Microstructures and electrochemical behaviors of as‐cast magnesium alloys with enhanced compressive strengths and corrosion decomposition

Abstract

Rapidly disintegrating alloys with enhanced compressive strengths and corrosion rates are prepared for fracturing parts in petroleum extraction. Extrusion casting is used to prepare Mg-xZn-Zr alloys by adjusting zinc content. Mechanical and electrochemical behaviors are investigated to evaluate the practicability as decomposable materials. Superficial topographies, compositions, phases, and distributions are also characterized to determine the dissociative mechanism. The results make clear that matrixes and secondary structures with reticulate shapes arise on surfaces. The material also possesses enhanced compressive strength to guarantee stabilization and pressureholding ability among decomposition. Concurrently, with the increase of zinc content and decomposition time, galvanic corrosion aggravates resulting in gradually reduced corrosion potentials and accelerated decomposition rates. Rapid material dissolution mainly attributes to anode corrosion of matrixes, peeling of microparticles, and inferior tolerance of corrosive products to dissolution. Such work highlights potential applications of fracturing materials for ensuring rapid decomposition and guaranteeing stable stress tolerance.

Enhanced Mechanical and Degradation Properties of Hollow Glass Microspheres/Mg Matrix Composites by Incorporating Copper Power for Degradable Downhole Tool Applications

“…While the network Al 2 CuMg phase could lead to the formation and accumulation of the corrosion product layer on the surface, inhibiting the degradation rate. The current HGM/MA‐1Cu composites exhibited the highest degradation rate of 88.65 mg·cm −2 ·h −1 in 3 wt% KCl solution at 366 K, and a favorable UCS of 352 MPa, which was compared favorably with the degradable Mg‐based materials recently reported, such as Mg4Zn4Ni, [ 19 ] Mg14ZnZr, [ 6 ] Mg17Al5Zn3Si, [ 1 ] and so on, suggesting it was a promising candidate for degradable downhole tool applications.…”

“…Element alloying and introducing reinforcement particulates have been proved the effective methods to adjust the performances of the magnesium. Recently, some Mg-based alloys/composites that can be used for degradable downhole tools have been developed, such as Mg─Zn─Zr alloy, [6] Mg─Ni─Y alloy, [3] Mg─Al─Zn─Si alloy, [1] FAC/Mg alloy composites, [7] hollow glass microsphere (HGM)/ Mg alloy composites, [8,9] and so on. The addition of some hardening metal elements (such as Al, Zn, Zr, RE, et al) can significantly strengthen the Mg alloys.…”

“…Meanwhile, due to the difference of the electrode potential between these second phases with the Mg matrix, the formation of them can also bring out different influences on the corrosion resistance of the Mg alloys. [3,6,10] Among these elements, the effects of Al and Zn on the performances of Mg alloys have been reported by many researches, these studies indicated that Mg alloys containing high Al (10-20 wt%) and Zn (2-10 wt %) contents exhibited excellent compressive strengths and corrosion rates. [11] In our previous studies, [8,9] the Mg alloy with high Al and Zn contents (Mg─15Al─5Zn) was chosen as the matrix, a novel Mg-based composites was developed through adding HGM into the Mg alloy (denote as HGM/MA composites).…”

Impact of nano‐SiCP and nano‐hBNP on the corrosion performance and fatigue behavior of Mg–Zn hybrid nanocomposites

“…Zn has been used to enhance resistance to corrosion and strength of Mg by refining the grains, strengthening the solid solution, and precipitation hardening. [5,6] In Mg alloys, Zn has the highest solid solubility (6.2 wt%) that facilitates the formation of coherent binary compounds with Mg. [7] Alloys of Mg-Zn are currently the commonly useful Mg alloys, apart from the alloys of Mg-Al. [8] Even though a larger quantity of Zn will improve the alloy's strength because of the effects of solid solution hardening, it decreases corrosion resistance due to increased galvanic corrosion caused by higher second-phase content.…”