半固态压铸件ADC12铝合金的可行性毕业论文外文翻译.doc

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1、半固态压铸件ADC12铝合金的可行性1。采矿和材料工程专业,工程学院,大学Songkla王子2。工业工程专业,工程学院, 科技大学Rajamangala Srivijaya3。机械工程学系,工程学院,大学Songkla王子2010年5月13日至2010年6月25日文摘研究半固态压铸件ADC12铝合金的可行性。已经确定活塞速度受壁厚和固态粒度缺陷的影响。研究表明缺陷是由缩松引起的。在实验中,采用的是半固态浆料制备半固态gas-induced(GISS)的技术。然后,液态金属被转移到压铸模具之中,模具和套筒温度分别保持在180 C和250 C结果表明,GISS制作的压铸模具松孔较小没有气泡微观结构

2、均匀。实验结果表明并可以推论,GISS是可行的,适用于ADC12铝压铸过程。另外 GISS可以改进性能比如减少孔隙度和增加组织均匀性。关键词:ADC12铝合金;半固态压铸;气体引起的半固态(GISS); 流变铸造第1章在电子、航天、和建筑领域。多年来一直使用铝制部件这些部件通常使用高压压铸过程大量生产。压铸过程的优点在于实现了如生产效率高和生产小且复杂的工件压铸过程包括将铝液在高压下注入到一个模具型腔中。金属液灌到模具型腔中,导致金属反应和铸造的过程中产生气孔。因此,最终的结构部分充满气泡和氧化物夹杂。此外，压铸件通常不能进行加工,由于这些缺陷的产生要进行阳极氧化、焊接、热处理,1-4。来提高

3、的压铸过程质量和性能因此在这里介绍了半固态金属技术。大量的半固态压铸的研究报道,使用半固态压铸有助于改善产品性能和提高质量的压铸零件5-7。半固态金属加工过程使用流变路线可以提供更高粘度的液体与更高的粘度, 能够获得更少的湍流流动,这有助于减少空气孔隙度和氧化物夹杂在模具填充5-7。此外,流变过程可以很容易被应用 于传统的压铸模具的生产过程,只需要少量修改便可使效率提高8。许多研究显示成功的半固态压铸与流变过程7-12。然而,大多数的工作已经使用了A356,A357,ADC10铝合金。尽管ADC12现已广泛用于压铸行业,但是还没有完整的研究的半固态成形铝合金已发表。ADC12铝合金的好处是具有

4、良好的流动性优秀的铸造性能和高机械性能。 不会导致气孔缺陷,通常也不会因为在高温下进行表面热处理而引起起泡和毛孔扩张13-14。ADC12铝合金也因此被选中来研究半固态压铸过程。a本研究的主要目标是其可行性1)处理的铝合金半固态ADC12使用气体引起的半固态(GISS)技术和2)半固态压铸的商业部分。2 试验本研究中用到的材料是商业ADC12铝合金。这种合金熔点温度是582度。这种合金的共晶温度是572 c .化学成分测试使用光谱仪(翻译)表1所示。表1的化学成分铝ADC12合金(质量分数)SiFeCuMnMgZn11.880.931.750.120.070.78TiCrNiPbSnAl0.0

5、60.030.110.060.01Bal.2.1半固态浆料制备在这个实验中,坩埚中ADC12铝合金在通过电力炉加热到100摄氏度以上达到熔点温度( 680 C). 坩埚中大约200 g的铝合金融化。接下来, 注入的氮气通过石墨扩散，熔融温度约为590摄氏度。注入气体时间分别为5、10、15秒。Fig.1显示实验全过程.在不同的注入时间里,利用快速淬火的方法对固体组分进行了分析.在一定的温度高冷却速率下能够观察到铜模具微观结构15 16。样品的微观结构从不同的流变铸造时间来计算固体部分。用Photoshop和图像工具软件分析16。图1示意图气体引起的半固态(GISS)过程2.2压铸过程铝液由GI

