热处理工艺对TA17合金棒材组织的影响

研究了热处理对TA17合金φ10mm棒材组织的影响,并对该合金显微组织的类型及特征进行了综合评价,目的是为制定加工工艺等提供参数.结果表明,当加热温度在相变点以下,TA17合金棒材的组织形貌特征是等轴α 晶间B组织、变形的等轴α 晶间β组织或二者的混合组织.随着温度的升高晶粒呈长大趋势,此时保温时间、冷却方式对组织形貌影响不大.加热温度接近相变点时,TA17合金棒材的组织形貌特征是粗晶粒等轴α和细晶粒针状β二者的混合组织.随着保温时间的延长,后者将完全转变成粗晶粒等轴α组织,冷却方式对组织形貌影响不大.加热温度高于相变点时,TA17合金棒材的形貌空冷时为板条α 晶间β组织,水冷时为针状α'组织.保温时间对组织形貌影响不大.     

新型γ-TiAl合金的γ/α2层片形成机理

讨论了经过不同冷却速率、加热温度和保温时间对新型TiAl合金的γ/α2层片组织的影响。结果表明:热处理时间增加,层片晶团的晶粒有长大趋势,片层组织中出现层错,位错等缺陷;在不同冷却方式中,油冷组织中出现了块状γ,炉冷组织具有密集的层片。热处理温度在Tα相变点以上20℃内,片层晶团的晶粒最小,这是由合金中的弱β稳定元素Ta造成的。     

Ti-6.5Al-3.5Mo-1.5Zr-0.3Si合金β晶粒生长及片层组织转变

利用可控冷却速度热处理装置研究了Ti-6. 5Al-3. 5Mo-1. 5Zr-0. 3Si合金β热处理过程中的β晶粒生长及片层组织转变规律。结果表明,合金在β单相区固溶时,随着温度升高和保温时间延长,β晶粒尺寸增大,且加热温度高于1140℃时,β晶粒快速生长。计算了β相区晶粒生长激活能为129. 6 k J·mol-1,并建立了β晶粒生长模型。随冷却速度变化,合金出现全马氏体组织和(α+β)片状组织。原始β晶界在全马氏体组织和(α+β)片状组织中均清晰可见,原始β晶粒呈等轴状特征。(α+β)片以取向各异"集束"形式存在于原始β晶粒内,(α+β)集束内的α片几乎相互平行。(α+β)片层组织特征参数(原始β晶粒尺寸、α片厚度及(α+β)集束尺寸)均随冷却速度降低而增加。α片层可在β晶界和晶内形核,以集束形式生长,但不能穿过β晶界。原始β晶界能对α片层的生长起到约束作用。     

Ti-6Al-4V合金等温锻造过程微观组织演变研究

将原始组织为网篮组织的Ti-6Al-4V合金在β单相区(1010℃)保温30 min并淬火处理可以获得α'马氏体组织。研究了初始组织为α'马氏体的Ti-6Al-4V合金在2步等温锻造过程中微观组织演变规律。结果表明:经过960℃的第1步等温锻造后,合金中马氏体相分解转变为α+β片层组织,部分片层组织发生弯曲、碎化,形成等轴晶粒,同时,合金中残留大量片层组织。800℃第2步等温锻造后,残余片层全部碎化,再结晶转变为等轴α相,获得晶粒尺寸为1.3μm的均匀等轴组织。     

热处理冷却方式对TC10钛合金组织与性能的影响

对不同温度加热后的TC10钛合金棒材进行水冷、空冷、炉冷3种不同冷却方式的处理,通过光学显微镜、扫描电镜以及拉伸性能和冲击性能试验,研究了合金在不同冷却方式下的组织和力学性能。结果表明,TC10钛合金锻棒原始组织中α相有两种形态,一种为初生等轴α相,另一种为次生α相。当加热温度低于相变点时,形成的组织以双态组织和等轴组织为主,当加热温度高于相变点时,合金组织以全片层β转变组织和粗片层β转变组织为主。3种冷却方式下,水冷后合金的强度最大,炉冷后合金塑性最好。合金在炉冷后的冲击性能最高,其次为空冷、水冷。当加热温度在两相区时,3种冷却方式下合金的拉伸和冲击断口形貌包含韧窝和解理面,高低起伏明显;当加热温度在单相区时,合金的拉伸断口形貌为结晶状,撕裂棱明显,冲击断口具有晶间断裂特征。     

