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镁合金挤压铸造成形机理及实验研究
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摘要
镁合金具有低密度,高的比强度、比刚度,好的减震性、阻尼性,优良的铸造性能、切削加工性能,已经广泛应用于汽车、航空航天、通信等领域,被誉为21世纪“绿色”工程材料。挤压铸造是一种实现铸锻相结合的先进成形工艺,由此工艺生产的铸件晶粒细小、致密度高、缩松小、力学性能优良,已成功应用于铝合金、铜合金等合金的实际生产中。近年来,挤压铸造理论与应用的研究受到越来越多的学者和企业所重视,但关于镁合金挤压铸造成形机理方面的研究确很少,已严重制约了镁合金挤压铸造技术的推广。同时,我国是镁资源大国,也是镁生产大国,镁合金使用具有重要的战略意义。因此,研究镁合金挤压铸造成形机理对推广高性能镁合金铸件的使用具有显著意义和紧迫性。
     论文利用正交试验方法研究了挤压铸造工艺参数中浇注温度、模具温度、挤压速度对不同壁厚镁合金流动性的影响规律。正交试验结果表明,对壁厚4mm以下试样的流动性影响最大的因素是浇注温度,其次是模具温度,挤压速度;对4mm试样的流动性影响最大的因素是模具温度,其次是浇注温度,挤压速度。在镁合金挤压铸造实际生产过程中,浇注温度在700℃到750℃变化时,增加浇注温度对提高AZ91D镁合金的流动性是有利的;对厚壁铸件(3mm和4mm)通过提高模具温度而增加镁合金的充型能力是非常有效;增加挤压速度,合金流动性也有所增加。对镁合金熔液充型停止流动机理进行分析,并采用一种半定量的计算方法来表述镁合金的充型能力,得出镁合金充型长度的半定量数学表达式。
     对金属液充型过程的流体力学分析表明,当金属液以设定的充型速度充型时,充型特性受流体特性(粘度、表面张力)、流道特性(铸件壁厚和内浇道形状)、充型流动距离等因素的影响。数值模拟与实验研究表明,对6mm厚平板,低的充型速度(<186.8mm/s)容易造成金属液流前沿波动较大,充型过程不平稳,同时也降低了合金的流动性,在铸件最后充型部位容易形成浇不足、冷隔等缺陷;高的充型速度(>933.8mm/s)虽然提高了生产效率,但容易形成喷射流,造成卷气缺陷。对12mm平板,在相同的充型速度下,采用扇形内浇道的充型过程比采用矩形内浇道充型平稳,同时扇形内浇道也能以不高的速度完成快速充型,从而避免喷射流的出现。
     对挤压铸造AZ91D镁合金在不同状态下的显微组织、力学性能以及断裂行为进行了测试和分析,得出挤压铸造AZ91D镁合金铸态、T4态和T6态的硬度、屈服强度、抗拉强度力学性能指标随着试样壁厚的增加而减小,而延伸率随着试样壁厚的增加而增加。以8mm厚试样为分析对象,T4处理后的抗拉强度和延伸率分别达到205MPa、7.0%,其中与铸态相比较,延伸率提升幅度较大,硬度和屈服强度略有下降:T6处理后的硬度和屈服强度显著提高,其中屈服强度与T4态相比较,提升幅度为44.2%,抗拉强度也出现小幅提高,但是延伸率则有所下降。铸态AZ91D镁合金断口以脆性断裂为主,断口比较平整,断口出现的撕裂韧窝和撕裂棱数量比较少。经固溶处理处理后,AZ91D镁合金断裂模式为准解理断裂,断口出现了发达的河流花样和由撕裂棱连接的较大解理刻面,而在撕裂棱周围也出现了一些深浅不一的韧窝。经固溶时效处理后,AZ91D镁合金断口中也分布了一些细小的河流花样及少量较浅的韧窝,但断口整体表现为为沿晶断裂。
     通过理论分析与微观组织分析,研究了镁合金间接挤压铸造中冷夹层的形成机理。显微组织分析发现,冷夹层像一层保温膜,将铸件分割为两部分,导致夹层两侧组织明显不同;对冷夹层进行EDS能谱分析表明,冷夹层中高亮质点处主要存在O、Mg、Si三种元素,说明冷夹层中形成了高熔点的氧化物以及冷夹层表面存在污染,冷夹层不易重熔。进一步分析指出消除间接挤压铸造铸件中冷夹层的必须保证浇入到压室内的镁合金液具有一定的过热度,并使冷凝层进入模具型腔时被破碎与重熔。从理论上分析了冷凝层重熔的温度条件并给出了相应的计算公式。适当提高压室温度和浇注温度,可减少压室内冷凝层的厚度,有利于冷凝层的破碎和重熔;在压室内壁均匀涂上一层合适的涂料,降低了压室的导热能力,也可减少冷凝层的厚度;减少镁合金熔液在压室中的停留时间和采用机械方法也可以减少或消除铸件中的冷夹层。
Magnesium alloy is very attractive in such applications as automobile, aerospace and communication industries due to its low density, high specific strength, stiffness, good absorption of vibration and damping, excellent castability and machinability. It is praised as the green engineering material in21st century. Squeeze casting, an advanced forming technology with the combination of casting and forging, has been successfully used in the practical production of aluminum alloy and copper alloy etc. The process has the capability of producing castings which are fine grains, high density, pore free and excellent mechanical property. In recent years, more and more scholars and enterprises pay more attention to the study of theory and application of squeeze casting. But limit researches have been done about the forming mechanism of magnesium alloy squeeze casting. The promotion of the process is seriously restricted. Meantime, magnesium resource and production is very abundant in our country, and the using of magnesium alloy has a very important strategic meaning. Therefore, it is necessary to discuss the forming mechanism of magnesium alloy squeeze casting for the promotion of high-quality castings.