6、SS过程被转移到压铸机器。这种压铸机 具有80吨夹紧系统。液态金属进入干套的温度保持在在250摄氏度。 液态金属进入压铸模具速度为0.05,0.1和0.2米/秒。模具温度保持在180 C。原理图的GISS压铸过程图2所示。在这项研究中,孔隙度、表面缺陷、表面疱、宏观和微观结构研究的样本。总结本研究中所用的参数是表2所示。图2中GISS压铸过程的示意图2.3压铸成分分析分析方法的简要描述如下。1）孔隙度分析样品的密度(DL)测定DS是铝合金ADC12的标准密度密度为2.76克/立方厘米);DL是密度从Eq。(1)。2) 表面缺陷和起泡的测试观察表面缺陷的样品是压铸过程之后进行的。本研究中观察到的

7、缺陷是冷关闭和起泡缺陷。样品在浸泡480度12小时后进行评估。3) 宏观缺陷样品的切面图见图3。接下来,这些样品进行320、800和1200处理后观察宏观缺陷。4) 组织均匀性使用光学显微镜不同部位的显微组织观察样品。切削样品如A,B,C,D图所示。然后准备金相分析用标准的研磨、抛光、蚀刻程序表2总结本研究中使用的参数Fig.3图 流变增加时间部分3的结果和讨论从获得的结果表明,你将产生的条件下的流变铸造时间为5、10、15秒分别为固体组成部分的0.25%、6.33%和13.03%。代表的微观结构在不同时期流变淬火样本显示在图4。照片主要说明随a（白阶段）增加而增加的流变铸造时间当固态粒度增加

8、时浆料的粘度应该随之增加。可以推论,在理想的固体状态下ADC12铝合金做成的半固态浆料在 不同流变过程中使用GISS过程。3.2压铸过程一个代表性样本所产生的半固态图4代表显微组织样品在不同时期流变铸造时间:(一)5 s;(b)10秒;(c)15秒压铸过程如图5所示示例包括三个溢流槽,浇道,和一个手柄。多数样品有完整的金属填充溢出和良好的表面光洁度。只有样品和较高的固态粒度有冷隔缺陷如表3所示,代表样本与冷隔缺陷显示在图7。图5的图片代表压铸部分 图7表面缺陷的铸造:(a)浇不足;(b)冷隔高固体分数引起的粘度泥浆更高。薄膜(3毫米),高粘度泥浆很难流入模具,金属无法完全填补整个型腔。此外,由

9、于高固体组分凝固时间较短导致了冷隔缺陷的产生3.3孔隙度分析表3总结压铸的结果M是浇不足，C是冷隔缺陷。结果表明,样品所产生的液体压铸和半固态压铸过程的孔隙度大约分别为5%和1.7%。图7样品孔隙度产生过程比较。然而,在不同条件下半固态压铸样本的孔隙度大小和速度差异没有显著的不同。图7的孔隙度在不同条件下的样本总之在液态铸造中涡流的存在导致样品的气孔缺陷的产生相比之下,所有的半固态压铸的样品比液体压铸中由于涡流导致的孔隙度低。式样因为较小的流动速度而产生较少的气孔3.4 Macrodefect分析所有半固态压铸制作的样品都产生了缩松。此外,气体样本中发现的气孔是压铸生产的液体所产生的,如表3所

10、示。缩松和气孔如Fig.8所示可以得出结论,缩松和气孔的尺寸较大影响宏观缺陷。更大的开口可以帮助减少湍流和改善供料,这减少了缩松。3.5表面起泡表面起泡之后通过对大约一半的样本进行热处理解决问题。这种缺陷主要存在于样品所产生的液体压铸和半固态压铸用的浇道口。相反,当厚门是用于半固态压铸,只有样本编码SSM2-8和SSM2-9有缺陷,如表3所示,如图9所示。总之,找到的缺陷的起泡在半固态压铸可以减少增加固态粒度的大小。Fig.8宏观视图的横截面的样本:(一)液体铸造然而,固态粒度应该不会过高,因为它将很难注入到模具中。3.6微观组织分析代表微结构的样品生产的液态压铸和半固态压铸Fig.10所示。

