预变形量对Fe-14.04Mn-0.22C合金阻尼性能的影响

通过对Fe-Mn基减振合金阻尼机制的研究，深入分析了预变形处理对Fe-14．04Mn-0．22C合金阻尼性能的影响。结果表明，该合金在预变形处理时，发生了γ→ε转变。预变形量在0-4％区间，随着预变形量增大，γ→ε转变生成的马氏体越多。在预变形量为4％时，合金的内耗达到最大值，随预变形量的进一步增大，阻尼性能开始下降。     

预变形对Fe-Mn合金层错几率和阻尼性能的影响

探讨了Fe-Mn合金的高阻尼机制并采用G-L位错脱钉模型对其进行描述,同时通过测定层错几率,揭示了预变形(0-10%)对Re-Mn合金阻尼性能影响的本质.采用倒扭摆测试合金的阻尼性能,SEM和TEM观察显微组织,XRD测定物相体积分数和层错几率.结果表明,Fe-Mn合金的高阻尼性能来源于层错界面上Shockley不全位错的脱钉运动,实验结果很好地符合G-L位错脱钉模型;预变形量小于4%时,预变形处理虽然对合金的ε马氏体量没有太大影响,但明显增加了其层错几率,即Shockley不全位错的数量,合金的阻尼性能随变形量增加逐渐提高;预变形量大于4%时,由于ε马氏体和层错的相互交割,增大了Shockley不全位错的脱钉难度,所以合金的阻尼性能随变形量增加逐渐下降.     

预变形对FeMnCr合金阻尼性能的影响

研究了不同的预变形量对FeMnCr合金阻尼性能的影响,并根据位错运动理论,分析了Shockley不全位错的运动对该合金阻尼性能的影响。研究采用倒扭摆测试合金阻尼性能,OLYMPUS显微镜分析合金的微观组织,XRD分析合金的相组成。结果表明,该合金的阻尼性能随应变振幅的变化规律符合Shockley不全位错脱钉运动模型;随着变形量的增加,Shockley不全位错密度增加,合金阻尼性能得到提高,在4%变形量时达到峰值;随着变形量的继续增大,虽然Shockley不全位错增加,但因全位错的分割作用,使其长度LN减小,造成阻尼性能下降。     

电脉冲处理对不同预变形量FeMnSiCrNiNbC合金记忆效应的影响

为进一步提高铁基形状记忆合金(SMAs)的记忆性能,研究了电脉冲处理对不同预变形量FeMnSiCrNiNbC合金形状记忆效应的影响.并对其微观机理进行初步探讨.结果表明,不同预变形量的Fel7Mn5Si8Cr5Ni0.5NbC合金经300V、1 Hz、13s电脉冲处理,形状恢复率(η)随预变形量的增加而增大,当预变形量为10%时获得最大η值(83%).SEM分析发现,随预变形量的增加,电脉冲处理诱导出NbC颗粒的数量更多、尺寸更小,进而有效改善合金的记忆性能.     

电脉冲处理对不同预变形量Fe17Mn5Si8Cr5Ni0.5NbC合金NbC析出相与形状记忆效应的影响(英文)

为进一步提高铁基形状记忆合金的记忆效应并改善处理技术,研究了电脉冲处理对不同预变形量Fe17Mn5Si8Cr5Ni0.5NbC合金性能的影响。结果表明:当预变形量低于 10%时,电脉冲处理后合金的形状回复率随着预变形量的增大而增大,且最大值比800 °C热处理的合金高 8%左右。与热处理状态相比,当预变形量低于10%时,随着预变形量的增大,电脉冲处理诱导出NbC颗粒的数量更多、尺寸更小、析出速度更快,进而有效改善合金的记忆性能。     

