退火及冷却方式对5182铝合金屈服平台的影响

利用力学性能测试及显微组织观察研究了退火及冷却方式对5182铝合金板材屈服平台的影响。结果表明:在相同温度退火时,水冷合金板材的屈服强度比空冷合金板材的低;提高退火温度后,无论是水冷还是空冷都可以在一定程度上缩短合金的屈服平台,相比于退火温度影响,冷却方式对屈服平台的影响更大,水冷可以明显缩短甚至消除屈服平台;板材在420℃退火保温1～3 min时晶粒尺寸约16μm,当退火温度升高到480℃时,其晶粒尺寸在3 min内由21. 6μm长到了28. 0μm,其中有部分晶粒发生了异常长大;随着晶粒尺寸的增大,合金的屈服平台也略有减小;通过高温退火和水冷的方式可以消除合金的屈服平台。     

变形率及退火制度对Al-Mg合金薄板力学性能及微观组织的影响

通过力学性能测试及显微组织观察,研究了不同变形率的Al-Mg合金薄板在120～400℃进行2～8 h退火后的强度及显微组织的变化规律。力学性能测试结果表明:在回复阶段,不同变形率板材的强度随退火温度的升高近似线性降低。在同一温度退火时,保温时间对力学性能的影响较小,强度降低在10 MPa以内。只有变形率为71%的板材在220～240℃退火时随着保温时间的延长强度下降较多约20 MPa。变形率为23%和71%时,再结晶开始和结束温度分别为260℃、280℃和220℃、260℃,并且保温时间对再结晶温度没有影响。通过显微组织观察发现,再结晶完成之后板材的平均晶粒尺寸随变形率的增加而减小,由45μm减小到15μm,并且不随退火温度的升高及保温时间的延长而增加。当变形率大于71%时晶粒尺寸不再随变形率的增加而减小。     

退火温度对车用AZ91D镁合金板材室温拉伸断裂性能的影响

通过金相显微测试仪和力学拉伸试验仪器,分析了500～700℃退火温度下车用AZ91D镁合金板材室温拉伸力学性能以及断裂组织。研究结果表明:随着退火温度的增加,合金的晶粒尺寸逐渐增大,材料的抗拉强度降低。伸长率先增大后降低,并且在600℃下达到最大值,500,600与700℃温度下退火得到的试样的平均晶粒尺寸分别为4. 3,8. 5与15. 6μm;随着退火温度的增加,板材拉伸断口附近的显微组织中孪晶组织增加,孔洞变小,在500℃退火得到的镁合金板材断口区域存在一条明显的裂纹;随退火温度的增加,板材拉伸断裂机制为微孔聚集型断裂和解理断裂共同存在的混合型断裂。     

中间退火对5052铝合金组织与性能的影响

研究了中间退火对5052铝合金板材组织与性能的影响。对合金的拉伸性能及显微硬度进行测试,使用扫描电镜(SEM)对合金的断口形貌进行观察,使用金相显微镜及X射线衍射仪(XRD)对合金的显微组织和宏观织构进行分析。结果表明:经过中间退火的5052铝合金板材的屈服强度比直接轧制的低10 MPa左右,晶粒尺寸大约82%。中间退火试样不同方向的断后伸长率差别不大,而直接轧制试样的轧向较45°和90°方向的断后伸长率小9%,具有明显的各向异性。拉伸变形后中间退火试样晶粒沿最大切应力方向呈明显的流变特征,断口处韧窝发达、分布更均匀。中间退火试样的{100}001 Cube织构和{100}011 H织构等再结晶织构更强,而直接轧制试样的B织构{110}112和Goss织构{110}001等轧制织构更强。经中间退火的板材各向异性得到明显改善。     

不同温度重度变形及退火对工业纯铝组织的影响

采用重度冷轧及退火工艺制备超细晶工业纯铝,利用透射电镜和显微硬度实验对比研究了室温轧制和深冷轧制（液氮）及退火工艺所得到的超细晶工业纯铝组织特性和硬度。结果表明：深冷轧制细化晶粒的能力高于室温轧制,前者等轴状超细晶粒尺寸约为0.5μm,后者则约为1μm;深冷轧制试样的硬度值均高于对应状态下的室温轧制试样,温度低于200℃退火时,硬度值变化平缓,显微组织处于回复阶段;高于200℃退火时,硬度值迅速下降后趋于定值,与原始退火态相当,显微组织处于再结晶阶段。     