11、在液体压铸过程中样品的显微结构呈现出树状。半固态压铸过程中样本的微观结构包括原发性a相a相结构z在生长过程中使得模具的规,微观结构在位置A,B,C,D是 相同的模越来越大，a相共晶转变由于冷却速度的增大而不断增大，观察组织均匀性的不同位置Fig.11所示。获得的显微图说明在样品表面如图泡:(一)液态压铸;(b)SSM1-1;(c)SSM2-6 Fig.10样品的微观结构从液态压铸(a)和(b半固态压铸件) Fig.11微观结构在不同位置的代表样本:(一)点;(b)b点;(c)c点;(d)d点4总结1) 使用气体引起的半固态工艺 生产半固态ADC122) 增加固态粒度的泥浆和孔隙度的收缩可以减少

12、零件缺陷。3) 好的半固态压铸铸件需要合适的柱塞速度和固体分数浆。4) 铸造零件制作样品的微观结构是全国统一的。参考文献1 坎贝尔j .铸造M。牛津:Butterwort-Heinemann,1991:1 85。2 郑J,王建民问,赵P,吴c .优化工艺参数的高压压铸用人工神经网络J。先进制造技术,2009年,674年44:667。3VERRAN G O, MENDESB P K, ROSSIC M A. 影响注塑参数对缺陷的形成Al12Si13Cu压铸合金:实验结果和数值仿真J。材料加工技术,2006年,179:190。4HANGAI Y, KITAHARA S. 定量评价孔隙率的铝合金压铸

13、件用分形分析区域的空间分布J。材料和设计,2009年,30:1169 1173。5KIRKWOOD D H, SUERY M, KAPPANOR P, ATKINSON H V,YOUNG K P. 半固态加工合金M。纽约:施普林格,2009。6FLEMING M C.金属合金半固态的行为J。冶金交易,1991年,22:957 981。7FAN Z, FANG X, JI S. 组织和性能的rheo-diecast(RDC)铝合金J。材料科学与工程,2005,412,298。8HONG C P, KIM J M. 开发先进流变过程及其应用J。固态现象,2006年,116/117:44 53。9

14、UBE Industries Ltd. 方法与装置塑造半固态金属:EPO 745694 A1P。1996年12 04。10JORSTAD J, THIEMAN M, KAMM R. SLC: 最新的和最经济的方法来半固态金属(SSM)铸造C/ /第七届国际会议的半固态合金及复合材料加工。日本筑波,2002:701。11YURKO J A, MARTINEZ R A, FLEMING M C. 半固态金属流变的发展过程(SSR)C/ /第七届国际会议的合金半固态加工和复合材料,日本筑波,2002:701。12WANNASIN J, JUNUDOM S, TATTANOCHAIKUL T, FLE

15、MINGM C. 气体引起的发展过程的半固态金属铝压铸应用J。固态现象,200813TIANA C, LAMB J, van der TOUWC J, MURRAYA M, YAOD J Y,GRAHAMD D, JOHND D S T. 融化的影响清洁形成的孔隙度缺陷汽车铝高压压铸件J。杂志的材料加工技术,2002年,122:82。14ZHAO H D, WANG F, LI Y Y, XIA W. 实验和数值分析的气体在板ADC12诱捕缺陷J.压铸件。材料加工技术,2009年,209:4537。 15 WANNASIN J, CANYOOK R, BURAPA R, FLEMING M C

16、.评估铝压铸件在流变过程中的固体部分 16MARTINEZ R A, FLEMING M C. 进化的粒子形态在半固态加工J。冶金材料交易一,2005年,36:2205 2210。附录C 外文文献Feasibility of semi-solid die casting of ADC12 aluminum alloy S. JANUDOM1, T. RATTANOCHAIKUL1, R. BURAPA2, S. WISUTMETHANGOON3, J. WANNASIN11. Department of Mining and Materials Engineering, Faculty of

17、Engineering, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand;2. Department of Industrial Engineering, Faculty of Engineering, Rajamangala University of Technology Srivijaya, Songkhla, 90000, Thailand;3. Department of Mechanical Engineering, Faculty of Engineering, Prince of Songkla