预拉伸变形量对2050铝锂合金组织和性能的影响

通过拉伸试验、晶间腐蚀试验以及透射电镜(TEM)等方法对固溶处理后不同预拉伸变形量处理并人工时效后2050铝锂合金厚板室温拉伸性能、抗晶间腐蚀性能以及合金的微观组织形貌进行了研究。结果表明,随预拉伸变形量的增加,合金L向和LT向的屈服强度和抗拉强度逐渐增大,变形量＞4.0%后趋于平稳,伸长率逐渐降低后趋于稳定;随预拉伸变形量增加,腐蚀形貌由晶间腐蚀变为点蚀,点蚀深度逐渐减小。预拉伸变形促进了人工时效过程中晶内T₁相的弥散析出,降低了晶界处T₁相含量,因此提高了合金的强度和抗晶间腐蚀性能。预拉伸变形量为5.0%时,合金的强度和抗晶间腐蚀性能最佳。     

固溶处理及预拉伸变形对2197铝锂合金组织与性能的影响

通过金相、扫描电镜、拉伸和断裂韧性试验等分析测试手段,研究了固溶处理温度及预拉伸变形量对2197铝锂合金板材组织和性能的影响。结果表明,2197铝锂合金在490～580℃温度范围内固溶再时效后,其强度随固溶处理温度的升高先增大后减小,强度峰值出现在540℃。当固溶处理温度高于565℃时,合金出现了再结晶现象。但是,合金在490～580℃固溶处理过程中均未出现明显的过烧现象。固溶处理后进行预拉伸变形可以有效提高合金的强度。综合考虑合金的强韧匹配,2197合金板材较优的固溶和预拉伸变形量分别为540℃×1.5 h和2%～5%。     

分步拉伸变形对TA15合金超塑性的影响

采用分步变形法对TA15合金在10 kN高温电子拉伸试验机上进行了超塑性拉伸试验,研究了变形温度和预变形量对该合金超塑性性能及微观组织演变。结果表明:变形温度为850~950℃和预变形量为100%~200%时,TA15合金呈现出良好的超塑性;变形温度为900℃和预变形量为150%时,该合金的超塑性能最好,最大延伸率为1456%;变形温度为950℃时,该合金的超塑性能降低,延伸率仅为188%。TA15合金的微观组织状态显示:该合金在拉伸变形过程中微观组织保持等轴状,但是随着变形温度的升高,晶粒开始长大,变形温度越高,晶粒长大越显著。     

Al-5%Fe合金轧制变形及组织性能研究

利用电磁铸造及固态挤压技术制备Al-5%Fe合金轧制坯锭,然后在不同工艺下进行轧制,研究该合金的轧制变形能力及合金的组织性能。研究发现:Al-5%Fe合金具有良好的高温轧制性能,合金在变形过程中随着变形量的增加富铁相被逐渐细化,对基体的割裂倾向相应减小;该合金经轧制后抗拉强度、伸长率随变形量的增大而增大,当变形量达到80%时,其室温下的抗拉强度和伸长率分别较电磁搅拌态的提高了52.5%和277%;该合金的断裂方式基本上是沿富铁相的穿晶断裂。     

含钪Al-Cu-Li合金的形变时效研究

通过显微组织观察和室温拉伸试验，研究了形变时效对含钪Al-Cu-Li合金组织和拉伸性能的影响。结果表明，时效前的预变形能促进T1(Al2CuLi)相弥散细小的析出，显著提高合金的强度，使时效峰值提前。合金的强度随预变形量的增大而升高，但预变形量过大，不利于T1相的析出形态和分布，影响合金的性能。在本试验条件下，该合金的最佳预变形量为3．5％。     

Microstructure and Tensile Behavior of Al8Co17Cr17Cu8Fe17Ni33 (at.%) High-Entropy Alloy

Microstructure evolution and tensile behavior of the high-entropy alloy Al₈Co₁₇Cr₁₇Cu₈Fe₁₇Ni₃₃ (at.%) are investigated at room temperature and at 500°C in the as-cast state and under different heat-treatment conditions. Detailed microstructural characterizations are carried out using optical microscopy, scanning electron microscopy, and transmission electron microscopy. The equilibrium phase evolution as a function of temperature was calculated using the Thermo-Calc software (Thermo-Calc Software, Stockholm, Sweden) integrated with TTNi-7 database. The observed majority phase is a face-centered cubic solid solution for all tested specimens. Tensile ductility at room temperature and at elevated temperature is enhanced by heat treatment at 1150°C. An embrittlement phenomenon has been observed after a heat treatment at 700°C resulting in significant degradation in tensile properties.     