     The influence of pouring temperature, mould temperature and squeeze velocity on the fluidity of magnesium alloy with different wall thickness was investigated using orthogonal test. The experimental results show that the most important factor influencing the fluidity of specimens with1,2and3mm wall thickness is pouring temperature and then mould temperature and squeeze velocity, but for specimen with4mm thickness mould temperature at first, and then pouring temperature and squeeze velocity. In practical production, it is very effective to increase pouring temperature for better filling ability of squeeze cast AZ91D magnesium alloy between700to750℃, but it is not suitable above750℃. But the filling length of magnesium alloy in the thick section (3and4mm) increases remarkably because of the longer filling time. The fluidity of magnesium alloy increases with the increase of squeeze velocity. Based on the stopped-flow mechanism of magnesium alloy, semi-quantitative mathematical expression of the filling length is educed.
     Fluid mechanics analysis on the filling of molten metal shows that the filling characteristic is affected by liquid characteristic (viscosity and surface tension), runner characteristic (wall thickness and shape of ingate) and filling length etc. Numerical simulation and experimental study shows that low filling velocity (<186.8mm/s) can easily cause the great fluctuation of the fluid level, the instability of filling process and the decrease of fluidity for6mm thickness plate. Misrun and cold lap appear in the last filling position. The defects of air entrainment are caused by the jetting of the molten metal at high filling velocity (>933.8mm/s). The filling process is smoother using fanned gate than straight gate at same filling velocity for12mm thickness plate. The fan ingate helps accomplish a rapid fill without high velocities and avoids jetting effects.
     Microstructure, mechanical properties and fracture characteristics of squeeze casting AZ91D alloy under different states are measured and analyzed The results show that hardness, yield strength and tensile strength decrease but elongation increases with the increase of wall thickness under as-cast, T4heat-treating and T6heat-treating. Taking8mm thickness sample as analysis object, tensile strength reaches205MPa, and elongation reaches7.0%in T4heat-treating. Compare with as-cast, elongation increases in large amplitude, but hardness and yield strength drop slightly. Hardness and yield strength significantly increases, tensile strength increases slowly, and elongation drops slightly in T6heat-treating. Compare with T4heat-treating, yield strength increases by44.2%. The fracture mode of squeeze cast AZ91D specimens in as-cast is mainly brittle fracture. A few tearing ridges and dimples with small size are observed on fracture surfaces. The fracture mode of AZ91D specimens in T4heat-treating is a combined fracture of quasi-cleavage and a few dimples. The cleavage surfaces, river markings and dimples are observed on the fracture surfaces. The fracture mode of AZ91D specimens in T6heat-treating is mainly intergranular fracture, and a few shallow dimples and tiny tearing ridges are observed on the fracture surfaces.
