro structure of semisolid slurry prepared by swirling enthal... In this paper,two ways of micro structural characterization,optical microscopy(OM) and polarized light microscopy(PLM),were both employed to describe the micro structure of semisolid slurry prepared by swirling enthalpy equilibration device(SEED).The results show that PLM is more reliable and accurate than OM to describe the special morphology feature of semisolid slurry made by SEED process.Meanwhile,the effects of pouring temperature and mass of molten liquid on the primary α-Al particle size and morphology were also investigated using PLM.The quantitative metallographic results measured from PLM demonstrate that the grain size and morphology and their distribution are significantly affected by both pouring temperature and the mass of molten liquid.The grain size poured with 2.7 kg liquid decreases from 659 to186 μm,and grain morphology transforms from dendrite to globular structure with pouring temperature reducing from690 to 630℃.The decreasing pouring temperature also promotes the distribution of spherical structure on the cross section.Meanwhile,the mass of molten liquid decreasing from 2.7 to 2.3 kg can decrease the grain size by maximum of 44% at high pouring temperature. 展开更多
关键词 SEMISOLID Microstructural characterization Polarized light microscopy Pouring temperature Mass of liquid
原文传递
Forming conditions of blisters during solution heat treatment of Al–Si alloy semi-solid die castings
6
作者 Hong-Xing Lu Qiang Zhu +3 位作者 Stephen P.Midson Wen-Ying Qu Fan Zhang da-quan li 《Rare Metals》 SCIE EI CAS CSCD 2023年第11期3851-3858,共8页
In the present study,numerical simulation method was used to analyze the conditions,resulting in the formation of blisters during solution heat treatment.Blister formation is considered to occur as the height of blist... In the present study,numerical simulation method was used to analyze the conditions,resulting in the formation of blisters during solution heat treatment.Blister formation is considered to occur as the height of blister reaches 5μm.The effects of process parameters on the magnitude of the forming temperatures of blister(Tb)were discussed.Two kinds of Al-Si alloys were used to analyze the effect of mechanical properties of the alloys on blister forming conditions.Simulation results show that decreasing the initial pressure in gas hole,the long-short axial ratio of gas hole and the size of gas hole,as well as increasing the depth of gas hole and the strength of alloy are helpful to increase the critical temperature of forming blister.These conclusions are helpful for casters to understand the conditions controlling blister formation during solution heat treatment and take actions to avoid the blister defects. 展开更多
关键词 BLISTER Forming condition Semi-solid die casting Aluminum alloy
原文传递
Microstructure and mechanical property of MIM 418 superalloy 被引量:3
7
作者 Fu-Bao Yang Yan-Hong Jing +3 位作者 Dan li lin Zhang da-quan li Qiang Zhu 《Rare Metals》 SCIE EI CAS CSCD 2018年第1期35-39,共5页
In this study, the influence of hot isostatic pressing(HIP) process on the 418 alloy produced by metal injection molding(MIM) technique(named as MIM 418)was investigated based on the characteristic analysis of 4... In this study, the influence of hot isostatic pressing(HIP) process on the 418 alloy produced by metal injection molding(MIM) technique(named as MIM 418)was investigated based on the characteristic analysis of 418 alloy powder. And comparison analysis of the microstructure and mechanical property between the MIM 418 and as-cast 418 alloys was performed by scanning electron microscopy(SEM), energy-dispersive spectroscopy(EDS),and X-ray diffraction(XRD). The results show that MIM418 alloy exhibits fine grain(~30 μm) and uniform microstructure. The defects existing in MIM 418 alloy formed during sintering process can be eliminated through HIP treatment, and the relative density increases from97.0 % to 99.5 %. The mechanical property can be improved significantly because of the elimination of defects, and the tensile strength and elongation are1,271 MPa and 16.8 %, respectively, which are increased by 34.5 % and 180 % compared with K418 alloy after solution heat treatment. 展开更多
关键词 K418 superalloy Metal injection molding Hot isostatic pressing Microstructure Mechanical property
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部