Cu的时效行为及其对0Cr14Ni5Mo2Cu2Nb钢性能的影响

研究了不同时效温度下的沉淀硬化不锈钢0Cr14Ni5Mo2Cu2Nb的TEM组织、硬度和冲击韧性.结果表明时效过程中,0Cr14Ni5Mo2Cu2N钢主要以ε-Cu相析出为主.时效温度为420℃时,Cu以细小共格ε-Cu相析出,导致0Cr14Ni5Mo2Cu2N钢的硬度达到峰值,而韧性最差,冲击断口以解理为主.随着时效温度增加,ε-Cu相逐步脱溶长大,基体再结晶,硬化程度逐步降低,韧性升高,冲击断口逐步过渡为全韧窝形貌.0Cr14Ni5Mo2Cu2Nb钢的韧性主要决定于冲击裂纹扩展功.时效组织对0Cr14Ni5Mo2Cu2Nb钢冲击裂纹形成功影响较小,对裂纹扩展功有着较大影响.     

超低碳含铜微合金钢中时效析出相的晶体结构

用高分辨电子显微镜(HREM)进行了Nb、Cr、Mo、Ni等微合金元素复合微合金化的实用超低碳含Cu钢中时效析出相的形貌观察及晶体结构鉴定,探索将HREM分析技术有效应用于工程材料微观结构研究的新途径.在300万倍以上的放大倍率下清晰观察到了尺寸仅有十个nm左右的细小弥散分布的时效析出颗粒以及其中的孪晶结构,还有大量在局部微区形成的过渡结构.尝试用单个颗粒HREM像上的晶格条纹间距鉴定了钢中除ε-Cu以外的另3类时效析出相的晶体结构.结果表明,时效期间钢中析出Cu、Nb、Cr、Mo、Ni的特殊碳化物(碳氮化物),与ε-Cu共同产生时效强化作用.提出了用HREM像对实用钢材中弥散分布的微细析出相进行晶体结构鉴定的实验方法.     

高韧性不锈钢FV520(B)的析出硬化行为研究

研究了350、420、470、520、560、600、630℃时效温度下沉淀硬化不锈钢FV520(B)的TEM组织、硬度和示波冲击韧度。结果表明:时效过程中,FV520(B)钢主要以富铜相-εCu析出为主。硬度在420℃时效出现峰值,而韧性最差,主要与组织中细小富铜相共格析出有关。随着时效温度增加,富铜相逐步脱溶长大,基体再结晶,硬化程度逐步降低。FV520(B)钢的韧性主要决定于冲击裂纹扩展功。时效组织对FV520(B)钢冲击裂纹萌生功影响较小,对裂纹扩展功有着较大的影响。     

时效处理对0Cr17Ni4Cu4Nb马氏体沉淀硬化不锈钢组织与性能的影响

研究了时效处理对0Cr17Ni4Cu4Nb马氏体沉淀硬化不锈钢组织和性能的影响。结果表明:0Cr17Ni4Cu4Nb钢时效温度的升高,强度、硬度呈先升后降趋势,460℃时效,强度达到峰值,伸长率变化不大,而面缩率有比较明显的先降后升的趋势,冲击值随时效温度的升高而提高,并且高于525℃时效冲击值陡然提高;随时效温度的升高,强化相析出增加并有长大趋势,525℃时效发生聚集长大,610℃时效可观察到析出物堆积;时效时间对0Cr17Ni4Cu4Nb不锈钢的组织、性能影响不大。     

时效温度对2Cr16Ni2MoN钢组织与性能的影响

采用金相显微镜、透射电镜和扫描电镜观察及力学性能的测试,研究了时效温度对2Cr16Ni2MoN钢组织与性能的影响.结果表明,2Cr16Ni2MoN钢时效硬化的主要原因是在板条马氏体上析出与基体共格的(Cr,Fe,Mo)2C碳化物,该钢在560℃时效时可以获得较高的强度与冲击韧度.     