     The forming mechanism of cold clamp in squeeze cast AZ91D is discussed by theory analysis and microstructure analysis. The casting is divided into two parts by cold clamp which is like a layer of insulation. Therefore, both sides structures of cold clamp are obviously different. EDS analysis results indicate that high light particles in the cold clamp involve O, Mg and Si three elements. The particles consist of high melting point oxides and contamination from cold clamp surface. Further analysis shows that molten metal must contain superheat, and solidification layer in the pressure chamber must be broken up and remelted when filling cavity in order to eliminate cold clamp. The calculating formula for solidification layer remelting is deduced in the paper. The thickness of solidification layer decreases with the increase of the temperature of pressure chamber and pouring temperature. Thin solidification layer is easy to break up and remelt. A layer of suitable coating is evenly coated in the inner wall of pressure chamber, which can reduce the capacity of heat transmission of pressure chamber and decrease the thickness of solidification layer. Reducing the resident time of molten metal in the pressure chamber and using mechanical method can decrease or eliminate cold clamp.
引文
[1]丁文江.镁合金科学与技术[M].北京:科学出版社,2007.
    [2]徐河,刘静安,谢水生.镁合金制备与加工技术[M].北京:冶金工业出版社,2007.
    [3]黎文献.镁及镁合金[M].长沙:中南大学出版社,2005.
    [4]左铁镛.21世纪的轻质结构材料-镁及镁合金发展[J].新材料产业,2007,12:22-26.
    [5]姜巍巍.镁锂合金表面防腐蚀覆层的研究[D].哈尔滨:哈尔滨工程大学,2007.
    [6]杨艳玲.挤压铸造Mg-Nd(-Zr)合金工艺及凝固行为研究[D].上海:上海交通大学,2010.
    [7]B.L. Mordike, T. Ebert. Magnesium Properties-applications-potential[J]. Material Science Engineering A,2001,302:37-45.
    [8]H. Gjestland and H. Westengen. Advancements in High Pressure Die Casting of Magnesium[J]. ADVANCED ENGINEERING MATERIALS,2007,9:769-776.
    [9]唐全波,黄少东,伍太宾.镁合金在武器装备中的应用分析[J].兵器材料科学与工程,2007,30(2):69-71.
    [10]滕海涛,亚快速凝固条件下镁合金的凝固行为及其应用研究[D].大连:大连理工大学,2009.
    [11]康鸿跃,陈善华,马永平,王忠海.镁合金在军事装备中的应用[J].金属世界,2008,1:61-64.
    [12]Haibo Yang, Xingsheng zhao, Weizhong Fan. Development status and application prospect of squeeze casting technology[J]. Advanced Materials Research,2012,538:1154-1157.
    [13]Md. Nur-Hossain and Farid Taheri. Influence of Elevated Temperature and Stress Ratio on the Fatigue Response of AM60B Magnesium Alloy[J]. Materials Engineering and Performance,2012, 21(7):1395-1404.
    [14]吉泽升,胡茂良.镁合金固相再生与固相合成[M].北京:科学出版社,2011.
    [15]王建军,王智民,白杉.日本镁合金的应用与研究现状[J].中国铸造装备与技术,2006,4:7-10.
    [16]肖冰,康凤,胡传凯.国外轻质结构材料在国防工业中的应用[J].兵器材料科学与工程,2011,34(1):94-97.
    [17]Moiseyrv V N. Titanium alloys russian aircraft and aerospace applications[M]. USA:Taylor & Francis Group,2006.
    [18]丁文江,付彭怀,彭立,等.先进镁合金材料及其在航空航天领域中的应用[J].航天器环境工程,2011,28(2):103-108.
    [19]龙思远,徐绍勇,查吉利,等.镁合金应用与汽车节能减排[J].资源再生,2011,3:48-50.
    [20]宋柯.镁合金在汽车轻量化中的应用发展[J].机械研究与应用,2007,20(1):14-16.
    [21]Mustafa Kemal Kulekci. Magnesium and its alloys applications in automotive industry[J]. Int J Adv Manuf Technol,2008,39:851-865.
    [22]Z Zhen, M Qian, S Ji, Z Fan. Microstructure and mechanical properties of rheo-diecast AZ91D magnesium alloy[J]. Journal of Materials Science,2006,41(12):3631-3644.
