Dual-phase Mg-Li alloys are promising for industrial applications due to their low density and superior plasticity, but their low hardness limits performance under high-stress conditions. This study employed ultrasonic surface rolling processing (USRP) to enhance the surface properties of the dual-phase LZ91 alloy. The effects of USRP on surface morphology, microstructure, and hardness were systematically investigated. Results showed that USRP generated a ∼400 μm gradient surface layer. TEM revealed grain refinement to ∼300 nm in both β-Li and α-Mg phases. Surface hardness increased from 52.7 HV to 82.6 HV (56.7% improvement) under identical loading. These findings demonstrate that USRP effectively strengthens the LZ91 alloy by refining grains and forming gradient structures.
PanFSJiangB. Development and application of plastic processing technologies of magnesium alloys [J]. Acta Metall Sin2021; 57: 1362–1379.
2.
ZhangJMiaoJBalasubramaniN, et al.Magnesium research and applications: past, present and future [J]. J Magnes Alloy2023; 11: 3867–3895.
3.
SankaranarayananSGuptaM. Emergence of god’s favorite metallic element: magnesium based materials for engineering and biomedical applications [J]. Mater Today: Proc2021; 39: 311–316.
4.
ChenDDongXZhangX, et al.Mg alloy surface alloying layer fabricated through evaporative pattern casting technology [J]. Trans Nonferrous Met Soc China2010; 20: 2240–2245.
5.
FanCLChenDLLuoAA. Dependence of the distribution of deformation twins on strain amplitudes in an extruded magnesium alloy after cyclic deformation [J]. Mater Sci Eng: A2009; 519: 38–45.
6.
ShiCXLiHDWangDZ, et al.A proposal on accelerating development of metallic magnesium industry in China [J]. Mater Rep2001; 15: 5–6.
7.
SankaranarayananSGuptaM. Emergence of god’s favorite metallic element: magnesium based materials for engineering and biomedical applications [J]. Mater Today: Proc2021; 39: 311–316.
8.
CaiXQiaoYXXuDK, et al.Research progress in mechanical properties strengthening of Mg-Li alloy [J]. Mater Rep2019; 33: 374–379.
9.
YangMPanFChengR, et al.Comparation about efficiency of Al-10Sr and Mg-10Sr master alloys to grain refinement of AZ31 magnesium alloy [J]. J Mater Sci2007; 42: 10074–10079.
10.
GuobingWXiaodongPJunchenL, et al.Structure heredity effect of Mg-10Y master alloy in AZ31 magnesium alloy [J]. Rare Met Mater Eng2013; 42: 2009–2013.
11.
LuiJ-XXieH-TGuoX-G, et al.Superplastic tensile properties and microstructure evolution of dual-phase LZ91 Mg-Li alloy [J]. Chin J Nonferrous Met2022; 32: 713–720.
12.
MehrabiAMahmudiRMiuraH. Superplasticity in a multi-directionally forged Mg–Li–Zn alloy [J]. Mater Sci Eng: A2019; 765: 138274.
13.
WuRYanYWangG, et al.Recent progress in magnesium–lithium alloys[J]. Int Mater Rev2015; 60: 65–100.
14.
YanYDZhangMLXueY, et al.Electrochemical formation of Mg-Li-Ca alloys by codeposition of Mg, Li and Ca from LiCl-KCl-MgCl2-CaCl2 melts [J]. Phys Chem Chem Phys2009; 11: 6148.
15.
PahlavaniMMarzbanradJRahmatabadiD, et al.A comprehensive study on the effect of heat treatment on the fracture behaviors and structural properties of Mg-Li alloys using RSM [J]. Mater Res Exp2019; 6: 076554.
16.
JiHPengXZhangX, et al.Balance of mechanical properties of Mg-8Li-3Al-2Zn-0.5Y alloy by solution and low-temperature aging treatment [J]. J Alloys Compd2019; 791: 655–664.
17.
ZhouWRZhengYFLeeflangMA, et al.Mechanical property, biocorrosion and in vitro biocompatibility evaluations of Mg–Li–(Al)–(RE) alloys for future cardiovascular stent application [J]. Acta Biomater2013; 9: 8488–8498.
18.