18、University, Hat Yai, Songkhla, 90112, ThailandReceived 13 May 2010; accepted 25 June 2010AbstractThe feasibility of semi-solid die casting of ADC12 aluminum alloy was studied. The effects of plunger speed, gate thickness, and solid fraction of the slurry on the defects were determined. The defects i

19、nvestigated are gas and shrinkage porosity. In the experiments, semi-solid slurry was prepared by the gas-induced semi-solid (GISS) technique. Then, the slurry was transferred to the shot sleeve and injected into the die. The die and shot sleeve temperatures were kept at 180 C and 250 C, respectivel

20、y. The results show that the samples produced by the GISS die casting give little porosity, no blister and uniform microstructure. From all the results, it can be concluded that the GISS process is feasible to apply in the ADC12 aluminum die casting process. In addition, the GISS process can give im

21、proved properties such as decreased porosity and increased microstructure uniformity. Key words: ADC12 aluminum alloys; semi-solid die casting; gas induced semi-solid (GISS); rheocasting 1 IntroductionFor many years aluminum parts have been used in several applications such as automotive, electronic

22、, aerospace, and construction fields. These parts are generally produced in a large quantity by the high pressure die casting process. Several advantages of die casting process have been realized such as high production rate and the ability to form small complex parts. The die casting process involv

23、es the injection of liquid aluminum into a die cavity under high pressures. The metal stream “sprays” into the die cavity, causing metal reaction and air entrapment inside the casting. Therefore, the final parts have a structure which is full of gas bubbles and oxide inclusions. Furthermore, pressur

24、e die casting parts typically cannot be machined, anodized, welded, and heat treated because of these defects14.To improve the quality and properties of the die casting process, semi-solid metal technique has been introduced. A lot of semi-solid die casting studies have reported that using semi-soli

25、d die casting helps to improve the properties and increase the quality of die casting parts57. Semi-solid metal forming using therheocasting route can provide higher viscosity of thefluid. With the higher viscosity, less turbulent flow couldbe obtained, which helps to reduce air porosity and oxide i

26、nclusions during the die filling57. In addition, a rheocasting process can be easily applied with the conventional die casting process because the die casting machine only requires minor modifications8.Many research studies have shown successes in the semi-solid die casting with a rheocasting proces

27、s712. However, most work have used the A356, A357, and ADC10 aluminum alloys. Despite ADC12 is used widely in the die casting industry, no complete research about semi-solid forming of this aluminum alloy has been published yet. The benefits of ADC12 aluminum alloy are good fluidity, excellent casta

28、bility and high mechanical properties. In contrast, it is easy to have turbulent flow, which causes porosity defect, and it cannot normally be heat treated because of the surface blister and the pore expansion at hightemperatures1314.To solve the problems of ADC12 aluminum alloy, a semi-solid die ca

29、sting process is selected to study in this work. The main objectives of this research are to study the feasibility of 1) the semi-solid processing of ADC12 aluminum alloy using the gas induced semi-solid (GISS) technique and 2) the semi-solid die casting of a commercial part.2 ExperimentalThe materi

30、al used in this study is commercial ADC12 aluminum alloy. The liquidus temperature of this alloy is 582C. The eutectic temperature of this alloy is 572C.The chemical composition measured using the optical emission spectrometer (OES) is shown in Table 1.Table 1.Chemical composition of aluminum ADC12

31、alloy (mass fraction, %)SiFeCuMnMgZn11.880.931.750.120.070.78TiCrNiPbSnAl0.060.030.110.060.01Bal.2.1 Semi-solid slurry preparationIn this experiment, an ADC12 aluminum alloy was melted in the graphite crucible in an electrical furnace at about 100 C above the liquidus temperature (680 C). Approximat

32、ely 200 g of the melt was taken from the crucible using a ladle. Next, the nitrogen gas was injected through a graphite diffuser into the ladle when the temperature of the melt was about 590 C. The times to inject the gas were 5, 10 and 15 s. The schematic diagram of the GISS process is shown in Fig

33、.1. At the varied injection times, the solid fractions were analyzed using the rapid quenching method. The high coolingrates achieved by the copper mold allow the capture of the microstructure at a certain temperature1516.The microstructure of the samples from different rheocasting times was used to

