Ni-W-P-SiC脉冲复合镀层的腐蚀形貌研究

在四种腐蚀溶液中对Ni-W-P-SiC脉冲复合镀层进行浸泡试验,利用光学显微镜对镀层腐蚀后的表面形貌进行了分析。9天的浸泡试验结果表明,经400℃热处理的镀层在各种腐蚀介质中腐蚀后的表面形貌变化比镀态镀层小;镀层在HCl溶液中的腐蚀属于点蚀,在H2SO4、H3PO4和FeCl3溶液中的腐蚀属于缝隙腐蚀。     

稀土-Ni-W-P-SiC脉冲复合镀层的耐蚀性研究

采用腐蚀溶液浸泡、绘制阳极极化曲线和中性盐雾试验三种方法研究了稀土(RE)-Ni-W-P-SiC脉冲复合镀层的耐蚀性.结果表明:无论是在镀态条件下还是在400℃热处理条件下,脉冲RE-Ni-W-P-SiC镀层在各腐蚀溶液中的耐蚀性均优于相应的直流镀层,更优于不锈钢(1Cr18Ni9Ti);镀层在HCl、H2SO4、H3PO4溶液中的腐蚀速率都比较低,而镀层在FeCl3溶液中的腐蚀速率远大于前三者;脉冲频率f=33Hz,占空比r=0.6时获得的镀层具有较好的耐腐蚀性.表面形貌分析表明稀土-Ni-W-P-SiC脉冲镀层比其直流镀层平整细腻;相结构分析表明脉冲镀层经400℃热处理后非晶态减少并产生Ni3P新相.     

Ni-P-纳米TiO2复合镀层的耐蚀性研究

采用全浸泡腐蚀试验，系统研究了Ni—P-纳米TiO2复合镀层在HCl、H2SO4、HNO3、NaOH和NaCl溶液中的耐腐蚀性能。结果表明，Ni—P-纳米TiO2复合镀层比Ni—P化学镀层具有更优异的耐酸、耐碱、耐盐腐蚀的性能；复合镀层在盐和碱性腐蚀液中的耐蚀性优于酸性腐蚀液；Ni—P一纳米TiO2复合镀层在不同腐蚀液中的腐蚀形态明显不同，复合镀层在NaOH、NaCl和HCl溶液中的腐蚀形态为均匀腐蚀型，而在H2SO4和HNO3强氧化性介质中的腐蚀形态则为点蚀穿透型；保持镀层在腐蚀液中的完整性对提高镀层的耐腐蚀性能至关重要。     

Ni-P-Al2O3镀层的腐蚀、冲刷腐蚀和磨损行为

采用质量损失法系统研究了65Mn板材和W6Mo5Cr4V2高速钢钻头表面的Ni-P-Al2O3镀层的腐蚀、冲蚀和磨损行为。用扫描电镜(SEM)和能谱仪(EDS)进行形貌观察和成分分析。结果表明,Ni-P-Al2O3镀层的腐蚀和冲蚀性能优于316L不锈钢,镀层的腐蚀和冲刷腐蚀速率随介质温度升高而增大,400℃热处理降低镀层的腐蚀和冲刷腐蚀抗力。镀层在Na2S,HCl和H2SO4溶液中的腐蚀速率依次增大,在Na2S和H2SO4中发生均匀腐蚀,而在HCl溶液中则是局部腐蚀。在大气环境中,镀层的耐磨性不如高速钢基体。     

烧结NdFeB永磁体在不同酸溶液中的腐蚀行为（英文）EI北大核心CSCD

通过酸洗、浸泡法和电化学腐蚀测试分析了烧结Nd Fe B永磁体在不同浓度的H2SO4溶液、HCl溶液和HNO3溶液中的腐蚀行为。结果表明,烧结Nd Fe B磁体在HNO3溶液中的腐蚀机制为均匀腐蚀,而在H2SO4溶液和HCl溶液中的腐蚀机制为选择性的晶间腐蚀。烧结Nd Fe B磁体在酸溶液中的腐蚀速率随着酸溶液浓度的增加而增加。在浸泡试验和电化学腐蚀试验中,烧结Nd Fe B磁体在HNO3溶液中的腐蚀速率均最小。因此,HNO3溶液更适合作为烧结Nd Fe B磁体的酸洗液。     