热轧态TC4合金不同热处理后的组织变化及硬度

通过热膨胀法测定TC4合金的(α+β)/β相变温度,研究不同温度、不同冷却方式下的热处理工艺对热轧态TC4合金的显微组织及硬度的影响。结果表明,(α+β)/β相变温度范围在970～990℃之间;(α+β)两相区温度范围内退火,随着温度的升高,α→β的转变程度增大,得到由等轴α和转变态β构成的双态组织;相变点以上温度退火,得到明显的魏氏组织;高温退火、冷速过快时,得到马氏体组织;高温退火对合金硬度的影响较大。     

固溶处理对TC4合金组织和硬度的影响

对TC4合金进行不同固溶处理,研究了固溶温度、保温时间、冷却方式对合金显微组织和硬度的影响。结果表明,随着固溶温度的升高,TC4合金由等轴组织到双态组织再到全马氏体组织转变,硬度逐渐增加;达到高温平衡状态时,延长保温时间对TC4合金显微组织和硬度的影响不明显;当固溶温度分别为925 ℃和975 ℃时,随着冷却速率的降低,α相在冷却过程中发生扩散长大,β转变组织从α'马氏体变为次生α相+β相的片层组织,硬度分别从水冷条件下的359~389 HV0.2降为空冷条件下的318~327 HV0.2;炉冷后得到全等轴组织,硬度较低,约300 HV0.2。     

热处理工艺对TA15钛合金棒材组织和性能的影响

研究了普通退火、β退火的单重热处理制度和强韧化的双重热处理制度对TA15钛合金棒材组织和性能的影响规律。结果表明,在普通退火温度范围内,合金组织形貌变化不大,均为等轴组织,合金的强度和冲击韧性随退火温度的升高而增加,塑性基本保持不变;β退火得到粗大的魏氏体组织,综合力学性能最差;在双重热处理过程中,第二重热处理温度主要影响片层α相的厚度,随着第二重热处理温度的升高,片层α相厚度增加,合金的强度降低,冲击韧性增加。当热处理制度为975℃×1 h/WQ+850℃×2h/AC时,合金组织由约24%的初生等轴α相、55%左右的网篮α相和β转变组织组成,此时合金具有良好的强韧性匹配。     

热加工工艺对Ti-1300合金轧制棒材显微组织的影响

研究了轧制温度、变形量以及热处理工艺对Ti-1300合金显微组织的影响,并讨论了热加工工艺与合金组织结构以及形貌之间的联系规律。结果表明:两相区轧制后的加工态Ti-1300合金主要由等轴的β相和球状α相组成,随轧制温度向合金相变点温度的升高,α相逐渐溶解在β基体上,因而β单相区轧制的合金主要由等轴的β相晶粒组成,而合金的晶粒随变形量的增加而破碎越充分,组织也更加细小、均匀。两相区固溶处理后的Ti-1300合金在晶界和晶间析出球状以及条状α相,弥散分布于亚稳定β基体,产生细晶强化效应,而β单相区固溶处理后的合金主要由平均晶粒尺寸为60μm的等轴β相组成。两相区固溶处理后的时效态Ti-1300合金的组织主要由条状初生αp相、针状次生αs相以及β基体组成,热轧温度和变形量对时效态Ti-1300合金中αp相的形貌特征影响较小,但αp相和αs相都随时效温度的升高而不同程度的长大,针状次生αs相弥散分布在β基体上。     

板坯组织类型及热处理工艺对Ti6321合金板材组织与性能的影响

结合力学性能测试和OM、SEM分析,研究了不同板坯组织类型和热处理工艺对Ti6321合金组织与性能的影响。结果表明：合金板坯的组织类型对轧制板材的组织与性能状态具有显著影响,经相同工艺轧制后,等轴组织板坯形成双态组织板材,魏氏组织板坯形成等轴组织板材。(α+β)/β相变点以下热处理,等轴组织板坯制备板材的纵、横向的屈服强度和抗拉强度低于魏氏组织板坯制备板材对应方向的强度,延伸率和冲击功则相反；随加热温度的升高,不同板坯组织制备的板材其屈服强度、抗拉强度略有降低,冲击功则急剧升高。高于(α+β)/β相变点热处理,两合金的拉伸性能和冲击功均明显下降。合金板材在α+β两相区热处理过程,初生α相对温度的敏感性高于对保温时间的敏感性。随着温度的升高,初生α相含量急剧下降,而次生片状α相含量明显增加。Ti6321合金板材适宜的热处理工艺为：(940℃～980℃)×(2～3)h。     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effect of Short-Time Aging on the Pitting Corrosion Behavior of a Novel Lean Duplex Stainless Steel 2002

