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International Journal of Minerals,Metallurgy and Materials 2018年第9期25卷 1018-1026页

作者： Chong lin shu-sen Wu shu-lin lü Ping An He-bao Wu State Key laboratory of Materials Processing and Die & Mould Technology Huazhong University of Science and Technology Hubei Provincial Key laboratory of Chemical Equipment Intensification and Intrinsic Safety Wuhan Institute of Technology

The effects of high pressure rheo-squeeze casting(HPRC) on the Fe-rich phases(FRPs) and mechanical properties of Al-17 Si-(1,1.5)Fe alloys were investigated. The alloy melts were first treated by ultrasonic vibration(UV) and then formed by high-pressure squeeze casting(HPSC). The FRPs in the as-cast HPSC Al-17 Si-1 Fe alloys only contained a long, needle-shaped β-Al5 Fe Si phase at 0 MPa. In addition to the β-Al5 Fe Si phase, the HPSC Al-17 Si-1.5 Fe alloy also contained the plate-shaped δ-Al4 Fe Si2 phase. A fine, block-shaped δ-Al4 Fe Si2 phase was formed in the Al-17 Si-1 Fe alloy treated by UV. The size of FRPs decreased with increasing pressure. After UV treatment, solidification under pressure led to further refinement of the FRPs. Considering alloy samples of the same composition, the ultimate tensile strength(UTS) of the HPRC samples was higher than that of the HPSC samples, and the UTS increased with increasing pressure. The UTS of the Al-17 Si-1 Fe alloy formed by HPSC exceeded that of the Al-17 Si-1.5 Fe alloy formed in the same manner under the same pressure. Conversely, the UTS of the Al-17 Si-1 Fe alloy formed by HPRC decreased to a value lower than that of the Al-17 Si-1.5 Fe alloy formed in the same manner.

关键词： high pressure rheo-squeeze casting Al-17Si-(1,1.5)Fe alloys Fe-rich phases mechanical properties

Progress in preparation of AlN-reinforced magnesium matrix composites:A review

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China Foundry 2024年第1期21卷 1-10页

作者： lu Chen shu-lin lü Di-jia Zhao Wei Guo Jian-yu li shu-sen Wu State Key lab of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

As a ceramic material,AlN has very good thermophysical and mechanical *** addition,AlN is an effective refining agent for Mg alloys because it has a lattice constant similar to that of ***,AlN is an ideal reinforcement for magnesium matrix composites(MMCs),and is attracting increasing *** review addresses the development of preparation technologies for AlN-reinforced Mg matrix *** mainstream preparation techniques include stir casting,melt infiltration,powder metallurgy,and in-situ *** addition,the advantages and disadvantages of these techniques are analyzed in depth,and it is pointed out that the next direction for the preparation of high-performance AlN-reinforced MMCs is less aluminization and multiple technologies integration.

关键词： AlN MMCs preparation thermophysical property mechanical property

Effects of heat treatment on microstructure evolution and mechanical properties of Mg-6Zn-1.4Y-0.6Zr alloy

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China Foundry 2017年第3期14卷 199-204页

作者： Jing Wang Xiao-gang Fang shu-sen Wu shu-lin lü State Key lab of Materials Processing and Die & Mould Technology Huazhong University of Science and Technology Wuhan 430074 China

To investigate the effects of solution temperature and the decomposition of I-phase on the microstructure, phase composition and mechanical properties of as-cast Mg-6Zn-1.4Y-0.6Zr alloy, solution treatment at 440 oC, 460 oC and 480 oC and further aging treatment were conducted on the alloy. The results indicate that the net-like intermetallic compounds(mainly I-phase) dissolve into the α-Mg matrix gradually with the increase of solution temperature from 440 oC to 480 oC. Besides, the I-phase decomposes completely at 480 oC, with the formation of fine W-phase(thermal stable phase) and Mg_7Zn_3 phase. In addition, a great number of fine and dispersive Mg-Zn binary phases precipitate in the α-Mg matrix during the aging treatment. Due to the increase of solute atoms and the precipitation of strengthening phases, such as W-phase and Mg-Zn phases, the optimal strength is obtained after solution treatment at 460 oC for 8 h and aged at 200 oC for 16 h. The yield strength(YS), ultimate tensile strength(UTS) and elongation are 208 MPa, 257 MPa and 3.8%, respectively. Compared with the as-cast alloy, the increments of YS and UTS are 117% and 58%, respectively, while the decrement of elongation is 46%.