烧结NdFeB永磁体在不同酸溶液中的腐蚀行为（英文）

通过酸洗、浸泡法和电化学腐蚀测试分析了烧结Nd Fe B永磁体在不同浓度的H2SO4溶液、HCl溶液和HNO3溶液中的腐蚀行为。结果表明,烧结Nd Fe B磁体在HNO3溶液中的腐蚀机制为均匀腐蚀,而在H2SO4溶液和HCl溶液中的腐蚀机制为选择性的晶间腐蚀。烧结Nd Fe B磁体在酸溶液中的腐蚀速率随着酸溶液浓度的增加而增加。在浸泡试验和电化学腐蚀试验中,烧结Nd Fe B磁体在HNO3溶液中的腐蚀速率均最小。因此,HNO3溶液更适合作为烧结Nd Fe B磁体的酸洗液。     

2205与15MnNiCrMoV异质钢焊接接头的耐蚀性能

双相不锈钢2205与低碳合金调质高强钢15MnNiCrMoV复合板焊接接头,35℃下,在质量分数为10%的HCl和H2SO4腐蚀溶液中,对其腐蚀产物进行了分析,结果表明,复合板焊接接头在HCl溶液中的耐蚀性较差,且热影响区的腐蚀程度均比焊缝处的严重;在H2SO4溶液中,焊接接头15MnNiCrMoV侧的腐蚀比在相同条件下的HCl中严重,尤其是热影响区对H2SO4的耐蚀性较差,而焊接接头双相不锈钢2205侧在H2SO4溶液中未发生腐蚀。其原因主要是在双相不锈钢表面形成了钝化型的Cr2O3、FeO、Cr-O等氧化物膜层。     

奥氏体不锈钢焊缝金属的电化学腐蚀性能

采用PASTAT30型恒电位仪测试了SUS 316奥氏体不锈钢钨极氩弧焊TIG,熔化极氩弧焊MIG和钨极氩弧焊加填丝TIG M焊缝金属的电化学腐蚀性能.结果表明,在质量分数9.8%H2SO4溶液中,母材及焊缝的抗电化学腐蚀能力由大到小的顺序为母材＞TIG M焊缝＞MIG焊缝＞TIG焊缝,在质量分数5.0%HCl溶液中为母材＞MIG焊缝＞TIG M焊缝＞TIG焊缝,由此可知TIG焊缝金属的抗腐蚀能力最弱.由Tafel曲线可知,SUS316奥氏体不锈钢在H2SO4溶液中的钝化区间较长,在HCl溶液中的钝化区间很短暂,所以不锈钢在盐酸溶液比硫酸溶液中抗腐蚀性能差.晶间腐蚀试验结果与9.8%H2SO4溶液中电化学腐蚀试验结果相同.     

用双层辉光等离子法在钛表面制备的Ti-Pd合金层性能研究

采用双层辉光等离子冶金技术在纯钛表面制备了Ti—Pd合金层。其深度大约为90μm，Pd含量呈梯度变化，并出现了TiPd3，TiPd2，Ti2Pd3，Ti3Pd5，TiPd，Ti4Pd等6种化合物相和Pd相。合金层在100℃的NaCl饱和溶液＋HCl溶液以及40℃的8．6％H2SO4溶液中的耐缝隙腐蚀性能优于Ti0．2Pd合金；在室温80％H2SO4的溶液中，腐蚀速率仅为0．682mm／a，是Ti0．2Pd合金的18．2％：在室温30％HCl的溶液中，表面Ti—Pd的腐蚀速率仅为0．004mm／a，是Ti0．2Pd合金的12．5％。     

电泳-电沉积镍基纳米复合镀层Ni-Al2O3的耐蚀性能

采用电泳-直流电沉积和电泳-脉冲电沉积工艺制备了具有较高Al2O3含量的Ni-Al2O3纳米复合镀层,分析了纳米粒子对复合镀层表面形貌及微观组织的影响,并以静态浸泡试验法研究了镀层在质量分数为l0％的HCl溶液和l0％的H2SO4溶液中的耐蚀性能.结果表明,相比于纯金属镀层,电泳-电沉积纳米复合镀层的晶粒细小、组织致密...     

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.     

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。     

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.     

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.     

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.