The effect of short-time aging in the temperature range between 400 and 1000 °C on the pitting corrosion behavior and mechanical property of a novel lean duplex stainless steel(LDSS) 2002 was investigated through the potentiostatic critical pitting temperature(CPT) tests and the Charpy impact tests. Both the pitting corrosion resistance and the toughness of aged specimens degraded due to the precipitation of detrimental secondary phases and the most significant reduction of CPT and impact energy emerged at 650 °C concurrently. The CPT of LDSS 2002 specimen aged at 650 °C decreased by 28 °C, and the impact energy dropped from 69 to 29 J/cm~2 compared with the solution-annealed sample. Transmission electron microscopy characterization showed that the main precipitates in LDSS 2002 were Cr_2N and M_(23)C_6 along the ferrite–austenite grain boundaries.     

Information for Contributors

正The Transactions of Nonferrous Metals Society of China,founded in 1991 and sponsored by The Nonferrous Metals Society of China,is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology,including mineral processing,extraction metallurgy,metallic materials and heat treatments,metal working,physical metallurgy,powder metallurgy,with the emphasis     

Preface

<正>We are pleased to present this Special Issue of Transactions of Nonferrous Metals Society of China containing selected papers from the First Asian Conference on Aluminum Alloys(ACAA-2013),held in Beijing,China,13–17 October 2013.This conference has been initiated,with approval of     

Information for Contributors

The Transactions of Nonferrous Metals Society of China, founded in 1991 and sponsored by The Nonferrous Metals Society of China, is published monthly now and mainly contains reports of original research which reflect the new progresses in the field of nonferrous metals science and technology, including mineral processing, extraction metallurgy, metallic materials and heat treatments, metal working, physical metallurgy, powder metallurgy, with the emphasis on fundamental science. It is the unique preeminent publication in English for scientists, engineers, under/post-graduates on the field of nonferrous metals industry. This journal is covered by many famous abstract/index systems and databases such as SCI Expanded, Ei Compendex Plus, 1NSPEC, CA, METADEX, AJ and JICST.     

INTRODUCTION TO PATENTS

The invention provides a method of making a mold which can reduce SOx generation rate while preventing decrease in hardening rate in the case of using sulfuric acid for a hardener composition. The method has a mixture step in which fire-resistant particles, a hardener composition and a binder composition are mixed to obtain a composition for a mold. The hardener composition contains sulfuric acid. In the mixture step, sodium carbonate is added. A molar ratio of the sulfuric acid to the sodium carbonate is 0.5 or more and 4.0 or less.     

China Foundry Week 2014

China Foundry Week, hosted by the Foundry Institution of Chinese Mechanical Engineering Society （FICMES） each year, is a large academic event in China. It is one of the ten high-impact activities sponsored by the Chinese Mechanical Engineering Society.     

17th Conference of Hydrodynamic and Electromechanical Control Engineering Call for papers

正1.Contents In order to promote the academic exchanges and technical communication of the research in the field of fluid power transmission and control,fluid control engineering specialized committee of the Chinese Society of Theoretical and Applied Mechanics will hold the 17th Conference of Hydrodynamic and Electromechanical Control Engineering on July 27-29,2014 in Tibet,Lhasa city.     

Formulas of Tension of Continuous Rolling Process

The development of computer controlled continuous rolling process calls for a mathematical expression that can express the inequality condition of "constant flow". Tension is the link of the continuous rolling process. From the condition of dynamic equilibrium, a differential equation of tension is given out. On the basis of the physical rules established from the industrial practice and experimental studies, the law of volume constancy, the linear relation of forward slip and tension, the state equation of continuous rolling, the formula of dynamic tension, and the formula of static tension have been obtained. These formulae reflect the functional relations between tensions, thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuous rolling process is a gradually steady, controllable, and measurable dynamic system. An assumption of predicting the thickness of a steel plate using these tension formulae is also put forward.