关键词： magnesium alloy heat treatment microstructure mechanical properties

Nano-SiC_P particles distribution and mechanical properties of Al-matrix composites prepared by stir casting and ultrasonic treatment

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China Foundry 2018年第3期15卷 203-209页

作者： shu-sen Wu Du Yuan shu-lin lü Kun Hu Ping An State Key lab of Materials Processing and Die & Mould Technology Huazhong University of Science and Technology

Nano-ceramic particles are generally difficult to add into molten metal because of poor wettability. Nano-SiC particles reinforced A356 aluminum alloy composites were prepared by a new complex process, i.e., a molten-metal process combined with high energy ball milling and ultrasonic vibration methods. The nano particles were β-SiCp with an average diameter of 40 nm, and pre-oxidized at about 850 ℃ to form an oxide layer with a thickness of approximately 3 nm. The mm-sized composite granules containing nano-SiCp were firstly produced by milling the mixture of oxidized nano-SiCp and pure Al powders, and then were remelted in the matrix-metal melt with mechanical stirring and treated by ultrasonic vibration to prepare the composite. SEM analysis results show that the nano-SiC particles are distributed uniformly in the matrix and no serious agglomeration is observed. The tensile strength and elongation of the composite with 2wt.% nano-SiCp in as-cast state are 226 MPa and 5.5％, improved by 20％ and 44％, respectively, compared with the A356 alloy.

关键词： metal matrix composites SiC nanopaticles A356 aluminum alloy solid-liquid mixed casting ultrasonic vibration

Distribution pattern of acoustic and streaming field during multi-source ultrasonic melt treatment process

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China Foundry 2023年第5期20卷 452-460页

作者： Xiao-gang Fang Qi Wei Tian-yang Zhang Ji-guang liu You-wen Yang shu-lin lü shu-sen Wu Yi-qing Chen School of Materials Science and Engineering Hefei University of TechnologyHefei 230009China Engineering Research Center of High-Performance Copper Alloy Materials and Processing Ministry of EducationHefei 230009China State Key laboratory of Material Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan 430074China

The ultrasonic melt treatment(UMT)is widely used in the fields of casting and ***,there are certain drawbacks associated with the conventional process of single-source ultrasonic(SSU)treatment,such as the fast attenuation of energy and limited range of *** this study,the propagation models of SSU and four-source ultrasonic(FSU)in Al melt were respectively established,and the distribution patterns of acoustic and streaming field during the ultrasonic treatment process were investigated by numerical simulation and physical *** simulated results show that the effective cavitation zone is mainly located in a small spherical region surrounding the end of ultrasonic horn during the SSU treatment *** the FSU is applied,the effective cavitation zone is obviously expanded in the *** increases at first and then decreases with increasing the vibration-source spacing(lv)from 30 mm to 100 ***,when the lv is 80 mm,the area of effective cavitation zone reaches the largest,indicating the best effect of ***,the acoustic streaming level and flow pattern in the melt also change with the increase of *** the lv is 80 mm,both the average flow rate and maximum flow rate of the melt reach the highest,and the flow structure is more stable and uniform,with the typical morphological characteristics of angular vortex,thus significantly expanding the range of acoustic *** accuracy of the simulation results was verified by physical experiments of glycerol aqueous solution and tracer particles.

关键词： four-source ultrasound acoustic cavitation streaming field vibration-source spacing

Effects of nano-SiC_p content on microstructure and mechanical properties of SiC_p/A356 composites assisted with ultrasonic treatment

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Transactions of Nonferrous Metals Society of China 2018年第11期28卷 2174-2181页

作者： Kun HU Du YUAN shu-lin lü shu-sen WU State Key laboratory of Materials Processing and Die ＆ Mould Technology Huazhong University of Science and TechnologyWuhan 430074China

nano-SiCp/A356 composites with different nano-SiCp contents were prepared by squeeze casting after ultrasonic treatment（UT）. The effects of SiCp content on the microstructure and mechanical properties of the nanocomposites were investigated. Theresults show that with the addition of nano-SiCp, the microstructure of nanocomposites is obviously refined, the morphology of theα（Al） grains transforms from coarse dendrites to rosette crystals, and long acicular eutectic Si phases are shortened and rounded. Themechanical properties of 0.5%, 1% and 2% （mass fraction） SiCp/A356 nanocomposites are improved continuously with the increaseof nano-SiCp content. Especially, when the SiCp content is 2%, the tensile strength, yield strength and elongation are 259 MPa,144 MPa and 5.3%, which are increased by 19%, 69% and 15%, respectively, compared with those of the matrix alloy. Theimprovement of strength is attributed to mechanisms of Hall？Petch strengthening and Orowan strengthening.

关键词： nano-SiCp aluminum matrix composites ultrasonic treatment microstructure mechanical properties

Microstructure and mechanical properties of a cast heat-resistant rare-earth magnesium alloy

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China Foundry 2023年第4期20卷 289-298页

作者： Xiao-ping Zhu Jun-qing Yao Hai-long Wu Xin-wang liu Hua liu Zi-tian Fan shu-lin lü Kai Wang Zi-dong Wang School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China State Key laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Dekai Intelligent Casting Co. Ltd.Zhuozhou 072750HebeiChina China Iron and Steel Research Institute Group Beijing 100081China Guangdong Hongtu Wuhan Die-casting Co. Ltd.Wuhan 430207China

Microstructure,mechanical properties and phase transformation of a heat-resistant rare-earth(RE)Mg-16.1Gd-3.5Nd-0.38Zn-0.26Zr-0.15Y(wt.%)alloy were *** as-cast alloy is composed of equiaxedα-Mg matrix,net-shaped Mg5RE and Zr-rich *** to aging hardening curves and tensile properties variation,the optimized condition of solution treatment at 520℃for 8 h and subsequent aging at 204℃for 12 h was *** continuous secondary Mg5RE phase predominantly formed at grain boundaries during solidification transforms to residual discontinuousβ-Mg5RE phase and fine cuboid REH2particles after heat *** annealed alloy exhibits good comprehensive tensile property at 350℃,with ultimate tensile strength of 153 MPa and elongation to fracture of 6.9%.Segregation of RE elements and eventually RE-rich precipitation at grain boundaries are responsible for the high strength at elevated temperature.

