Mn对Al-Mg-Si-Cu铝合金结晶相的影响

通过扫描电镜/能谱、 X射线衍射以及金相分析, 针对含0.3?(质量分数)的Al-Mg-Si-Cu铝合金, 研究了Mn含量对其结晶相的影响. 研究表明: 合金在铸造过程中形成的结晶相为Al1.9CuMg4.1Si3.3, Al5(FeMn)Si, Al8(FeMn)2Si以及少量的Mg2Si; 增大含Mn量, 合金中AlFeMnSi型结晶相数量增多; 对合金进行均匀化处理时, Al1.9CuMg4.1Si3.3相完全溶解, 发生Al5(FeMn)Si向Al8(FeMn)2Si相的转变; 对合金进行轧制及最终热处理后, 结晶相碎化且沿轧向呈纤维状分布, 但结晶相的类型不变.     

Effect of Mg on microstructures and properties of Al-Mg-Si-Cu aluminium alloys for automotive body sheets

The effects of variation of Mg content on microstructures, the tensile properties and the formability of Al-Mg-Si-Cu alloys for automotive body sheets were investigated by means of scan electron microscopy, optical metallographic analysis, tensile and Ericsson tests. The results show that for Al-Mg-Si-Cu aluminium alloys with excessive Si, with an increment of Mg content, the strength enhances, the specific elongation and Erisson values of alloys decrease, and the number of Mg2 Si constituent increases and that of AI(MnFe)Si type constituents reduces. Al-Mg-Si-Cu aluminium alloys with excessive Si for automotive body sheets can present obviously the paint bake hardenability during the paint hake cycle (i. e. artificial aging at 170℃ for 30 min immediately after the solution treatment and quenching). Suitable Mg content should be controlled in the range of 0.8% and 1.2%(mass fraction).     

铝合金在海洋环境中的腐蚀研究（Ⅰ）：——海水潮汐区16年暴露试验总结

总结了铝合金在青岛海域海水潮汐区暴露16年的腐蚀试验结果，防锈铝LF2Y2、LF6M（BL）、F21M、180YS在海水潮汐区有好的耐蚀性，工业纯铝L4M、锻铝LD2CS的耐蚀性较差，硬铝LY11CZ（BL）、LY12CZ（BL）和超硬铝LC4CS（BL）的包铝层起着牺牲阳极作用，使基体受到保护，海生物污损对铝合金的腐蚀有明显影响，镁，锰能提高铝在海水潮汐区的耐蚀性，硅明显降低铝的耐蚀性，铜严重损害铝的耐蚀性。     

Al-0.66Mg-0.85Si合金均匀化过程中的组织演变(英文)

采用金相显微镜、扫描电子显微镜、透射电子显微镜和差示扫描量热法研究Al-0.66Mg-0.85Si合金在均匀化过程中的组织演变。合金铸态组织呈典型的枝晶形貌,存在α(Al)、Al15(FeMn)3Si2、Mg2Si,、Q(Al1.9CuMg4.1Si3.3)和Si相。铸态组织中存在2种不同晶体结构的Mg2Si相,一种是在铸造过程中形成的,另一种是在铸造完成后的空冷过程中形成的。经过545°C、20 h均匀化处理之后,组织中的Q、Mg2Si和Si相已完全溶入基体,残留的第二相主要是Al15(FeMn)3Si2相。Al15(FeMn)3Si2相的尺寸减小、球化并且在晶界上断续分布。在铸态和均匀化热处理状态中,均未发现含Zn相。     

Effect of Sr modification on microstructure and thermal conductivity of hypoeutectic Al−Si alloys

Trace amount of Sr (0.05 wt.%) was added into the hypoeutectic Al−Si (3−12 wt.% Si) alloys to modify their microstructure and improve thermal conductivity. The results showed that the thermal conductivity of hypoeutectic Al−Si alloys was improved by Sr modification, and the increment and increasing rate of the thermal conductivity gradually increased with Si content increasing. The improvement of thermal conductivity was primarily related to the morphology variation of eutectic Si phases. In Sr-modified Al−Si alloys, the morphology of eutectic Si phases was a mixed morphology of fiber structure and fine flaky structure, and the proportion of the fine flaky eutectic Si phases gradually decreased with Si content increasing. Under the Si content reaching 9 wt.%, the proportion of fine flaky eutectic Si phases was nearly negligible in Sr-modified alloys. Correspondingly, the increment and increasing rate of thermal conductivity of Sr-modified alloys reached the maximum and tended to be stable.     

