Zr和 Mg对快速凝固Cu-Cr合金时效析出过程的影响

快速凝固ＣｕＣｒ和ＣｕＣｒＺｒＭｇ合金经时效处理后显微硬度显著升高,在５００℃时效后,ＣｕＣｒ合金的硬度峰值为２０６ＨＶ,ＣｕＣｒＺｒＭｇ合金的硬度峰值为２５０ＨＶ。用透射电镜对两种合金时效过程中析出相的变化及其对显微硬度的影响进行了分析。ＣｕＣｒ合金达到峰值硬度时析出相为与母相共格的面心立方Ｃｒ,随后逐渐与母相失去共格关系并转变成体心立方的Ｃｒ。ＣｕＣｒＺｒＭｇ合金对应峰值状态的析出相为Ｈｅｕｓｌｅｒ相ＣｒＣｕ２（ＺｒＭｇ）,过时效状态下转变成面心立方的Ｃｕ５Ｚｒ和体心立方的Ｃｒ     

TiAl—Cr合金中的β2相

在Ｔｉ（４４～４８）Ａｌ（３～６）Ｃｒ（摩尔分数,％）的三元合金中,存在Ｂ２结构的体心立方有序β２相,其形成与含Ｃｒ量有关。β２相铸态成分可表示为：Ｔｉ５５Ａｌ３３Ｃｒ１２。β２相是该合金中显微硬度最高的相,其硬度值随合金中Ｃｒ含量增加而提高。β２相常分布于γ晶界,起阻碍晶粒长大作用。     

准铸态工艺对贝氏体铸铁组织和性能的影响

试验研究了一定合金成分下，打箱温度、冷却介质、保温方式和保温时间等工艺因素对铸铁组织和性能影响规律。结果表明，在ＭｎＳｉＣｕＣｒ低合金化处理条件下，利用铸件浇注后的高温打箱、余热淬火及贝氏体转变温度下充分保温的准铸态工艺，可使球铁和灰铸铁基体组织稳定转变为奥贝组织为主的复相组织，并使铸铁力学性能大幅度提高。     

连续冷却条件下Ti-1300合金的组织演变与连续转变图

通过OM、SEM、TEM和EBSD研究了Ti-1300合金在连续冷却条件下组织演变规律和亚稳β相的分解形式,并采用高精度膨胀法建立了合金的连续冷却转变动力曲线。结果表明：当连续冷却速度比较缓慢时,Ti-1300合金发生β → α + β转变,并获得集束状的显微组织;而当冷却速度0.3 °C/s ＜v＜ 1.5 °C/s时,Ti-1300合金发生β → α + β + β_m,并获得细针状的α + β组织和残余的β_m相;当冷却速度大于3 °C/s时,Ti-1300合金基本获得全部β相,所以把3 °C/s认为是合金的临界冷却转变速度。在缓慢冷却过程中,Mo当量梯度是合金中α相生长主要动力。随着冷却速度的增加,Ti-1300合金的显微硬度先增加后降低,在冷却速度为0.3 °C/s时,显微硬度达到最大值。     

Laves相TiCr_2的相变特征

用Ｘ射线衍射仪分析了Ｔｉ６４％Ｃｒ（摩尔分数）合金在经过不同的热处理后的相结构,使用ＴＥＭ分析了该合金的亚结构。结果表明：Ｌａｖｅｓ相ＴｉＣｒ２的Ｃ１４→Ｃ１５相变速度很慢,室温下得到的是Ｃ１４和Ｃ１５混合相结构。Ｃ１５ＴｉＣｒ２的亚结构由细微的孪晶组成,这些孪晶是在Ｃ１４→Ｃ１５相变过程中由于产生了切变而形成的。Ｌａｖｅｓ相ＴｉＣｒ２的Ｃ１４→Ｃ１５相变是切变型相变,通过热处理引进过饱和空位和残余应力可以加快ＴｉＣｒ２的Ｃ１４→Ｃ１５相变速度。     

