Ag-Cu-In-Sn合金的结构特性

借助金相、X光衍射及SEM方法研究Ag-Cu-In-Sn合金的结构特性及合金各组元在合金相中的分布规律,还讨论了某些相结构对合金力学性能的影响。四元合金的化学成分是(wt％)57～63Ag,17～23Cu,(20—x)In,xSn,其中:Ag+Cu=80wt％,In+Sn=20wt％,2≤x≤16。     

Abnormal Austenite-Ferrite Transformation Behaviors of Fe-ISi: Dilatometric Measurements

WITH THE APPEASING of competition of the totaloutput of iron and steels, the new generation of ultrahigh strength steel, based on the lessen the burden ofenvironment, double improvement of mechanicalproperties and elongation of the serving life, has beenfully outspreaded in the world. More and more researchwork shows that the solid-state microstructureevolution becomes the most effective route in thedevelopment of ultra-high strength steels. A process ofgreat interest in the steel produc…     

Effect of binder-phase modification and Cr3C2 addition on properties of WC-IOC0 cemented carbide

For production of fine-grained and corrosion-resistant tungsten carbide (WC) based cemented carbides, addition of chromium carbide (Cr₃3C₂) in small amounts is standard practice. No systematic study, however, has been made of the effects of large additions (maximum 6 wt % ) of Cr₃C₂ as a substitute for tungsten carbide. This study focuses on the effect of hard-phase substitution by C₃C₂ in WC-1OCo cemented carbide. An attempt is also made to modify the binder metal cobalt by partial or complete substitution of nickel. Specimens were prepared using the standard liquid-phase sintering process and were tested for sintered porosity, mechanical properties, corrosion resistance, and microstructural parameters. Results confirm the findings of earlier workers regarding grain refinement and improvement of mechanical properties upon the addition of small amounts (<2 wt%) of Cr₃C₂. Modification of the binder phase improves indentation fracture toughness and corrosion resistance. Addition of Cr₃C₂ independent of the binder type improves corrosion resistance.     

Stress－rupture Property and Microstructure of Yttria Dispersion Strengthened Alloy MA956

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6×××系汽车车身板铝合金的合金化及组织性能的研究

采用力学性能试验和光学金相分析法,研究了Mg和Mn等元素对6×××系汽车板铝合金组织及性能的影响。结果表明:Mg和Mn是提高6×××系汽车板铝合金时效初期硬化值的元素,但对时效初期硬化速度影响不大。提高Mg和Mn含量,合金经170℃30min时效后的强度增大,伸长率降低。合金固溶处理淬火后的晶粒尺寸和形态不随Mg含量而改变,但随Mn含量增加而显著细化。     

湿法冶金制备的Ag—Pd合金粉末的固溶合金化研究

根据Ｘ射线衍射原理，建立湿法冶金固溶合金粉末的定量测定方法，可用于电子浆料合金粉末的检测，相对误差在±０．０１２５。     

Intermetallic phase formation in directionally solidified Al−Si−Fe alloy

The present study has been undertaken to better understand the solidification behavior of Al−Si−Fe alloys containing 7wt.% Si and 0.9wt.% Fe, with particular regard to the formation of phase during controlled solidification and influence of growth rates on intermetallic phase selection. The alloys studied were Al-7Si-0.9Fe alloys, which were produced by a modified Bridgman solidification arrangement. These alloys were solidified unidirectionally with different growth rates (1–30mm/min). The solidified microstructure of these alloys consists of the growth of primary aluminum and multiple second phase reactions.     

Valence band density of states of small cobalt particles on Si(111) substrate

Small Co particles were prepared by sputter etching of a 4–5 nm thick island-like Co film deposited on Si(111) substrate. The density of states (DOS) of the valence band was measured by means of ultraviolet photoemission (UPS) during the sputter etching to monitor the formation of small Co particles. It was found that at a given thickness of the Co island the Fermi level was shifted by 1.8-1.9 eV toward higher binding energy and theDOS decreased or no states were detectable at the Fermi level. This effect was explained by the formation of small Co particles with electronic structure which is significantly different from that of the bulk Co.     

Effects of Fe concentration on microstructure and corrosion of Mg-6Al-1Zn-xFe alloys for fracturing balls applications

Mg-6Al-1Zn-xFe (x = 0, 1, 3, 5 and 7 wt%) alloys were prepared by powder metallurgy and followed by hot extrusion. Majority of Fe element exists as insoluble particles in the alloys. The as-extruded alloys showed higher degradable rates but less stable mechanical properties than as-annealed alloys. Corrosion rate of all the alloys increased with increasing Fe concentration, reaching 2.4 mL cm⁻² h^-1. 0.2% yield strength of all the alloys was higher than 150 MPa. In short, Mg-6Al-1Zn-xFe alloys have an attractive combination of corrosion and mechanical properties, which holds a bright future for fracturing balls applications.