时效对0Cr15Ni5Cu2Ti钢组织与性能的影响

研究了960℃℃和1000℃固溶处理后，时效对马氏体沉淀硬化不锈钢0Cr15Ni5Cu2Ti微观组织与力学性能影响。结果表明，采用960℃和1000℃固溶处理，在455～460℃时效冲击值出现最低值，断121表现为准解理；强度和硬度在460℃时效出现峰值。主要与组织中细小富铜相共格析出有关。随着时效温度增加，钢中富铜相长大，强度和硬度也随之降低。     

三维原子探针对10Ni3MnCuAl钢中NiAl和Cu析出位置关系的研究

将析出硬化钢10Ni3MnCuAl在900℃固溶处理2 h,500℃时效处理4 h或100 h后,用三维原子探针(3DAP)研究钢中NiAl和Cu的析出位置关系。结果表明,固溶样品中Ni、Al和Cu三种元素分布均匀。500℃时效4 h的样品中发现金属间化合物NiAl和富Cu相在相同位置析出,随着时效时间增加到100 h,NiAl相和富Cu相有逐渐分离的趋势,这是因为NiAl相为体心立方的B2结构,而富Cu相此时已趋于向面心立方的ε-Cu转变。     

时效对FV520(B)钢组织和性能的影响

采用透射电镜观察、示波冲击试验、硬度试验等方法,研究了经850 ℃中间调整处理后,不同时效温度对FV520(B)沉淀硬化不锈钢的组织和性能的影响.结果表明,在420℃时效,硬度出现峰值,主要与组织中细小的富铜相共格析出有关.随着时效温度提高,富铜相逐步脱溶长大、基体再结晶,硬度逐步降低.FV520(B)钢的冲击总功主要决定于裂纹扩展功,时效组织对FV520(B)钢冲击裂纹萌生功影响较小,对裂纹扩展功有着较大的影响.420℃及470℃时效状态下的冲击试样扩展区断口以解理形貌为主,而其它时效状态下为韧窝形貌,但韧窝细节各不相同.     

时效温度对17-4PH沉淀硬化不锈钢析出行为和硬化效果的影响

研究了17-4PH沉淀硬化不锈钢在(480~630)℃×4 h时效处理中的析出行为和硬化效果。结果表明,ε-Cu相析出使17-4PH马氏体沉淀硬化不锈钢硬化,硬化效果与Cu的析出和位错密度的变化密切相关。时效温度和基体组织对Cu析出行为有很大影响。时效温度越高,ε-Cu相颗粒的尺寸越大,形态由颗粒状最终变为短棒状。在位错密度低的区域,ε-Cu相颗粒的长大倾向要比位错密度高的区域大。     

时效温度对HSLA100钢组织与性能的影响

研究了HSLA100钢轧态及时效过程中组织与力学性能的变化.结果表明:HSLA100钢轧态组织为高密度位错的板条贝氏体,板条间分布着少量M-A岛.经450℃时效处理后,大量球状ε-Cu相沉淀析出,此时钢板屈服和抗拉强度最高,而-40℃冲击功最低.在450～720℃时效时,随时效温度升高,高密度板条贝氏体发生回复,ε-Cu相粗化成短棒状,屈服强度连续下降,但在650℃时效时仍达到760 MPa的较高水平;抗拉强度在650℃时达到最低值后小幅上升:-40℃冲击功持续升高至700℃附近达到峰值.钢质纯净度是影响HSLA100钢低温韧性的一个主要因素,虽然通过升高时效温度可在一定程度上提高钢的低温冲击韧度,但增幅有限.     

