机械合金化Cu－5Cr合金的组织性能研究

研究了机械合金化制粉、热静液挤压致密制备的Ｃｕ－５Ｃｒ合金的组织与性能。机械合金化Ｃｕ－５Ｃｒ合金由于细晶强化和弥散强化的作用，具有很高的强度（σｂ≥７５０ＭＰａ），经热处理后，合金具有较高的延伸率（δ≥８％）和导电性（≥６０％ＩＡＣＳ）。材料晶粒达到０．１μｍ级，析出的Ｃｒ粒子达到纳米级。     

机械合金化Cu—5Cr合金的组织性能研究

研究了机械化金化制粉，热静液挤压致密制备的Ｃｕ－５Ｃｒ合金的组织与性能，机械合金化Ｃｕ－５Ｃｒ合金由于细晶强化和弥散强化的作用，具有很高的强度（σｂ≥７５０ＭＰａ）经热处理后，合金具有较高的延伸率（δ≥８％）和导电性（≥６０％ＩＡＣＳ）。材料晶粒达到０．１μｍ级，析出的Ｃｒ粒子的达到纳米级。     

铁锰硅铬镍形状记忆合金的性能

研究了化学成分及训练对铁锰硅铬镍合金形状记忆效应的影响，并测试了合金的抗蠕变性能和耐腐蚀性能。结果表明，Ｆｅ１４Ｍｎ６Ｓｉ９Ｃｒ５Ｎｉ合金具有较好的形状记忆效应以及较好的抗蠕变性能、耐碱性腐蚀性能和耐晶间腐蚀性能。训练可提高相对应变回复率３０％～５０％（在εＰ＝４％～９％）。绝对应变回复率可达６２％。     

微晶,纳米晶CuCr触头材料的组织及性能

采用机械合金化的方法制备出Ｃｕ－Ｃｒ纳米合金粉并分别在９２０℃，７５０℃及５８０℃将合金粉热压烧结得到微晶，纳米晶ＣｕＣｒ合金。５８０℃热压可以得到致密度大于９０％的钠米晶ＣｕＣｒ块体，７５０℃及９２０℃热压晶粒长大到微米量级。     

微合金元素Cr高碳钢组织性能研究

研究了微合金元素Ｃｒ对高碳钢组织性能的影响以及Ｃｒ元素合理入量,结果表明,微合金元素Ｃｒ的加入优化了材料的组织构成,减少了组织中先共析铁素体含量,增加了素氏体含量,使线材抗拉强度增加８０～１００ＭＰａ,综合性能得到提高,Ｃｒ元素合理加入量应控制在０．１８％～０．２４％范围内。     

SHS-离心法制备的Fe-Cr-Ni耐蚀合金的显微组织及力学性能

ＳＨＳ（ＳｅｌｆｐｒｏｐａｇａｔｉｎｇＨｉｇｈｔｅｍｐｅｒａｔｕｒｅＳｙｎｔｈｅｓｉｓ）离心法具有高温、快速、反应过程复杂等特点，因而其产物的组织和性能也具有它的独特性。本文研究了ＳＨＳ离心法制备的ＦｅＣｒＮｉ耐蚀合金的显微组织及力学性能。     

Cu—C—Ti系和Cu—CuO—Al系合金粉末的机构合金化

将Ｃｕ－Ｃ３．３％－Ｔｉ１３．３％和Ｃｕ－ＣｕＯ２．５％－Ａｌ１．１％二合金粉末分别进行机械合金化，结果发现，经２０ｈ球磨后，Ｃ的衍射峰已经消失，Ｔｉ，Ａｌ，ＣｕＯ的衍射峰强度显著降低；６０ｈ球磨后，二合金粉末都形成了Ｃｕ基过饱和固溶体；１００ｈ球磨后，部分Ｔｉ，Ｃ，Ａｌ，Ｏ溶质元素脱溶析出，并反应生成ＴｉＣ和Ａｌ２Ｏ３。     

TiAl基合金显微组织与室温断裂韧性关系的研究

分别测试了具有不同显微组织的Ｔｉ３３Ａｌ３Ｃｒ０．５Ｍｏ（ｗｔ％）合金的室温断裂韧性，发现在晶粒尺寸相当的条件下，全层片组织合金试样的断裂韧性最高，双态组织最低。这主要归因于全层片组织能够较好地调节应变不协调性，从而使断裂应变提高，塑性区扩大     

SMRI—92型D墨铸铁玻璃模具的性能研究

本试验研究了玻璃模具用Ｄ墨铸铁的墨微组织及耐热性能。结果表明，试样断口呈银灰色，晶粒细小而致密，石墨形态为Ｄ形石墨，基体组织为细片状珠光体（〉９０％）；Ｄ墨铸铁的抗氧化、抗生长及热疲劳抗力等综合性能良好。工业性试验表明，该玻璃模具具有抗氧化、耐磨损、易修复、使用寿命长等特点，其热循环次数达７０万次，使用寿命比ＣｒＭｏＣｕ材料提高３．５倍。     

挤压用的新型铝──锂合金

挤压用的新型铝──锂合金据世界专利９４２４３２９号报道，加拿大铝业公司国际有限公司（ＡｌｃａｎＩｎｔｅｒｎａｔｉｏｎａｌＬｔａ）发明一种供航天航空工业用的铝－锂合金，具有相当好的挤压性能，可用于挤压各种型材。它至少含有０．１％Ｃｕ和≥１．５％Ｌｉ；铸...     