铸态Mg-4Al-4Si合金的显微组织与力学性能

摘 要:采用重力铸造法制备Mg-4A1-4Si(AS44)镁合金,研究铸态合金的显微组织和室温力学性能.结果表明,铸态AS44合金主要由α-Mg基体、β-Mg17Al12相及Mg2Si相组成;Mg2Si粗大的呈树枝状、块状和汉字状3种形态;铸态合金的硬度为66.5 HV3,室温抗拉强度为108.8 MPa,屈服强度为72.3 MPa,伸长率为2.6％;拉伸断裂形式为准解理脆性断裂.     

Comparative evaluation of X‐ray test results with bend test results for aluminium alloy welded joints

The SiC particle reinforced aluminum alloy has been developed for various machine parts. Aluminum welded machine parts often require welded joints composed of dissimilar alloys. In the present study, electron beam weldability of dissimilar joints was investigated on different combinations of aluminum alloys of 10 mm thickness. The main alloy is 10% SiC particle reinforced Al–Si aluminum alloy. Combination wrought alloys are Al–Si, Al–Mg, Al–Mg–Si and Al–Zn–Mg–Cu alloys. The electron beam machine is a 6 kW high voltage type. The joint groove is of square butt without filler metal.

In the case of SiC reinforced alloy/Al–Si and Al–Mg, joints, weldability was poor because some weld imperfections were recognized such as arcing and other defects. In the case of SiC reinforced alloy/Al–Mg–Si, Al–Zn–Mg–Cu, the cracking sensitivity is low while some small porosity was recognized. Tensile strength became about 150 MPa such as SiC reinforced alloy. Impact values of the SiC reinforced alloy/Al–Mg–Si joint were recovered through 2160 h room temperature ageing. Micro segregation of the Si element was recognized for the SiC reinforced alloy/Al–Mg–Si joint by electron probe microanalyser analysis.     

Mg-5Sn-xSi合金的铸态显微组织和性能

根据4Mg+ SiO2=Mg2Si+2MgO,利用高纯度石英砂与Mg液反应,采用普通凝固方法制备Mg-Si二元中间合金.利用Mg-Si中间合金、99.9％Mg和99.9％Sn制备Mg-Sn-Si三元合金,通过调整Si的含量研究Mg-5Sn-xSi系合金的组织和性能.利用光学显微金相定量分析、XRD分析,以及显微硬度测试,研究添加0～10 ％Si铸态Mg-Sn-Si合金的显微组织与力学性能.实验结果表明,Mg-Sn-Si合金主要由α-Mg、Mg2 Sn和Mg2 Si 3相组成,无Mg-Sn-Si三元相.当Si≤6％时,合金显微硬度随Si含量的增加而增加.当Si含量≥6％时,合金显微硬度随Si含量的增加而降低.     

Effect of strontium on crystallization of Mg2Si phase in Al—Si—Mg casting alloys

Otical microscope and SEM were used to observe the changes of the microstructure of Al-11.6%Si-0.4% Mg alloys with varying strontium additions and the effect of strontium on the crystallization of Mg2Si phase was discussed.It is found that Mg2Si phase nucleastes on the the surfaces of the eutectic silicon flakes in the unfully modified alloys,growing as meshwork or bamboo-shoot shape,however,very few and fine Mg2Si particles phase are isolated at the boundaries of the eurectic cells in the fully modified alloys.Strontium has an important influence on the crystallization of Mg2Si phase in the Al-Si-Mg casting alloys and it is thought to be related to the increase of the amunt of dendritic αphase and the modifying degree of eutectic silicon phase.     