    [23]张海峰.镁合金熔体15kHz超声净化工艺及超声凝固的物理模拟[D].沈阳:东北大学,2009.
    [24]余琨,陈良建,雷路,张思慧.镁合金作为生物医用植入材料的研究进展[J].金属功能材料,2009,16(4):61-64.
    [25]张佳,宗阳,付彭怀,等.镁合金在生物医用材料领域的应用及发展前景[J].中国组织工程研究与临床康复,2009,13(29):5747-5750.
    [26]姜海英,艾红军.生物可降解镁合金植入材料的医用特征[J].中国组织工程研究与临床康复,2011,15(34):6411-6414.
    [27]Thomann M, Krause C, Angrisani N, et al. Influence of amagnesium-fluoride coating of magnesium-based implants (MgCa0.8) on degradation in a rabbit model. J Biomed Mater Res A,2010,93(4):1609-1619.
    [28]彭勇,王顺成,郑开宏,等.高性能镁合金铸造技术研究进展[J].铸造技术,2013,34(2):203-207.
    [29]Henry Hu, Alfred Yu,Naiyi Li, et al. Potential magnesium alloys for high temperature die cast automotive applications:A review[J]. Materials and manufacturing Processes,2003, 18(5):687-717.
    [30]刘好增,罗大金.镁合金压铸工艺与模具[M].北京:中国轻工业出版社,2010.
    [31]C.H. Caceres, W.J. Poole, A.L. Bowles, C.J. Davidson. Section Thickness, Macrohardness and Yield Strength in High-pressure Diecast Magnesium Alloy AZ91[J]. Mater. Sci. Eng. A, 2005,402:269-277.
    [32]H.R.Hashemi, H.Ashoori, Davami. Microstructure and tensile properties of squeeze cast Al-Zn-Mg-Cu alloy[J]. Materials Science and technology,2001,17(6):639-644.
    [33]历长云,王英,张锦志.特种铸造[M].哈尔滨:哈尔滨工业大学出版社,2013.
    [34]米国发,赵恒涛.低压铸造升液管的研究与应用[J].航天制造技术,2007,4:56-59.
    [35]黄天佑,黄乃瑜,吕志刚.消失模铸造技术[M].北京:国防工业出版社,2004.
    [36]M. Khodai, S. M. H. Mirbagheri. Behavior of Generated Gas in Lost Foam Casting[J]. Engineering and Technology,2011,50:479-483.
    [37]Samson Shing Chung Ho. Lost Foam Casting of Periodic Cellular Materials with Aluminum and Magnesium Alloys[D]. Toronto:University of Toronto,2009.
    [38]罗守靖,程远胜,单巍巍.半固态金属流变学[M].北京:国防工业出版社,2011.
    [39]滕海涛,熊柏青,张永安,等.铝、镁合金半固态浆料的制备与流变成形新工艺[J].中国有色金属学报,2012,22(4):1019-1024.
    [40]李东南,吴和保,吴树森,罗吉荣.半固态AZ91D镁合金组织与性能研究[J].,中国机械工程,2006,17(13):1421-1425.
    [41]王国伟,巫瑞智Al-6.5%Mg合金的半固态流变铸造及其性能[J].中国有色金属学报,2012,22(1):33-38.
    [42]罗守靖,陈炳光,齐不骧.液态模锻与挤压铸造技术[M].北京:化学工业出版社,2007.
    [43]H. Hu. Squeeze Casting of Magnesium Alloys and Their Composites[J]. Journal of Materials Science,1998,33:1579-1589.
    [44]German Gertsberg, Ei Aghion, Ali Arslan Kaya, Dan Eliezer. Advanced Production Process and Properties of Die Cast Magnesium Composites Based on AZ91D and SiC[J]. Journal of Materials Engineering and Performance,2008,18(7):886-892.
    [45]罗继相,李敏华.挤压铸件品质的综合研究[J].特种铸造及有色合金,2006,26(11):715-718.
    [46]陈云,罗继相,陈定方.双分型面挤压铸造模具设计[J].特种铸造及有色合金,2007,27(4):281-283.
    [47]Sunghak Lee, Seung Hyuk Lee, Do Hyang Kim. Effect of Y, Sr, and Nd Additions on the Microstructure and Microfracture Mechanism of Squeeze-Cast AZ91-X Magnesium Alloys[J]. Metallurgical and Materials Transactions A,1998,19(4):1221-1235.