Tribological and Mechanical Properties of Al(Cu)/MWCNT Nanocomposite Prepared by Mechanical Alloying and Hot Extrusion

The bulk Al–Cu-multiwall carbon nanotube (MWCNT) nanocomposite was prepared using mechanical alloying (MA) and hot extrusion processes. Al–4 wt % Cu powder mixture was first milled for 20 h to form the nanostructured Al(Cu) solid solution. The MWCNT was then added to the Al(Cu) powder mixture and further milled for 5 h. X-Ray Diffraction (XRD) and Differential Thermal Analysis (DTA) were performed to study the phase transformations during mechanical alloying and hot extrusion. Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) were also employed to study the samples microstructure. Mechanical properties of the bulk Al(Cu)/CNT nanocomposite were also studied using room and high temperature compression and wear tests. The results showed that after 20 h of mechanical alloying, a supersaturated Al(Cu) solid solution with the average grain size of 25 nm was achieved. Homogenous distribution of CNTs in the Al(Cu) supersaturated matrix was obtained. CNTs retained their tubular structure after 5 h milling time. Hot extrusion process at 550°C also led to the formation of bulk samples with nearly full density. The average yield and compressive strength of the Al(Cu)/CNT nanocomposite were found to be around 450 and 590 MPa at room temperature. The bulk nanocomposite showed suitable thermal stability by keeping its strength up to 300°C.     

机械合金化制备铜碳合金增强铜-石墨复合材料

通过机械合金化制备Cu-5 ％C合金粉,并采用粉末冶金工艺制备铜碳合金增强铜-石墨复合材料即Cu-(Cu-5％C)-C,研究了制粉工艺和Cu-5％C合金粉对该复合材料显微组织及物理性能的影响.结果表明:随着球磨时间的增加,合金粉中铜的晶格常数先增大后减小,衍射峰强度不断降低,半高宽逐渐增大;球磨40 h后合金粉中的石墨衍射峰消失,再经400℃退火3h则球磨产生的次生相Cu2O衍射峰消失,且石墨峰未复现.当石墨含量为4％,合金碳含量不超过1.5％时,Cu-(Cu-5 ％C)-C复合材料试样的电导率均达61％ IACS以上;当合金碳含量为1.0％时,复合材料的屈服强度显著提高;当合金碳含量达到1.5％时,复合材料中的合金相严重分解,其增强效果大为减弱.     

机械合金化制备SiC弥散强化铜基复合材料

用机械合金化(MA)制备了一种以SiC为增强相的Cu／sic复合材料,研究了机械合金化过程中SIC颗粒形貌、尺寸的变化,以及增强相的含量对复合材料抗拉强度、硬度、相对电导率及显微结构的影响。结果表明,Sic对于铜是一种有效的增强相,当SiC的质量百分含量为1％时,强化效果较佳,抗拉强度可达391MPa,相对电导率为50．2％,性能较优。     

Structure and properties of rapidly solidified 7075 P/M aluminum alloy modified with nickel and zirconium

Aluminum alloy 7075 was modified by additions of 1.1 wt pct nickel and 0.8 wt pct zirconium, rapidly solidified by ultrasonic gas atomization, canned, cold compacted, hot extruded, and evaluated in terms of structure and properties. Significant improvements in tensile strength (627 MPa YS and 680 MPa UTS) and crack growth rates were realized, along with a decrease in fracture toughness (23.7 MPa√m) while maintaining ductility (10 pct elong.) as compared to nominal I/M 7075 behavior. The stress for 10⁷ cycles fatigue life was greater than 275 MPa, which represents a 73 pct increase over that of I/M 7075. A variety of experiments was performed to evaluate effects on strength, ductility, and on structure. The variables were: powder size distribution, extrusion ratio, extrusion profile, different size fractions from the same lot of powder, and different locations of test bars in the several extrusions. Tensile properties, toughness, and fatigue properties were not importantly influenced by the location of test bars in the cross section or length of rectangular extruded bars. A comparison of mechanical properties from extruded bars prepared from ?53 μm powdersvs 53 to 250 μm powders showed a small loss of ductility and fatigue stress for 10⁷ cycles for the fine powder product. Higher extrusion ratios were beneficial for mechanical properties.     