34、 calculate the solid fraction. The Photoshop and Image Tool Software were used in the analysis16.2.2 Die casting processThe aluminum slurry prepared by the GISS process was transferred to the die casting machine. This machine has 80t capacity for the clamping system. The slurry was poured into the s

35、hot sleeve kept at the temperature of 250 C. The plunger forced the slurry into the die at various speeds of 0.05, 0.1 and 0.2m/s. The die temperature was kept at 180C. The schematic diagram of the GISS die casting process is illustrated in Fig.2. In this study, the porosity, surface defect, surface

36、 blister, macro- and micro-structure of the samples were investigated. A summary of the parameters used in this study is illustrated in Table 2. Fig.1 Schematic diagram of gas induced semi-solid (GISS) processFig.2 Schematic diagram of GISS die casting process2.3 Die casting part analysisThe analysi

37、s methods are briefly described as follows.1) Porosity analysisThe density of the sample (DL) was measured using Eq.(1), and Eq.(2) was used to calculate the porosity ():where DS is the standard density of an ADC12 aluminum alloy (2.76 g/cm3); DL is the density from Eq.(1).2) Surface defect and blis

38、tering testObservation of the surface defect of the samples was conducted after the die casting process. The defects observed in this study were cold shut and blistering defects. The blistering was evaluated after the samples passed the solution treatment at 480C for 12h.3) Macro defectsAll the samp

39、les were cut at the center as shown in Fig.3. Next, the samples were ground with the 320, 800, and 1200 grit papers to observe the macro defects.4) Microstructure uniformityThe microstructure at different positions of the samples was observed using an optical microscope. The samples were cut and obt

40、ained from positions A, B, C, and D as shown in Fig.3. The samples were then prepared for metallographic analysis using standard grinding, polishing and etching procedures. Table 2 Summary of parameters used in this studyFig.3 Drawing of increased rheocasting time part3 Results and discussion 3.1 Se

41、mi-solid slurry From the obtained results, the slurries produced by the conditions of the rheocasting times of 5, 10 and 15 s have the solid fractions of 0.25%, 6.33%, and 13.03%, respectively. The representative microstructures of the quenched samples at different rheocasting times are shown in Fig

42、.4. The micrographs illustrate that amount of the primary (Al) (white phase) increases with increased rheocasting time. The viscosity of the slurry should be increased when the solid fraction is increased. It can be concluded that the ADC12 aluminum alloy can be produced into a semi-solid slurry at

43、a desired solid fraction by varying the rheocasting time using the GISS process. 3.2 Die casting processA representative sample produced by the semi-solidFig.4 Representative micrographs of samples at different rheocasting times: (a) 5 s; (b) 10 s; (c) 15 sdie casting process is shown in Fig.5. The

44、sample consists of three overflows, a runner, and a biscuit. Most samples had complete metal filling in the overflow and good surface finish. Only the samples produced with a higher solid fraction had the cold shut defect as shown in Table 3 and the representative samples with the cold shut defect i

45、s shown in Fig.6. Fig.5 Representative picture of die casting part Fig.6 Surface defect of casting: (a) Misrun; (b) Cold shutThe high solid fractions cause the viscosity of the slurry higher. For the thin gate (3 mm), the high viscosity slurry was difficult to flow into the die so that the metal cou

46、ld not fill the part completely. In addition, the cold shut defect was found because of the shorter solidification time of the higher solid fractions. 3.3 Porosity analysis The results show that the samples produced by the Table 3 Summary of die casting resultLiquid die casting and the semi-solid di

47、e casting processes have the porosity of about 5% and 1.7%, respectively. The porosities of the samples produced by both processes are compared in Fig.7. However, in the semi-solid die casting samples, the result of the porosity of different conditions of gating size and velocity are not significantly different. Fig.7 Porosity of samples under different conditionsIn summary, in the liquid casting, turbulent flow is present, which results in porosity defect in the samples. In contrast, all the semi-solid die casting samples have lower porosity than the liquid die casting due to the le