复杂多元Cu-Fe-P-Zn-Sn-Mg合金的冷加工硬化及再结晶温度研究

对复杂多元Cu-Fe-P-Zn-Sn-Mg合金的冷加工特性进行研究,绘制其加工硬化曲线。通过测试不同退火态复杂多元铜合金的抗拉强度、伸长率及硬度,并进行显微组织观察,拟合出抗拉强度与退火温度、加工率之间的曲线,确定出合金的再结晶温度。结果表明,Cu-Fe-P-Zn-Sn-Mg合金具有明显的加工硬化特性,随着加工率的增加,该合金的抗拉强度和硬度增加,而伸长率则呈相反的变化规律。当加工率达到80%时,合金抗拉强度可达560 MPa,硬度可达160 HV。在相同的退火时间下,随着退火温度的增加,该合金的抗拉强度呈先缓慢减小,再剧减,最后趋于稳定的变化规律。合金在不同退火温度及加工率条件下,其抗拉强度与退火温度和加工率之间的关系符合y=(2.65ε+28.05)/[1+e^(x+1.62ε-503.04)/(0.006ε+19.06)]+0.22ε+307.68。为有效减少能耗和缩短生产周期,确定Cu-Fe-P-Zn-Sn-Mg合金经80%变形后的合理再结晶退火制度为450℃×1 h。     

HSn88-1合金冷加工硬化及再结晶温度的研究

对HSn88-1合金进行了不同程度的冷变形,绘制出合金的加工硬化曲线。通过对不同厚度退火后试样的抗拉强度和伸长率的测试和组织观察,得出了合金的再结晶温度。结果表明,合金经冷轧变形后具有明显的加工硬化效果。合金的强度随加工率的增大是先增大然后趋于稳定,而伸长率和电导率呈相反变化规律。此外,冷加工率越大,合金的开始再结晶的温度越低。     

Cu-Ag合金的冷加工硬化及再结晶温度

对Cu-Ag合金进行了不同程度的冷变形,绘制出了合金的加工硬化曲线。通过对不同厚度退火后试样的抗拉强度和伸长率进行测试和组织观察,得到了合金的再结晶温度。结果表明,合金经冷轧变形后,具有明显的加工硬化效果。合金的强度随着变形量的增大,呈先增大后趋于稳定的趋势,而伸长率、电导率与变形量呈相反的变化规律。冷变形程度越大,合金的再结晶温度越低。但当变形量超过60%时,再结晶温度趋于一个稳定值(300~400℃)。     

冷轧及退火对LA141镁锂合金组织及性能的影响

对热挤压LA141镁锂合金进行了冷轧和退火处理,研究了不同冷轧变形量及退火工艺对轧板显微组织及力学性能的影响。结果表明,热挤压态的LA141镁锂合金可进行大变形量的冷轧,最大变形量可达95%。随着变形量的增加,加工硬化程度增加以及晶粒细化使合金的抗拉强度升高,抗拉强度最高达到253.4 MPa,而伸长率由于晶粒细化作用程度不同而呈现先降低后升高再降低的趋势。退火后,合金发生回复和再结晶,其抗拉强度下降,在250℃×1h工艺下,合金发生完全再结晶,晶粒细小,具有较高的强度和伸长率。     

退火温度对冷轧态3003铝合金组织性能的影响

利用光学显微镜观察3003铝合金铸轧板、冷轧板以及冷轧板退火后的显微组织,用电子拉伸试验机进行拉伸试验,获得不同退火温度下铝板的力学性能,讨论了退火温度对该合金显微组织、抗拉强度和伸长率的影响.结果表明,随退火温度升高,抗拉强度下降,达一定温度后趋于稳定,伸长率的变化规律则相反;从而确定3003合金的再结晶温度为460℃.     

冷轧与退火对LA91合金显微组织和力学性能的影响

对热挤压态LA91合金进行了冷轧及退火处理,研究了不同冷轧变形量与退火温度对合金显微组织和力学性能的影响。结果表明,总轧制变形量为76.7%的LA91合金薄板具有较高的强度和良好的塑性(抗拉强度为177 MPa,伸长率为37.4%)。在200~300℃范围内退火,冷轧LA91合金发生回复和再结晶,β相逐渐变为等轴状,α相逐渐球状化。因此,随退火温度升高,合金薄板的抗拉强度先降低后升高,伸长率则先升高后降低。同一变形量下,合金中的α相再结晶温度略高于β相;经1h退火,不同变形量的冷轧LA91合金开始再结晶的温度略微不同,约为250℃,退火温度为300℃时,再结晶完成。     