Gr.17钛钯合金性能影响因素分析

文章研究了杂质元素Fe、O含量及其热处理工艺和显微组织对Gr.17钛钯合金力学性能的影响。结果表明,杂质元素Fe、O含量是板材力学性能的主要影响因素,应对其严格控制。均匀细小的等轴α组织可使Gr.17钛钯合金获得良好的综合机械性能。在680~740℃之间退火,可使板材获得较好的塑性与强度的匹配。通过此研究,使板材屈服强度σ0.2明显降低,塑性与强度均达到了标准的要求。     

Tribological behaviour of HVOF sprayed near-nanostructured and microstructured WC-17wt.%Co coatings

A ‘duplex cobalt coated’ near-nanostructured WC-17wt.%Co powder was used to produce nanostructured coatings. The tribological performance of this coating was compared with a commercial WC-17wt.%Co microstructured coating using a pin-on-plate method (ASTM G133-05 standard) with a data acquisition software to perform a real time analysis of the sliding wear process. The wear rate was studied using loads from 10 to 60 N and for various sliding distances. The metallurgical analysis of the coatings showed that the duplex Co coated powder could be sprayed to produce dense coating. Furthermore, the near-nanostructured coating showed better fracture toughness values and this corresponded to a difference in wear mechanism between the two types of coatings. The greater “plasticity” in the near-nanostructured coating was recorded as microgrooves in the wear tracks and, in comparison, brittle fracture was observed in the wear tracks produced on the microstructured coating.     

Comparison of the Isothermal Oxidation Behavior of As-Cast Cu–17%Cr and Cu–17%Cr–5%Al. Part II: Scale Microstructures

The isothermal oxidation kinetics of as-cast Cu–17%Cr and Cu–17%Cr–5%Al in air were studied between 773 and 1,173 K under atmospheric pressure. Details of the oxidation kinetics of these alloys were discussed in Part I. This paper analyzes the microstructures of the scale and its composition in an attempt to elucidate the oxidation mechanisms in these alloys. The scales formed on Cu–17%Cr specimens oxidized between 773 and 973 K consisted of external CuO and subsurface Cu₂O layers. The total thickness of these scales varied from about 10 μm at 773 K to about 450 μm at 973 K. In contrast, thin scales formed on Cu–17%Cr–5%Al alloys oxidized between 773 and 1,173 K. The exact nature of these scales could not be determined by X-ray diffraction but energy dispersive spectroscopy analyses were used to construct a scale composition map. Phenomenological oxidation mechanisms are proposed for the two alloys.     

17th IFHTSE Congress

Abstract

The 17th IFHTSE Congress will be the first to be held in Japan since the Kyoto meeting in 1992. This timing is particularly appropriate in commemorating the fiftieth anniversary of the founding of the Japan Society for Heat Treatment (JSHT). The Congress is scheduled to be held at the Kobe Convention Centre, Hyogo, on 27–30 October 2008.     

PQF的17年

PQF轧管机是迄今工艺技术最为先进的连轧管机。限动芯棒连轧管机自发明以来,经历了二辊式连轧管工艺（MPM）和三辊式连轧管工艺（PQF）两大发展时段。PQF轧管机改进了传统的MPM工艺,其换辊方式也由轴向换辊（ACO）发展为侧向换辊（LCO）。介绍了PQF轧管机的发展历程和设备构成特点。     

TA17合金简介

介绍了TA17合金的标准及性能。该合金具有中等强度,良好的焊接性能,抗水腐蚀性能和ECP性能。它适合在造船、化工、航空和核工业等领域推广应用。