    [48]Ming Zhou, Henry Hu, NaiyiLi and Jason Lo. Microstructure and Tensile Properties of Squeeze Cast Magnesium Alloy AM50[J]. Journal of Materials Engineering and Performance, 2005,14 (4):539-545.
    [49]A. Srinivasan, U.T.S. Pillai, and B.C. Pai. Microstructure and mechanical properties of Si and Sb added AZ91 magnesium alloy[J]. Metallurgical and Materials Transactions A,2005, 36(8):2235-2243.
    [50]M.S.Yong, A.J.Clegg. Process optimization for a squeeze cast magnesium alloy[J]. Journal of Materials Processing Technology,2004,145:134-141.
    [51]廖慧敏,龙思远,石光华.压铸镁合金方向盘裂纹的分析及防止[J].铸造,2008,57(9):974-977.
    [52]廖慧敏,龙思远.挤压铸造镁合金轮毂浇注系统的数值模拟[J].特种铸造及有色合金,2008,28(4):271-273.
    [53]李荣德,于惠舒,李晨希,白彦华,于宝义.比压对大高径比挤压铸造ZA27合金杯形铸件的组织与性能的影响[J].铸造,55(3):245-248.
    [54]肖泽辉,罗吉荣,吴树森,等.镁合金挤压铸造成形的研究[J].铸造,2003,52(9):672-674.
    [55]红霞,王宁.AZ91D合金的挤压铸造工艺及性能[J].内蒙古工业大学学报(自然科学版),2006,25(1):30-34.
    [56]杨军生.干砂消失模铸造铝合金充型特性的研究[D].北京:清华大学,1995.
    [57]Wang Qudong, Lu Yizhen, Zeng Xiaoqin, Ding Wenjiang. Study on the fluidity of AZ91_xRE magnesium alloy[J], Material Science Engineering A,1999,271:109-115.
    [58]薛寒松,李华基,王勇勤.薄壁件差压铸造的充型特点及影响因素[J].重庆大学学报,2002,25(10):20-22.
    [59]周中波,李金山,寇宏超,等.工艺参数对低压铸造薄壁件充型能力的影响[J].特种铸造及有色合金,2008,28(1):23-25.
    [60]Wang C, Ramsay C W, Askeland D R. Processing variable significance on filling thin plates in the LFC process —the staggered, nested factorial experiment[J]. AFS Trans,1997, 105:427-434.
    [61]Liu Z, Hu J, Ding W, et al. Effect of processing parameters on mold filling in magnesium alloy EPC process[J]. AFS Trans,2001,109:1425-1438.
    [62]吴国华,罗吉荣.消失模铸造铝液充型速度研究[J].特种铸造及有色合金,2000,20(1):26-27.
    [63]吴和保.可控气压下镁合金消失模铸造充型凝固特征的基础研究[D].武汉:华中科技大学,2005.
    [64]Fuqiang Ying, Hongqiang Tang, Tinghong Peng. Numerical Simulation of Low Pressure Die-cast of Magnesium Alloy Wheel[C]. The 7th International Conference on System Simulation and Scientific Computing, beijin,2008,736-739.
    [65]E. Aghion, N. Moscovitch, and A. Amon. Mechanical Properties of Die-Cast Magnesium Alloy MRI 230D[J]. Material Engineering and Performance,2009,18(7):912-916.
    [66]付彭怀,王渠东,蒋海燕,等.镁合金熔炼技术研究进展.铸造技术,2005,26(6):489-492.
    [67]张诗昌,魏伯康,林汉同.镁合金中的MgO夹杂物及熔剂精炼过程的研究[J].铸造,2003,52(7):488-491.
    [68]耿浩然,滕新营,王艳,王桂清.铸造铝、镁合金[M].北京:化学工业出版社,2006.
    [69]赵选民.试验设计方法[M].北京:科学出版社,2006.
    [70]李云雁,胡传荣.试验设计与数据处理.北京:化学工业出版社,2009.
    [71]Lin Shengjun, Zhao Wei, Li Yuan, Tong Siyi and Wang Wenqing. Optimization of tensile strength for new type acetone-urea-formaldehyde furan resin using uniform design[J]. China Foundry,2011,8(1):30-35.