Al2O3/Cu复合材料制备中的Cu2O-Al体系化学反应

对Cu2O与Al进行热力学分析后将其粉末压制成块,测试了不同温度下反应的热分析曲线,并对反应后的试样进行X射线衍射分析.结果表明Cu2O-Al体系化学反应包括3个阶段,即第1阶段体系温度T＜910 K,有少量Al2O3和Cu生成;第2阶段体系温度为910 K≤T＜1103 K,Cu2O-Al体系未发生化学反应;第3阶段体系温度为1103 K≤T≤1373 K,Cu2O-Al体系发生化学反应,其产物为Cu、Al2O3及CuAlO2.     

Quasi-ternary System Cu2Te-CdTe-In2Te3

Phase equilibria in the quasi-ternary system Cu₂Te-CdTe-In₂Te₃ were investigated by differential thermal and x-ray phase analyses methods. Five vertical sections CuInTe₂-CdTe, ‘Cu_1.5In_0.5Te_1.5’-CdTe, CuInTe₂-CdIn₂Te_4, CuIn₅Te₈-CdTe, CuIn₅Te₈-CdIn₂Te₄ were constructed. System triangulation was performed, and the boundaries of six single-phase fields at 670 K were determined, which are the solid solution ranges of the components and the intermediate phases of the system. Liquidus surface projection was investigated, and we have identified a monovariant eutectic process L ? β + δ, and three nonvariant processes L_U + η ? δ + ε, β + δ ? α + ζ, δ ? γ + ε + η at 965 K, 847 and 690 K, respectively, that take place in the system.     

The effect of Cu addition on the thermoelectric properties of Cu2CdGeSe4

Recently, research in copper based quaternary chalcogenide materials has focused on the study of thermoelectric properties due to the complexity in the crystal structure. In the present work, stoichiometric quaternary chalcogenide compounds Cu_2+xCd_1−xGeSe₄ (x = 0, 0.025, 0.05, 0.075, 0.1, 0.125) were prepared by solid state synthesis. The powder X-ray diffraction patterns of all the samples showed a tetragonal crystal structure with the space group I-42m of the main phase, whereas the samples with x = 0 and x = 0.025 revealed the presence of an orthorhombic phase in addition to the main phase as confirmed by Rietveld analysis. The elemental composition of all the samples characterized by Electron Probe Micro Analyzer showed a slight deviation from the nominal composition. The transport properties were measured in the temperature range of 300 K–723 K. The electrical conductivity of all the samples increased with increasing Cu content due to the enhancement of the hole concentration caused by the substitution of Cd (divalent) by Cu (monovalent). The positive Seebeck coefficient of all the samples in the entire temperature ranges indicates that holes are the majority carriers. The Seebeck coefficient of all the samples decreased with increasing Cu content and showed a reverse trend to the electrical conductivity. The total thermal conductivity of all the samples decreased with increasing temperature which was dominated by the lattice contribution. The maximum figure of merit ZT = 0.42 at 723 K was obtained for the compound Cu_2.1Cd_0.9GeSe₄.     

KINETICS OF INTERACTION BETWEEN Cu_2S AND Cu_2O IN SOLID STATE UNDER NONISOTHERMAL CONDITION

ＫＩＮＥＴＩＣＳＯＦＩＮＴＥＲＡＣＴＩＯＮＢＥＴＷＥＥＮＣｕ２ＳＡＮＤＣｕ２ＯＩＮＳＯＬＩＤＳＴＡＴＥＵＮＤＥＲＮＯＮＩＳＯＴＨＥＲＭＡＬＣＯＮＤＩＴＩＯＮ①ＳｏｎｇＮｉｎｇ，ＬｉｕＣｈｕｎｐｅｎｇＤｅｐａｒｔｍｅｎｔｏｆＭｅｔａｌｕｒｇｙ，Ｋｕｎｍ...     

The Quasi-Ternary System Cu2Se-Ga2Se3-GeSe2

The quasi-ternary system Cu₂Se-Ga₂Se₃-GeSe₂ was investigated using the methods of differential thermal and x-ray analysis. An isothermal section at 770 K and a liquidus surface projection of the phase diagram were constructed. The existence of the quaternary phase CuGaGeSe₄, the boundaries of solid solutions ranges of the system compounds were established.     