关键词： heat-resistant magnesium alloy rare earth microstructure phase transformation tensile property strengthening

Influence of high pressure and manganese addition on Fe-rich phases and mechanical properties of hypereutectic Al-Si alloy with rheo-squeeze casting

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Transactions of Nonferrous Metals Society of China 2019年第2期29卷 253-262页

作者： Chong lin shu-sen WU shu-lin lü He-bao WU Han-xin CHEN Hubei Provincial Key laboratory of Chemical Equipment Intensification and Intrinsic Safety Wuhan Institute of TechnologyWuhan 430205China State Key laboratory of Materials Processing and Die&Mould Technology Huazhong University of Science and TechnologyWuhan 430074China

The influence of high pressure and manganese addition on Fe-rich phases(FRPs)and mechanical properties of Al-14Si-2Fe alloy with rheo-squeeze casting(RSC)was *** semi-solid alloy melt was treated by ultrasonic vibration(UV)firstly,and then formed by squeeze casting(SC).Results show that the FRPs in as-cast SC alloys are composed of coarseβ-Al5(Fe,Mn)Si,δ-Al4(Fe,Mn)Si2 and bone-shapedα-Al15(Fe,Mn)3Si2 phases when the pressure is 0 *** RSC process,the FRPs are first refined by UV,and then the solidification under pressure further causes the grains to become *** peritectic transformation occurs during the formation ofα*** the alloy with the same composition,the ultimate tensile strength(UTS)of RSC sample is higher than that of the SC *** the same forming process,the UTS of Al-14Si-2Fe-0.8Mn alloy is higher than that of Al-14Si-2Fe-0.4Mn alloy.

关键词： high pressure manganese rheo-squeeze casting hypereutectic Al-Si alloy Fe-rich phases mechanical properties

Dry sliding wear behavior of rheocast hypereutectic Al-Si alloys with different Fe contents

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Transactions of Nonferrous Metals Society of China 2016年第3期26卷 665-675页

作者：林冲吴树森吕书林曾劲彪安萍华中科技大学材料成形与模具技术国家重点实验室武汉430074 武汉工程大学机电工程学院武汉430073

The effect of iron content on wear behavior of hypereutectic Al?17Si?2Cu?1Ni alloy produced by rheocasting process was investigated. The dry sliding wear tests were carried out with a pin-on-disk wear tester. The results show that the wear rate of the rheocast alloy is lower than that of the alloy produced by conventional casting process under the same applied load. The fine particle-likeδ-Al4(Fe,Mn)Si2 and polygonalα-Al15(Fe,Mn)3Si2 phases help to improve the wear resistance of rheocast alloys. As the volume fraction of fine Fe-bearing compounds increases, the wear rate of the rheocast alloy decreases. Moreover, the wear rate of rheocast alloy increases with the increase of applied load from 50 to 200 N. For the rheocast alloy with 3% Fe, oxidation wear is the main mechanism at low applied load (50 N). At higher applied loads, a combination of delamination and oxidation wear is the dominant wear mechanism.

关键词： dry sliding wear hypereutectic Al-Si alloy rheocasting Fe-bearing compound wear mechanism

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深冷循环处理对金属玻璃结构和性能的影响

Transactions of Nonferrous Metals Society of China 2023年第10期33卷 2879-2897页

作者：王明梓郭威吕书林吴树森华中科技大学材料科学与工程学院材料成形与模具技术国家重点实验室武汉430074 湖南大学汽车车身先进设计与制造国家重点实验室长沙410082 华中科技大学深圳研究院深圳518057

近期研究表明,金属玻璃可通过热激励或机械激励的方法回春到更加亚稳的高能量状态,同时伴随着原子堆垛的松散化。回春过程可有效提高金属玻璃的宏观塑性。从金属玻璃弛豫与回春概念入手,简要介绍金属玻璃的回春手段,总结不同方法的优缺... 详细信息

近期研究表明,金属玻璃可通过热激励或机械激励的方法回春到更加亚稳的高能量状态,同时伴随着原子堆垛的松散化。回春过程可有效提高金属玻璃的宏观塑性。从金属玻璃弛豫与回春概念入手,简要介绍金属玻璃的回春手段,总结不同方法的优缺点。重点介绍深冷循环热处理(一种对样品形态无破坏性且适用性较高的回春方法)的效果、热处理参数对回春程度的影响以及回春后金属玻璃力学和磁性能的演化规律。最后,就金属玻璃回春行为进行分析,并对未来重要研究方向提出展望。

关键词：金属玻璃回春深冷循环弛豫焓塑性