    [72]马重芳,陈永昌.自由表面二维平面射流冲击传热的理论分析[J].北京工业大学学报,2000,26(3):59-62.
    [73]Tasos C. Papanastasiou, Georgios C. Georgiou, Andreas N. Alexandrou. Viscous fluid flow[M]. Florida:CRC Press,2000:197-206.
    [74]黄皓,付彭怀,彭立明,等.模具温度和浇注温度对AZ 91D镁合金热裂和流动性能的影响[J].特种铸造及有色合金,2012,32(1):81-84.
    [75]赖华清,徐纪平,陆文龙.压铸工艺与模具[M].北京:机械工业出版社,2011.
    [76]王岩,隋思涟.试验设计与MATLAB数据分析[M].北京:清华大学出版社,2012.
    [77]罗继相,胡建华,谌伟,白旭白.挤压铸造金属液流充型特性研究[J].武汉理工大学学报,2003,25(2):23-26.
    [78]熊守美.铸造过程数值模拟仿真技术[M].北京:机械工业出版社,2011.
    [79]姚望舒商琳陈兆乾.一种基于进化算法的连续属性离散化方法[J].计算机应用与软件,2005,22(3):37-39.
    [80]Zhao Zhiyong, Hu Jianwei. The upwind finite element scheme and maximum principle for nonlinear convection-diffusionproblem[J]. Journal of Computational Mathematics,2004, 22(5):699-718.
    [81]廖敦明,刘瑞祥,陈立亮,林汉同.丛于有限差分法的铸件凝固过程热应力场数值模拟的研究[J].铸造,2003,52(6):420-425.
    [82]甘艳,阮江军,张宇.有限元法与有限体积法相结合处理运动电磁问题[J].中国电机工程学报,2006,26(14):145-150.
    [83]方异峰,龙思远,曹韩学,廖慧敏.横浇道几何特征对镁合金挤压铸造流态影响的数值模拟[J].特种铸造及有色合金,2010,30(1):39-42.
    [84]汪煦,赵玉涛,苏大为ProCAST在金属型重力铸造充型和模具温度场中的应用[J].铸造,2008,57(12):1263-1266.
    [85]李敏华,罗继相,赵利华,黄国庆.挤压铸造舵面的液流充型过程数值模拟[J].特种铸造及有色合金,2006,26(12):772-774.
    [86]田光辉,高鹏.压铸模内浇口的设计分析[J].模具制造,2002,11(16):33-36.
    [87]付振南,熊守美.铸造镁合金AZ91D金相腐蚀方法研究[J].特种铸造及有色合金,2007,27(7):496-498.
    [88]李东南,范新风,翁瑞珠,等.AZ91 D镁合金挤压铸造组织与性能的研究[J].铸造技术,2006,27(3):273-275.
    [89]Wang Qudong, Chen, Wenzhou, Zeng Xiaoqin, et al. Effects of Ca addition on the microstructure and mechanical properties of AZ91 magnesium alloy[J]. Journal of Materials Science,2001,36 (12):3035-3040.
    [90]张菊梅,蒋白灵,王志虎.固溶和时效对AZ80镁合金断裂行为的影响.特种铸造及有色合金,2007,27(9):663-665.
    [91]麻彦龙,彭东华,潘成东,秦旭,杜勇.热处理对AZ91D镁合金显微组织的影响[J].热加工工艺,2008,37(10):50-53.
    [92]A. Maleki, B. Niroumand, A. Shafyei. Effects of squeeze casting parameters on density, macrostructure and hardness of LM13 alloy[J]. Materials Science and Engineering A,2006, 428:135-140.
    [93]M. Munawar Chaudhri. Indentation Size Effect and the Hall-Petch 'Law'[J]. Materials Science Forum,2010,662(13):13-26.
    [94]Henry Hu, Alfred Yu. Numerical Simulation of Squeeze Cast Magnesium Alloy AZ91 D[J]. Modelling Simul. Mater. Sci. Eng,2002,10:1-11.
    [95]杨友,刘勇兵,杨晓红.AZ91系列压铸镁合金高周疲劳断口形貌分析[J].铸造,2006,55(2):135-139.
    [96]张菊梅,蒋白灵,王志虎,等.固溶和时效对AZ80镁合金断裂行为的影响[J].特种铸造及有色合金,2007,27(9):663-665.