电铸制备TiB_2/Cu复合材料的性能

使用粒度约为3μm的导电陶瓷TiB_2颗粒作为铜基复合材料的增强相,在酸性硫酸铜溶液中用电铸方法制备TiB_2/Cu电火花加工用工具电极。用扫描电镜和金相显微镜观察其组织结构,用维氏硬度计测量硬度,用中性盐雾试验测量其耐腐蚀性,用电火花加工脆硬材料衡量其抗电蚀性。结果表明:电铸Cu与TiB_2/Cu晶粒平均直径分别为30,10μm,硬度分别为984,1235 MPa,腐蚀失重分别为47.8,40.3 mg;TiB_2颗粒的加入可显著细化晶粒,提高硬度、耐腐蚀性和抗电蚀性。     

Structure stability of Ti3AlC2 in Cu and microstructure evolution of Cu–Ti3AlC2 composites

The structural stability of Ti₃AlC₂ in Cu and the microstructure evolution of Cu–Ti₃AlC₂ composites prepared at different temperatures were investigated by high-resolution transmission electron microscopy and X-ray diffraction. A mild reaction between Ti₃AlC₂ and Cu occurred at 850–950 °C, and strong reactions occurred above 950 °C. The reaction was identified as diffusion of Al from Ti₃AlC₂ into Cu to form Cu(Al) solid solution. Ti₃AlC₂ retained its structure under the partial loss of Al. Further depletion of Al resulted in highly defective Ti₃AlC₂ accompanied by the inner diffusion of Cu into Ti₃AlC₂ along the passway left by the Al vacancies. When Al was removed, Ti₃AlC₂ decomposed and transformed into cubic TiC_x. In addition, TiC twins formed by the aggregation of C vacancies at twin boundaries. With the help of first-principles calculation and image simulation, an ordered hexagonal TiC_x was identified as a transition phase linking Ti₃AlC₂ and c-TiC_x. The effect of the reaction and phase transformation on the microstructure and properties of Cu–Ti₃AlC₂ composites was also discussed.     

Ti_2SiC_2/Cu纳米复合材料的制备与微观组织

研究了用微米级Ti2SiC2陶瓷与Cu制备纳米复合材料的工艺过程。分别选用钢球和玛瑙球进行球磨,对Ti2SiC2颗粒的细化和在Cu中分散性的影响进行了研究。结果表明,在其它实验参数相同的情况下,用两种不同材质的磨球所获得的混合粉形态有很大差异,用玛瑙磨球可以更好地使Ti2SiC2颗粒细化并均匀分散在Cu基体中,而用钢球则易产生混合粉的团聚。另外,随着球磨时间的延长,Ti2SiC2先后经历了颗粒细化、均匀镶嵌在基体中两个阶段。对球磨后的混合粉在850℃及20MPa的压力下成功地制备了组织成分均匀的大块纳米复合材料,其力学性能与同成分的普通复合材料相比有明显提高。     

Ti2SiC2/Cu纳米复合材料的制备与微观组织

研究了用微米级Ti2SiC2陶瓷与Cu制备纳米复合材料的工艺过程。分别选用钢球和玛瑙球进行球磨，对Ti2SiC2颗粒的细化和在Cu中分散性的影响进行了研究。结果表明，在其它实验参数相同的情况下，用两种不同材质的磨球所获得的混合粉形态有很大差异，用玛瑙磨球可以更好地使Ti2SiC2颗粒细化并均匀分散在Cu基体中，而用钢球则易产生混合粉的团聚。另外，随着球磨时间的延长，Ti2SiC2先后经历了颗粒细化、均匀镶嵌在基体中两个阶段。对球磨后的混合粉在850℃及20MPa的压力下成功地制备了组织成分均匀的大块纳米复合材料，其力学性能与同成分的普通复合材料相比有明显提高。