What is a Solid State Reaction?

Solid state reaction refers to the process of different metals or compounds reacting through solid state diffusion. It is mainly used to prepare amorphous films or amorphous powders.

Because this method forms an amorphous state

The solid-state reaction periodic lamellar structure is a kind of highly regular micro-nano-scale self-generating composite multilayer film structure, and the film layer interface is well combined, which is one of the development directions of future functional thin film material preparation technology. The "diffusive stress model" explains the formation mechanism of the solid-state reaction periodic lamellar structure, and gives predictions for the microstructure characteristics of the new system. In this work, the periodic lamellar structure of the Zn / Ni3Si solid-state reaction system was studied using scanning electron microscopy and energy spectroscopy (SEM-EDS), and it was confirmed that the formation characteristics of the periodic lamellar structure of the Zn / Ni3Si system were consistent with the prediction of the diffusion stress model.

The solid-state reaction periodic lamellar structure was discovered by K. Osinski et al. In 1982. The solid-state reaction systems known to form periodic lamellar structures are: Zn / Fe3Si, Zn / Co2Si, Zn / Ni3SiZ, Mg / NiSOCozoFe3o , Ni / SiC, Pt / SiC, Co / SiC, Mg / Si02, AI / UoMo. AI / (Ni, W), Zn / Ni3Si, and recently discovered Zn / CuxTiy reaction system.

The CuXTiY alloy sample used in this experiment was prepared by vacuum melting a metal chip and copper wire with a purity of 99.99 wt.% According to a certain ratio. Ni3Si alloy is prepared by vacuum smelting of metallic nickel blocks and crystalline silicon wafers with a purity of 99.99%. The vacuum quartz tube is sealed, and it is removed after 1073K heat preservation for 14 days. In order to ensure good reaction interface bonding, Zn / CuxTiy diffusion couple and Zn / Ni3Si diffusion couple (purity of 99.999wt.% Zn) were prepared by melting contact method. The diffusion couples in each group were taken out of air cooling after holding at 663K for different periods of time. After metallographic treatment, the morphology of the reaction zone of the diffusion couple was observed using a field emission scanning electron microscope (SEM, Zeiss SIGMA), and the composition of the phase zone was analyzed using an energy-latent analyzer (EDS, TEAM EDS) ^[2]

Through high-power scanning electron microscope observation and energy spectrum analysis, it was confirmed that the periodic layered structure of the Zn / Ni3Si system was composed of single-phase and dual-phase layers alternately at the initial stage of formation, which was in line with the prediction of the diffusion stress model. During the process of reaction diffusion, the periodic lamellae structure of the Zn / Ni3Si system will undergo further phase transition, and gradually change from a single-phase and dual-phase alternating structure to an alternating structure composed of two types of single-phase lamellae with different compositions. In Zn / CuxTi, solid state reaction system, we also found a similar phase transition process.

This article reviews the latest research progress on the solid-state reaction cycle lamellar structure. Experiments have confirmed that the periodic lamellar structure of the Zn / Ni3Si system is composed of single-phase laminae and dual-phase laminae alternately at the initial stage of formation, which is consistent with the prediction of the diffusion stress model ^[3] .