热处理对TC21钛合金显微组织的影响

对TC21钛合金进行双重固溶+时效热处理,研究固溶冷却速率、温度对合金显微组织的影响。研究表明,初生α相形貌主要受一次高温固溶温度控制,高温固溶冷却速率对次生α相含量及长宽比有显著的影响。高的固溶冷却速率可以保留更多的亚稳定β相,从而在时效过程析出更多细小的次生α相,导致强度增加,塑性及韧性下降。二次低温固溶温度对合金后续的时效响应有显著的影响,高的固溶温度可以保留更多的β相,促使更多细小的转变α相在时效中析出;低的固溶热处理温度导致固溶残余β相相含量减小,时效敏感性降低。时效过程导致残余β相的分解,特别是大块亚稳定β相区。     

两相区热处理对TC21钛合金显微结构的影响

采用金相显微镜和扫描电镜等手段，研究了固溶、固溶时效等热处理工艺对TC21钛合金显微组织的影响，确定了两相区热处理得到的显微组织，采用透射电镜、X射线衍射方法研究了TC21钛合金在两相区热处理的相组成。同时探讨了固溶温度、固溶时间、冷却方式以及时效处理对这种合金显微组织和相结构的作用。结果表明：在两相区进行热处理，均得到双态组织；相组成主要是α相、β相，并在TC21合金中发现含有少量金属化合物，如α2-Ti3Al相、B2相、Zr3Al、Si2Mo等；固溶温度影响了初生α相的体积分数和晶粒尺寸：固溶时间达到一定程度后，延长保温时间对显微组织没有明显影响；冷却速度影响声转变基体组织；时效也对β转变基体组织和次生α相有影响。     

BASCA热处理对TB18钛合金显微组织和力学性能的影响

研究了TB18钛合金棒材经β固溶缓慢冷却时效（BASCA）热处理后的显微组织和力学性能。结果表明，TB18钛合金棒材在β相区固溶后缓慢冷却条件下，α相在β晶界和晶内均有析出，晶内α相呈点状或短针状，晶界α相基本呈薄膜状镶嵌在β晶界上。冷却速度对晶界α相影响较大，当冷却速度为1℃/min时，晶界α相以透镜状在晶界上不连续析出，形成“项链”组织。随着冷却速度的降低，析出的晶界α相越来越多且相互连接为一体，并逐渐粗化呈连续的波浪状。缓慢冷却后形成的晶界α相对合金塑性和韧性不利，随着冷却速度的减小，合金塑性和韧性均降低。TB18钛合金棒材经过β相区固溶空冷+时效处理后，可获得在抗拉强度接近1300 MPa的水平下，延伸率达到8%，断裂韧性超过80 MPa·m1/2的优异综合性能。     

快速凝固Cu-Cr-Zr-Mg合金的时效析出与再结晶

对快速凝固Ｃｕ０．６Ｃｒ０．１５Ｚｒ０．０５Ｍｇ合金伴随时效析出的再结晶过程进行了观察和研究。发现该合金在形变后的时效过程中,析出相非常细小、弥散,阻碍了再结晶的进行,出现了原位再结晶与不连续再结晶同时发生的现象。在再结晶的形核和长大过程中,析出相在晶界前沿快速粗化或重新溶解,并在再结晶区域中重新析出,导致更加弥散的析出相分布。     

涂层对TiAL金属间化合物抗循环氧化性能的影响

研究了渗铝、Ｃｏ３０Ｃｒ６Ａｌ０．５Ｙ（质量分数,％）和反应溅射Ａｌ２Ｏ３及Ｔｉ５０Ａｌ１０Ｃｒ（摩尔分数,％）涂层对ＴｉＡｌ金属间化合物在９００和１０００℃的循环氧化性能的影响。结果表明：几种涂层均不同程度地提高了ＴｉＡｌ的抗循环氧化性能,其中ＴｉＡｌＣｒ涂层表现出最好的效果。渗铝涂层内出现大量贯穿性裂纹;ＣｏＣｒＡｌＹ涂层和基体之间存在严重的互扩散,形成的孔洞已连成了较大的裂纹,且涂层内出现裂纹;Ａｌ２Ｏ３膜易开裂剥落,提高ＴｉＡｌ的抗循环氧化性能十分有限;而ＴｉＡｌＣｒ涂层表现出好的涂层基材相容性,循环氧化后涂层内没有出现裂纹,涂层－基材结合致密。     

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.