Al-Si合金中Si相的团粒化研究

利用金相和电子探针等手段研究了AC8C、ZL104和ZL109牌号的亚共晶及共晶Al-Si合金中共晶和初晶Si相的团粒化。结果表明，用Sr变质处理附以热处理手段相结合的方法可促使共晶Si相呈团粒状。并均匀分布干铝基体上，加入TiB2粒子可进一步促进共晶Si趋于圆滑，甚至使之团球化。使用杆状Al-P中间合金后，可使共晶Al-Si合金析出大量初晶Si，获得过共晶组织，并在一定条件下可促使初晶Si晶粒团粒化，提高活塞的金相等级。另外，在Si、Cu和Mg成分一定的条件下可形成一个球状复合相，为获得真正的球状Si相开辟了新思路。     

喷射成形过共晶Al-Si合金组织、性能的研究进展

过共晶Al-Si合金作为最具代表性的喷射成形材料在轻质、耐热、耐磨结构件,尤其是发动机缸套的工业化生产方面,已获得大量的应用。目前商用化的过共晶Al-Si合金在热稳定性和高温性能方面的不足已成为开发高性能发动机的限制因素,因而也成为近年来各研究机构的主要研究方向。用Fe,Mn,Cr为主的合金化代替传统的以Cu,Mg为主的合金化,使Al2Cu,Al2CuMg等强化相被稳定性更高的α—Al（Fe,TM）Si相所代替,达到了组织和室温、高温性能的双重优化,制备出继PEAK和OSPREY公司之后开发的可应用于更高性能发动机缸套部件的新型过共晶Al—Si合金。     

含Si量对Mullite纤维/Al-Cu-Si复合材料及其基体合金时效行为的影响

用挤压铸造方法制备了Mullite/Al Cu Si复合材料。用硬度 (HB)测试仪、差示扫描量热仪 (DSC)和显微镜研究含Si量变化和Mullite纤维对Al Cu Si合金时效硬化行为的影响 ;元素Si、Mullite纤维以及二者同时存在对Al Cu Si合金时效析出序列的影响。结果表明 :Si和Mullite纤维明显抑制了Al Cu合金GP区的形成 ;随着含Si量增加 ,Al Cu Si合金的时效硬化过程加快 ;Mullite纤维对Al Cu和Al Cu Si合金的时效硬化过程都具有加速作用 ,同时提高了基体合金的时效硬度 ,但相对而言 ,Mullite纤维对无Si的Al Cu合金的时效硬化加速作用更为明显一些。     

含Ca及Si镁合金的显微组织及力学性能

采用光学显微镜、扫描和透射电子显微镜研究了含Ca、 Si镁合金的显微组织特征. 铸态下, 仅含Ca的镁合金主要由镁基体和晶界离异共晶组织(Mg Mg2Ca)组成; 加入约0.5%(质量分数)Si后, 晶界离异共晶组织消失, 在晶界附近及晶内形成弥散分布的细小点状(球状)、针状和粗块状CaMgSi相; 当含Si量较高(约1.0%)时, 出现中国字形(针状)的Mg2Si相. 固溶时效后, 只含Ca的镁合金中晶界处离异共晶组织消失, 代之以长大了的颗粒状Mg2Ca相; 而Mg-Ca-Si合金的固溶时效组织较铸态无明显变化. 对合金常温和高温短时拉伸性能也作了初步探讨.     

添加Si对A_2B_7型电极合金结构及电化学贮氢性能的影响(英文)

为改善La–Mg–Ni系A2B7型合金的电化学贮氢性能,在合金中添加一定量的Si元素,通过真空熔炼及退火处理的方法制备La0.8Mg0.2Ni3.3Co0.2Six(x=0-0.2)电极合金。研究Si元素的添加对合金结构及电化学贮氢性能的影响。结果表明,铸态及退火态合金均为多相结构,分别为Ce2Ni7型的(La,Mg)2Ni7相和CaCu5型的LaNi5相以及少量的残余相LaNi3。Si元素的添加没有改变合金的主相,但使得合金中的(La,Mg)2Ni7相减少而LaNi5相增加。添加Si显著地影响了合金的电化学性能。随着Si含量的增加,铸态及退火态合金的放电容量逐步降低,但循环稳定性却随着Si含量的增加而增强。此外,合金电极的高倍率放电性能、极限电流密度、氢扩散系数以及电化学交流阻抗谱的测试均表明合金的电化学动力学性能随着Si含量的增加先增加而后减小。     