Hot Extrusion of Nanostructured Al-Powder Alloys: Grain Growth Control and the Effect of Process Parameters on Their Microstructure and Mechanical Properties

Two nanostructured aluminum powder alloys (supersaturated Al4.5Cu prepared by mechanical alloying, and Al3.0Fe0.42Cu0.37Mn rich in precipitates and prepared by rapid solidification via gas atomization) were consolidated into bulk material under various processing conditions via hot extrusion. The microstructural modifications and mechanical properties of the consolidated alloys as a function of the extrusion conditions were investigated and are discussed here. The effect of pre-existing precipitates from nonsupersaturated alloy is shown to be more effective for controlling grain growth during consolidation. The increase in the extrusion load, with a concomitant increase in the extrusion rate and decrease in temperature, is shown to lead to microstructural modifications. The differences in mechanical properties measured by compressive tests are also discussed in association with the extrusion parameters. Furthermore, suggestions are given for rationalizing the extrusion rate and temperature for the consolidation of nanostructured aluminum powder alloys via hot extrusion.     

机械合金化制备Fe-Co系非晶合金

在高纯氩气保护下采用高能球磨法对原子组成为Fe44Co44Zr3.5Nb3.5B4Cu1的混合粉末进行机械合金化(MA)实验,成功地制取了非晶合金粉末.利用X射线衍射(XRD)、扫描电镜(SEM)、差热分析(DTA)对其进行测试,结果表明:Fe-Co系的混合粉末在MA过程中,通过原子之间的相互固溶、扩散可形成非晶态.此非晶合金的形成是晶粒细化、球磨过程中的缺陷、应力和致密堆垛结构等多种因素综合作用的结果,这与机械合金化的合成机理之一的扩散型机制相吻合.用非晶化的热力学条件判据和动力学条件判据对此合金进行计算,其结果也表明此合金已非晶化.     

挤压致密超细WC/纳米Al2O3弥散强化铜基复合材料的组织性能研究

以纳米Al₂O₃颗粒、超细WC粉末、工业纯Cu粉末为原料, 通过热挤压致密获得了超细WC/纳米Al₂O₃弥散强化铜基(WC-Al₂O₃/Cu)复合材料, 研究了挤压态WC-Al₂O₃/Cu复合材料的微观组织及力学性能。结果表明: 成分为5% WC-2% Al₂O₃/Cu和10% WC-2% Al₂O₃/Cu (质量分数)的两种原料粉末, 经机械球磨、冷压、真空烧结和热挤压后, 其相对密度均达到了99%以上, 超细WC和纳米Al₂O₃强化相颗粒呈均匀弥散分布, 具有很好的导电性及力学性能; 其中, 5% WC-2% Al₂O₃/Cu复合材料的综合性能更佳, 其抗拉强度达到235.06 MPa, 延伸率为15.47%, 导电率可达85.28% IACS, 软化温度不低于900℃。     

碳纳米管对W-Cu复合材料致密度和硬度的影响

采用机械合金化技术并结合真空烧结制备W-20％Cu／C复合材料,利用碳纳米管具有良好的综合性能作为W-20％Cu复合材料的强化相．采用粒度测试仪分析碳纳米管添加量不同时的W-20％Cu复合粉末粒径并测试W-20％Cu／C烧结体的密度和硬度,分析碳纳米管添加对W-20％Cu复合粉末粒度及W-20％Cu复合材料密度和硬度的影响．研究结果表明：添加碳纳米管可不断细化W-20％Cu复合粉末晶粒,W-20％Cu复合材料的密度和硬度随着碳纳米管质量分数的增加而逐渐提高,说明采用机械合金化技术能够使碳纳米管弥散分布在W-20％Cu复合材料中,充分发挥细晶强化作用．     

粉末冶金铜铁合金的组织与性能

分别以元素混合粉、机械合金化粉和水气联合雾化合金粉为原料,结合冷等静压成形、烧结及轧制工艺制备了Cu?5％Fe合金(质量分数),对比了三种原料粉的铜铁合金粉末形貌、微观组织、力学性能及物理性能.结果表明,铁颗粒分布均匀,元素混合、机械合金化和水气联合雾化法粉末烧结体中铁颗粒平均尺寸分别为9.4μm、1.2μm、3.5μ...     

碳纳米管对W-Cu 复合材料致密度和硬度的影响

采用机械合金化技术并结合真空烧结制备W-20 %Cu/C 复合材料,利用碳纳米管具有良好的综合性能作为W-20 %Cu 复合材料的强化相. 采用粒度测试仪分析碳纳米管添加量不同时的W-20 %Cu 复合粉末粒径并测试W-20 %Cu/C 烧结体的密度和硬度, 分析碳纳米管添加对W-20 %Cu复合粉末粒度及W-20 %Cu 复合材料密度和硬度的影响.研究结果表明:添加碳纳米管可不断细化W-20 %Cu 复合粉末晶粒,W-20 %Cu 复合材料的密度和硬度随着碳纳米管质量分数的增加而逐渐提高,说明采用机械合金化技术能够使碳纳米管弥散分布在W-20 %Cu 复合材料中,充分发挥细晶强化作用.