退火工艺对高碳Nb521合金板材组织和性能的影响

通过对不同退火工艺下高碳Nb521合金板材力学性能和组织状态以及退火过程中析出相的分析,研究了退火工艺对高碳Nb521合金板材组织和性能的影响。结果表明:随着退火温度升高,高碳Nb521合金板材的屈服强度、抗拉强度、维氏硬度变化不大,延伸率波动较大。退火温度升高到1 450℃,平均晶粒尺寸增大到29μm。SEM及EDS结果表明,退火后的高碳Nb521合金板材析出了点状碳化物并弥散分布在板材晶粒当中,片状碳化物分布在晶界上。1 400℃退火的高碳Nb521合金板材综合力学性能较好。     

中间退火后冷轧变形量对2E12铝合金组织和性能的影响

对中间退火后不同冷轧变形量的板材显微组织进行了对比分析,利用电子背散射衍射(EBSD)观察了不同变形量轧制的板材纵向面的晶粒再结晶、亚晶分布情况,采用中心穿透裂纹(CCT)试样测定了疲劳裂纹扩展速率,研究了中间退火后冷轧变形量对板材的晶粒取向和耐损伤性能的影响规律。结果表明,随着中间退火后的冷轧变形量的增加,晶粒细化,且小角度晶界的数量减少;中间退火后的冷轧变形量为40%时,其力学性能最为优异,但变形量增加至50%时,其裂纹扩展速率不合格;2E12铝合金薄板中间退火后的冷轧变形量以40%为宜。     

喷射沉积2195铝锂合金轧制板材晶粒组织及性能控制研究

研究了喷射沉积制备2195铝锂合金锭坯挤压板坯经不同终轧温度热轧至6mm厚度板材,以及经不同中间退火后再冷轧至6mm厚度板材固溶后的晶粒组织。结果表明,终轧温度290℃时,热轧板固溶后表层为粗大再结晶晶粒,而中心层为细长纤维状晶粒;终轧温度降低至220℃时,虽然表层再结晶晶粒尺寸减小,但中心层转变为尺寸粗大的长条状再结晶晶粒。板材中尺寸1μm以上的富Cu第二相粒子数量随中间退火(空冷)温度的增加(从330℃提高至450℃)而增加;冷轧固溶后表层等轴状再结晶晶粒尺寸增加,而中心层晶粒逐渐由粗大长条状再结晶晶粒转变为细小等轴状再结晶晶粒。适当温度中间退火、随炉冷却并冷轧、固溶后表层和中心层全部为细小等轴状再结晶晶粒。优化中间退火后的冷轧板材T8时效态强度最高,而终轧温度220℃的热轧板材T8时效态强度最低。     

温度对01420铝锂合金轧制开裂及晶粒细化的影响

采用形变热处理方法制备了01420铝锂合金细晶板材,研究了预热温度、中间退火温度对板材轧制开裂及晶粒细化的影响.结果表明:板材在低温(＜300℃)轧制时常常开裂,将开轧温度提高到400℃,在53%～70%轧制变形量后将板材在340～400℃退火2 h,可解决开裂问题.但中间退火温度对最终的再结晶晶粒大小有很大影响:温度为400℃时,合金发生了明显的部分再结晶,位错密度大大降低,虽获得了82%变形量的无开裂的板材,但再结晶后的晶粒粗大,平均晶粒尺寸约为16μm.温度为340、370℃时,合金发生了回复,无明显的再结晶发生,且退火温度越低,所保留的位错密度越高,81%轧制变形量的合金再结晶晶粒尺寸约为11μm.     

Mn含量对Al-Mg合金板材组织与性能的影响

通过拉伸试验和扫描电镜/能谱以及金相分析,研究了Mn含量对Al-Mg合金均匀化组织、退火后的力学性能及显微组织的影响。研究表明,两种成分合金均匀化组织中弥散相多为近等轴状粒子,尺寸约1μm,低Mn含量合金均匀化组织中弥散相数量少于高Mn合金均匀化组织中的弥散相;经480℃×10 s退火后高Mn含量和低Mn含量合金屈服强度分别为113 MPa和84 MPa,断后伸长率分别为23%和26%,退火再结晶平均晶粒大小分别为17μm和27μm。提高合金中Mn含量,板材强度增大,伸长率降低,退火再结晶晶粒尺寸减小;延长退火保温时间,两种合金屈服强度都有所降低,合金显微组织再结晶晶粒随着退火保温时间延长逐渐增大,伸长率逐渐增加。     

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.