Ti（50）Ni（47）Fe3形状记忆合金冷轧变形后的组织与性能

采用拉伸测试、维氏硬度测试、电阻率-温度曲线测试及扫描电镜和透射电镜观察显微组织的方法研究冷轧变形量为25%的Ti50Ni47Fe3合金经450-750°C下1 h退火后的显微组织和性能。结果表明,冷轧变形增强了合金的抗拉强度和屈服强度,冷轧变形后形成的应力场有助于R相变的发生。随着退火温度的升高,合金的抗拉强度和屈服强度下降,伸长率增大;当退火温度高于650°C时,强度和伸长率趋于稳定。电阻-温度曲线表明,在升、降温过程中发生两阶段相变B2-R-B19′。随着退火温度的升高,合金的相变温度降低;当退火温度高于650°C时,相变温度趋于稳定。随着退火温度的升高,合金依次发生回复、再结晶和晶粒长大。     

再结晶退火对AZ31镁合金挤压板材组织与性能的影响

利用光学显微镜和扫描电镜对AZ31镁合金挤压板再结晶退火前后的显微组织和断口形貌进行分析,并通过室温拉伸试验研究了再结晶退火前后的力学性能.结果表明,随退火保温时间的延长,板材先出现大量片状退火孪晶,随后退火孪晶消失,变形组织被细小、均匀的再结晶晶粒所取代;再结晶退火后,挤压板伸长率增加,抗拉强度提高;退火后试样断裂时宏观断口呈现撕裂棱与韧窝共存的形貌,呈韧性断裂,且随着合金晶粒尺寸减小,撕裂棱和韧窝更加细小.     

Ti-B20合金冷轧板材的再结晶行为

对固溶态Ti-B20合金进行70%压下量的冷轧变形，然后在800℃下进行不同时间的退火处理。采用电子背散射衍射(EBSD)技术和X射线衍射(XRD)研究了Ti-B20合金冷轧板材在退火过程中的静态再结晶行为和力学性能演变。结果表明：在退火过程中，合金的再结晶晶粒优先在晶界处和变形带处形核，导致退火初期组织不均匀；随退火时间的延长，晶粒逐渐等轴化，几何必要位错(GND)密度逐渐减小并趋于稳定，抗拉强度逐渐降低，而伸长率逐渐增加；在退火30 min后，Ti-B20合金冷轧板材的抗拉强度和伸长率分别为828 MPa和23.9%。合金再结晶体积分数与退火时间之间的关系可用Johnson-Mehl-Avrami-Kolmogorov(JAMK)方程来描述(X₈₀₀=1-exp(-0.26×t^0.74))。     

热处理对Ti-Ni合金显微组织和力学性能的影响

研究了冷加工变形量为48%的Ti-Ni合金经中温退火(350～600 ℃)处理后退火温度对合金显微组织及室温力学性能的影响.结果表明,变形后获得部分非晶的纳米组织,400 ℃退火后合金发生再结晶;500 ℃退火后完成再结晶,晶粒开始长大;600 ℃退火后合金组织完全粗化,室温下为粗大的自协调马氏体.退火温度升高,合金的抗拉强度大大下降,当退火温度高于500 ℃时,伸长率大大增加,伸长率大于50%.室温下合金拉伸变形时应力诱发马氏体相变的临界应力值σs受退火温度和相变温度的制约.     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

THERMODYNAMICS STUDY ON THE DECOMPOSITION OF CHROMITE WITH KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

INFLUENCE OF HEAT TREATMENT ON DAMPING BEHAVIOUR OF THE MAGNESIUM WROUGHT ALLOY AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.     

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。     

A STUDY OF TEMPERATURE-DEPENDENT VALENCE BOND STRUCTURE OF TITANIUM

On the basis of energy and shape method for the determination of the valence bond (VB) structures of crystal, the valence bond structure of titanium is redetermined at room temperature and calculated in the whole temperature range of 0-1943K. The outer shell electronic distribution of Ti is e_c~(2.9907) · (s_c~(0.4980) d_c~(2.4927)) ef1.0093 in crystal. The temperature dependences of the VB structures of hcp and bcc phases are the same. The VB structures of hcp and bcc phases monotonically increase or decrease with the increase in temperature, but show discontinuous changes at the phase-transformation temperature 1155K.