    [97]YUAN GUANGYIN, WANG QUDONG, DING WENJIANG High temperature deformation behavior of permanent casting AZ91 alloy with and without Sb addition[J]. JOURNAL OF MATERIALS SCIENCE,2002,37:127-132.
    [98]Li Zhifeng, Li Zhenming, Fu Penghuai. Study on High Cycle Fatigue Behavior of Gravity Cast Mg-3Nd-0.2Zn-Zr Magnesium Alloy[J]. Rare Metal Materials and Engineering,2012, 41(9):1592-1596.
    [99]Val y. Gertsman, Jian Li, Su Xu, James P. Thomson, and Mahi Sahoo. Microstructure and Second-Phase Particles in Low-and High-Pressure Die-Cast Magnesium Alloy AM50[J]. METALLURGICAL AND MATERIALS TRANSACTIONS A,2005,36(8):1989-1995.
    [100]马颖,潘振峰,张洪峰,等.热处理对AZ91D镁合金组织及力学性能的影响[J].兰州理工大学学报,2009,5(35):9-12.
    [101]X.S. Wang and J.H. Fan. An Evaluation on the Growth Rate of Small Fatigue Cracks in Cast AM50 Magnesium Alloy at Different Temperatures in Vacuum Conditions[J]. Int. J. Fatigue,2006, 28:79-86.
    [102]J. P. WEILER*, J. T. WOOD, R. J. KLASSEN. The effect of grain size on the flow stress determined from spherical microindentation of die-cast magnesium AM60B alloy. JOURNAL OF MATERIALS SCIENCE,2005,40:5999-6005.
    [103]张菊梅,王志虎,将白灵.T6处理对AZ91镁合金析出相P-Mg17A112及断裂性能的影响[J].热加工工艺,2011,40(2):153-156.
    [104]Y, Lu, F. Taheri, and M. Gharghouri. Study of Fatigue Crack Incubation and Propagation Mechanisms in a HPDC AM60B Magnesium Alloy[J]. J. Alloys Compd.,2008,466:214-227.
    [105]邢书明,鲍培伟,于冬,王硕.钢铁零件挤压铸造的工业化应用[J].特种铸造及有色合金,2012,32(1):30-33.
    [106]赵祖德,王少纯等.AZ31镁合金静液挤压试验研究[J].中国机械工程,2008,19(9):1111-1115.
    [107]于海朋,王利波,于宝义,王影.浇注温度对间接挤压铸造A125Cu合金的影响[J].特种铸造及有色合金,2012,26(1):43-45.
    [108]HAITHAM EL KADIRI, M.F. HORSTEMEYER, J.B. JORDON, and YIBIN XUE. Fatigue Crack Growth Mechanisms in High-Pressure Die-Cast Magnesium Alloys[J]. METALLURGICAL AND MATERIALS TRANSACTIONS A,2008,39(1):190-205.
    [109]W.D. GRIFFITHS and N.-W. LAI. Double Oxide Film Defects in Cast Magnesium Alloy[J]. METALLURGICALAND MATERIALS TRANSACTIONS A,2007,38(1):190-196.
    [110]E. Aghion, N. Moscovitch, and A. Arnon. Solidification Characteristics of Newly Developed Die Cast Magnesium Alloy MR Ⅱ 53M[J]. Material Science Technology,2007, 23(3):270-275.
    [111]Adrian S. Sabau, Predicting Interdendritic Cavity Defects during Casting Solidification[J]. JOM,2004,4:54-56.
    [112]吴夏玲,破碎机锤头液态模锻模具设计与成形实验研究[D].北京:北京交通大学,2007.
    [113]赵宇,刘盼盼,周宏.AZ91D镁合金中的夹杂物[J].铸造技术,2006,27(8):834-838.
    [114]司季青.压力铸造中涂料的选择和喷涂工艺[J].机械工人,2006,6:79-80.
    [115]林柏年,魏尊杰.金属热态成形传输原理[M].哈尔滨:哈尔滨工业大学出版社,2000.
    [116]罗继相,赵利华,谢少庆,等.挤压铸造实用技术研究[J].特种铸造及有色合金,2005,25(3):150-152.
    [117]邓建新,邵明,游东东.挤压铸造设备现状及发展分析[J].铸造,2008,57(7):643-646.

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