Sn-xSb合金与Cu基体的界面反应行为及热力学

研究不同Sb含量Sn-Sb合金在Cu基板上的界面行为,以明确Sb元素对Sn-Sb合金焊料焊接可靠性的影响。通过分析Sn-xSb/Cu体系的显微组织和界面反应热力学,解释界面层的演化过程。结果表明,添加Sb对金属间合物层的生长并非单调递增。Sb能抑制Cu在焊料中的扩散。添加3%Sb(质量分数)使界面反应活化能从286.41降低到62 kJ/mol,促进了界面反应的进行。随着Sb含量增加至10%Sb(质量分数),界面反应活化能提高到686.73 kJ/mol,使界面反应难度增加,减少焊料对Cu基体的熔蚀,并抑制过厚界面层的形成。

Dissolutive wetting process and interfacial characteristic of molten Sn–17Bi–0.5Cu alloy on copper substrate

The reactive spreading processes of Sn–17Bi–0.5Cu melt alloy on Cu substrate were studied by sessile drop method in the temperature range of 523–673 K.Dynamic contact angles between the solder and Cu substrate at different times were recorded with high-resolution CCD digital video.The smallest contact angle was observed at623 and 673 K.Ultimate spreading radius does not increase monotonously with the temperature increasing.These can be attributed to the strong dissolution of Cu substrate into the liquid solder,which hinders the solder from spreading.Triple line area configuration of the Sn–17Bi–0.5Cu/Cu system was discussed by the description of the equilibrium state.The calculated results based on experiments of the tension balances along each of the three interfaces show good agreement with theoretical analysis.Intermetallic compounds at the Sn–17Bi–0.5Cu/Cu interface are identified as Cu6Sn5adjacent to the solder and Cu3Sn adjacent to the Cu substrate,respectively.These results are of practical interest for composite lead-free solders’preparations and joining of Sn–17Bi–0.5Cu to Cu substrate.

不同渣系中固-液-气界面渣运动引起的SiO2基耐火材料局部熔损机理（英文）

观察不同渣系在SiO2基棱柱状耐火材料上的渣运动,并研究棱柱状耐火材料横截面形状的演变机理。存在两种类型的形状演变。对于其表面张力随SiO2浓度增加而增大的PbO-SiO2渣系,在轴向马兰戈尼剪切力和润湿性的作用下,渣膜沿着棱柱状耐火材料的4根棱边向上流;随后,在重力作用下,渣膜沿着棱柱的4个侧面流下;因为上升流和下降流中SiO2溶解度不同,棱边的腐蚀速率大于侧面的腐蚀速率,棱柱横截面由正方形演变为圆形。对于其表面张力随SiO2浓度增加而减少的FetO-SiO2渣系,在润湿性的作用下,渣膜向上流;之后,在马兰戈尼剪切力和重力的作用下,渣膜向下流;相比于4个棱边,由于4个侧面的表面张力和尺寸较大,渣主要在4个侧面上下运动;因此,棱柱横截面仍然保持为正方形。

Wettability and corrosion behavior between alkaline slag from sodium smelting of vanadium-titanium magnetite and refractory substrates

The sodium smelting of vanadium-titanium magnetite can achieve the comprehensive utilization of Fe,V,and Ti.However,the generation of alkaline slag during this process may cause damage to refractory materials.The wettability and corrosion behavior of alkaline slag on three types of refractory(MgO-C,SiC,and high alumina refractory)substrates were investigated at temperatures up to 1200℃.The effects of duration on the wettability of molten slag on SiC substrates were also investigated.Results showed that the high alumina refractory exhibited better wettability with the molten slag than the others,and thus,it is easier to be corroded.The results of scanning electron microscopy coupled with energy dispersive spectroscopy showed that MgO-C and high alumina refractory substrates were severely eroded.There was a visible and regular interfacial reaction layer between the slag and SiC refractory substrate,which was produced by the redox reaction between the metal oxides in the slag and the SiC refractory substrate.With the increase in holding time,the interface layer expands and silico-ferrite phases are generated at the interface.The redox reaction between Fe_(2)O_(3) and SiC substrate is the main reason for the corrosion.By comparing the differences in wettability and corrosion behavior between the alkaline slag from sodium smelting of vanadium-titanium magnetite and MgO-C,SiC and high alumina refractories,it is concluded that SiC refractory has good corrosion resistance to the slag.Iron oxides in the slag accelerate the oxidation rate of SiC refractory.

Wear-resistant coating spraying technique for wear-proofing cover of coke dry quenching furnace

During the operation of a coke dry quenching system of coking plant, wear-proofing cover of the boiler was seriously eroded, and even the ceiling tube of the boiler was worn and torn. Thus, attentions were paid to the research, development and application of the wear-resistant coating spraying technique for wear-proofing cover of the coke dry quenching furnace. The Cr3C2–NiCr coatings for wear-proofing cover were fabricated via supersonic arc spraying process, and the residual coating of wear-proofing cover would be sampled for being analyzed after two years. The coating presents a dense microstructure with few pores and micro-cracks (the porosity is 4.65%). After thermal spraying of the wear-proofing cover, the hardness and the wear resistance of the surface are improved. The remaining coating is continuous and compact, with an average thickness of about 147μm. Transverse micro-cracks parallel to the spreading direction of the coating surface are displayed on different areas of the coating, which demonstrates its serious erosion wear effect. The main chemical component of white zone is Fe–18Cr–Ni. The Cr level of light gray phase is about 77.57 wt.% and the O level is 22.43 wt.%. And the main chemical components of dark gray phase are C, O, Al, Si and Ca. X-ray diffraction patterns were adopted to implement phase analysis on the surface of coating sample, which indicated that the coating was composed of a large amount of Cr3O2 and a small amount of metal Cr.