Evolution of eutectic structures in Al-Zn-Mg-Cu alloys during heat treatment

1 Introduction The solute redistribution during solidification leads to microsegregation and the formation of coarse intermetallic particles, which can significantly influence the properties and productivity of the 7000 series aluminium alloys[1]. In ord…     

MORPHOLOGY AND ORIENTATION CHARACTERISTICS OF DIRECTIONALLY SOLIDIFIED α(A1)-Mg_2Si EUTECTIC

ＭＯＲＰＨＯＬＯＧＹＡＮＤＯＲＩＥＮＴＡＴＩＯＮＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＯＦＤＩＲＥＣＴＩＯＮＡＬＬＹＳＯＬＩＤＩＦＩＥＤα（Ａ１）－Ｍｇ_２ＳｉＥＵＴＥＣＴＩＣ￥Ｓ．Ｐ．Ｌｉ；Ｓ．Ｘ．Ｚｈａｏ；Ｍ．ＸＰａｎ；Ｄ．Ｑ．Ｚｈａｏ；ａｎｄＸ．Ｃ．Ｃ?..     

Mechanical and thermo-physical properties of rapidly solidified Al−50Si−Cu(Mg) alloys for thermal management application

Al?high Si alloys were designed by the addition of Cu or Mg alloying elements to improve the mechanical properties. It is found that the addition of 1 wt.% Cu or 1 wt.% Mg as strengthening elements significantly improves the tensile strength by 27.2% and 24.5%, respectively. This phenomenon is attributed to the formation of uniformly dispersed fine particles (Al₂Cu and Mg₂Si secondary phases) in the Al matrix during hot press sintering of the rapidly solidified (gas atomization) powder. The thermal conductivity of the Al?50Si alloys is reduced with the addition of Cu or Mg, by only 7.3% and 6.8%, respectively. Therefore, the strength of the Al?50Si alloys is enhanced while maintaining their excellent thermo-physical properties by adding 1% Cu(Mg).     

均匀化退火对Mg-3Al-1Zn-2.2/5Sr镁合金中第二相的影响

为研究均匀化退火处理对Mg-3Al-1Zn-2.2/5Sr镁合金中第二相的影响,通过X射线衍射分析(XRD)、扫描电镜观察(SEM)和能谱分析(EDS)等手段,并结合Pandat热力学计算软件,对Mg-3Al-1Zn-2.2/5Sr镁合金均匀化退火后组织中的第二相的类型及形成原因进行了分析。结果表明:经过400℃,15 h(炉冷)的均匀化退火处理以后,合金铸态组织中原本存在的(Mg,Al)17Sr2相中固溶的Al元素所占原子分数有所降低。此外,Sr含量为2.2%(质量分数)的合金组织中可以观察到大量沿(Mg,Al)17Sr2相边缘分布的颗粒状Al4Sr相,而Sr含量为5%的合金中基本观察不到(Mg,Al)17Sr2相的变化。     

Microstructures and corrosion behaviors of Al–6.5Si–0.45Mg–xSc casting alloy

The microstructures and corrosion behaviors of the Al–6.5Si–0.45Mg casting alloys with the addition of Sc were investigated by using scanning electron microscopy, X-ray diffraction, electrochemical measurement techniques and immersion corrosion tests and compared with those of Sr-modified alloy. The results show that Sc has evident refining and modifying effects on the primary α(Al) and the eutectic Si phase of the alloy, and the effects can be enhanced with the increase of Sc content. When the Sc content is increased to 0.58 wt.%, its modifying effect on the eutectic Si is almost same as that of Sr. Sc can improve the corrosion resistance of the test alloy in NaCl solution when compared with Sr, but the excessively high Sc content cannot further increase the corrosion resistance of the alloy. The corrosion of the alloys mainly occurs in the eutectic region of the alloy, and mostly the eutectic α(Al) is dissolved. This confirms that Si phase is more noble than α(Al) phase, and the galvanic couplings can be formed between the eutectic Si and α(Al) phases.