热处理工艺对高强高导Cu-Cr-V-Zr-RE合金性能的影响

对Cu-Cr-V-Zr-RE合金进行热处理,研究了固溶温度、固溶时间、时效温度以及时效时间对合金显微硬度和电导率的影响。结果表明,该合金的最佳热处理工艺为920℃×1h固溶,550℃×1h时效。在该热处理工艺下,合金可以获得较好的综合性能,其显微硬度达到134HV,电导率达到80.5%IACS。     

固溶时效热处理对A286合金组织演变规律的影响

对A286铁基高温合金进行固溶温度+时效两段式热处理工艺优化研究。采用固溶热处理制度为930~1020℃/4 h/WC,固溶时间为0~4 h。合金时效研究采用640~790℃/4 h/AC热处理;在时效温度730℃条件下,研究0~16 h时效时间对合金组织及性能的影响。结果表明:随着固溶温度上升和时间延长,合金晶粒尺寸有一定程度长大,但硬度逐渐下降;随着时效温度提高及时间延长,合金的硬度先升高而后降低;在固溶热处理过程中,合金随着固溶处理温度提高及时间的延长,γ'相回溶入基体;当固溶后的时效温度提高至700℃才析出γ'强化相;随着时效时间延长,析出的γ'强化相发生粗化;合金时效γ'强化相粗化过程符合Ostwald熟化长大规律,计算值与实际值相关系数大于97%;同时,确定了最佳的热处理工艺制度。     

热处理工艺对6082铝合金组织和性能的影响

研究了形变后的6082铝合金热处理工艺参数对其组织和性能的影响。结果表明:合金固溶时效后获得大量均匀分布的Mg_2Si强化相;随着固溶温度升高、固溶时间和时效时间的延长,合金时效后的硬度呈现出先升高后降低的趋势。6082铝合金较适宜的热处理工艺参数为555℃×4 h固溶水淬+175℃×10 h时效处理。     

形变热处理对Cu-15Ni-8Sn系合金组织结构与性能的影响

利用力学、电学性能测试,金相显微分析、扫描和透射电镜观察等手段研究均匀化退火和形变热处理工艺对Cu-15Ni-8Sn-1.0Zn-0.8Al-0.2Si合金组织结构与性能的影响。合金铸锭经830℃,2 h+850℃,2 h双级均匀化退火处理,热轧变形后合金板材经850℃,1 h固溶处理,冷轧变形60%后,分别在400和450℃时效处理。当450℃时效时间为30 min时,合金硬度为3780 MPa,电导率8.0%IACS,抗拉强度1144 MPa,屈服强度1098 MPa,延伸率3.29%;在400℃时效1 h时,合金硬度为3900 MPa,电导率7.4%IACS,抗拉强度1164 MPa,屈服强度1112 MPa,延伸率3.05%。合金的强化效应主要来源于调幅分解强化、析出强化和亚结构强化的共同作用,同时,溶质原子的析出使基体固溶度降低,合金电导率提高。合金经双级均匀化退火处理后为均匀的等轴晶组织,在400℃,1 h时效过程中发生调幅分解,同时析出具有L1_2结构的β-Ni_3Sn析出相,其与Cu基体的晶体取向关系为:(002)_(Cu)‖(00 1)_β,[110]_(Cu)‖[110]_β;(220)_(Cu)‖(110)_b,[112]_(Cu)‖[112]_β。     

形变热处理对Cu-2.7Ti-0.15Mg-0.1Ce-0.1Zr合金组织和性能的影响

利用力学、电学性能测试和透射电镜观察等手段研究了形变热处理对Cu-2.7Ti-0.15Mg-0.1Ce-0.1Zr合金组织与性能的影响。结果表明:合金固溶后于450℃时效8 h呈典型的调幅分解组织,还存在纳米级强化相β’-Cu4Ti。合金经固溶处理后,冷轧97.5%,在400℃时效1 h时显微组织主要为亚晶组织+纳米析出相,亚晶尺寸约为40 nm。形变热处理能够有效提高合金的综合性能,合金经过97.5%冷变形、于400℃/12 h时效后,硬度为301 HV、电导率为20.9%IACS。     

焊后热处理对Al-Zn-Mg合金焊接接头组织与性能的影响

采用金相、硬度、电导率、剥落腐蚀、电化学腐蚀以及透射电镜(TEM)观察等分析测试方法研究焊后热处理对Al-Zn-Mg合金组织与性能的影响。结果表明:Al-Zn-Mg合金焊接接头固溶区的硬度和耐腐蚀性能随焊后热处理时效时间的延长和温度的提高而提升。自然时效4 d+(130℃,24 h)和自然时效150 d+(150℃,2 h)两种焊后热处理工艺较佳:经自然时效4 d+(130℃,24 h)处理后,合金固溶区最大硬度由82.5HV提高至123HV,最大电导率由34%IACS提高至35.8%IACS,剥蚀等级提升至EA;经自然时效150 d+(150℃,2 h)处理后,合金固溶区最大硬度提高至110HV,最大电导率至34.7%IACS,剥蚀等级提升至N。合金焊接接头固溶区硬度与耐腐蚀性能提升的主要原因是焊后时效热处理促进焊接固溶区晶内析出相粗化,弥散分布,且晶界析出相呈不连续分布状。     

热处理对铬青铜组织和性能的影响

研究了均匀化处理、固溶时效、冷变形时效等对铬青铜显微组织和性能的影响。结果表明:均匀化处理可有效改善铬在铜基体中的分布;铬青铜的最佳固溶工艺为:1000℃保温1h后水淬;较好的时效工艺为470℃×4h,此时合金的硬度和电导率分别为121.5HV和79.8%IACS。时效前经适当的冷变形,其硬度为146.7HV,电导率为85%IACS,和未冷变形直接时效相比分别提高了25.2HV和5.2%IACS。     

热处理对铬青铜组织和性能的影响

研究了均匀化处理、固溶时效、冷变形时效等对铬青铜显微组织和性能的影响.结果表明均匀化处理可有效改善铬在铜基体中的分布;铬青铜的最佳固溶工艺为1000℃保温1 h后水淬;较好的时效工艺为470℃×4 h,此时合金的硬度和电导率分别为121.5 HV和79.8%IACS.时效前经适当的冷变形,其硬度为146.7 HV,电导率为85%IACS,和未冷变形直接时效相比分别提高了25.2 HV和5.2%IACS.     

La变质4004铝合金的热处理

研究了固溶及时效处理对La变质4004铝合金组织及性能的影响。结果表明:随着固溶温度的升高、固溶时间的延长,合金中共晶硅熔断并粒化,500℃固溶6 h时性能达到最佳;随着时效温度的升高、时效时间的延长,合金硬度先升高后降低,时效温度为200℃、时效时间6 h时其硬度达到最高值112 HBW。变质4004铝合金最佳热处理工艺为:500℃×6 h固溶+200℃×6 h时效。     

VC-Cu-Cr-Zr复合材料组织与性能研究

根据时效强化和颗粒增强强化的双重强化机制,以Cu-Cr-Zr合金为基体,采用熔铸法制备了VC-Cu-Cr-Zr复合材料。较系统地研究了热处理工艺对VC-Cu-Cr-Zr复合材料组织和性能的影响。结果表明,热处理可明显提高VC-Cu-Cr-Zr复合材料的硬度和电导率,最佳热处理工艺为910℃×1 h固溶处理＋460℃×2.5 h时效     

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.