YangYPengXWenH, et al.Microstructure and mechanical behavior of Mg–10Li–3Al–2.5Sr alloy [J]. Mater Sci Eng: A2014; 611: 1–8.
19.
LiJHuHWangJ, et al.Improving the microstructure and mechanical properties of ultralight Mg-Li-Zn alloy by multidirectional asymmetric rolling [J]. Mater Today Commun2023; 37: 107266.
20.
LuK. Surface nanocrystallization (SNC) of metallic materials-presentation of the concept behind a new approach [J]. J Mater Sci Technol1999; 15: 193–197.
21.
HeQ-YWuG-LLiuC, et al.Research progress on gradient nanostructured metals prepared by surface nanocrystallization technique[J]. Surf Technol2021; 50: 267–276, 295.
22.
YinMCaiZZhangZ, et al.Effect of ultrasonic surface rolling process on impact-sliding wear behavior of the 690 alloy [J]. Tribol Int2020; 147: 105600.
23.
YouKSongDChengZ-J, et al.Research Status of surface nano-crystallization of metallic materials [J]. Hot Work Technol2016; 45: 15–18, 23.
24.
YangQXuW-WZhouW, et al.Research and progress on surface nanocrystallization of metallic materials [J]. Surf Technol2024; 53: 20–33.
25.
CaiYHuXQuS, et al.Effeet of shot peening on friction and wear properties of CF53 steel[J]. Mater Mech Eng2021; 45: 27–33, 38.
26.
LiX-PKure-ChuS-ZOgasawaraT, et al.Fabrication of a gradient nano-/micro-structured surface layer on an Al–Si casting alloy by means of ultrasonic–electropulsing coupling rolling process[J]. Acta Metall Sin (Engl Lett)2018; 31: 1258–1264.
27.
BagherifardSHickeyDJFintováS, et al.Effects of nanofeatures induced by severe shot peening (SSP) on mechanical, corrosion and cytocompatibility properties of magnesium alloy AZ31[J]. Acta Biomater2018; 66: 93–108.
28.
YeCTelangAGillA, et al. Effects of ultrasonic nanocrystal surface modification on the residual stress, microstructure, and corrosion resistance of 304 stainless steel welds [J]. Metall Mater Trans2018; 49: 972–978.
29.
FengQSheJWuX, et al.The effect of multiple shot peening on the corrosion behavior of Duplex stainless steel[J]. J Mater Eng Perform2018; 27: 1396–1403.
30.
SunQLiuXHanQ, et al.A comparison of AA2024 and AA7150 subjected to ultrasonic shot peening: microstructure, surface segregation and corrosion[J]. Surf Coat Technol2018; 337: 552–560.
31.
ZhaoXZhaoBLiuY, et al.Research on friction and wear behavior of gradient nano-structured 40Cr steel induced by high frequency impacting and rolling[J]. Eng Fail Anal2018; 83: 167–177.
32.
ZhaoJLiangG-XZhangH-Y, et al.Effect of ultrasonic burnished microstructure on the stress-strain behavior of Ti-6Al-4V [J]. Surf Technol2023; 52: 417–424.
33.
MengCZhaoY-CZhangX-Y, et al.Research and application of ultrasonic rolling surface strengthening technology [J]. Surf Technol2022; 51: 179–202.
34.
WangSLiWChenL, et al.Formation mechanism of surface gradient microstructure and mechanical properties evolution of Mg–Y-Nd-Gd-Zr alloy by ultrasonic rolling [J]. J Mater Res Technol2024; 30: 6482–6497.
35.
DangJZhangHAnQ, et al.Surface integrity and wear behavior of 300 M steel subjected to ultrasonic surface rolling process[J]. Surf Coat Technol2021; 421: 127380.
36.
LeiLZhaoQZhaoY, et al.Gradient nanostructure, phase transformation, amorphization and enhanced strength-plasticity synergy of pure titanium manufactured by ultrasonic surface rolling[J]. J Mater Process Technol2022; 299: 117322.
37.
GengJYanZZhangH, et al.Microstructure and mechanical properties of AZ31B magnesium alloy via ultrasonic surface rolling process[J]. Adv Eng Mater2021; 23: 2100076.
38.
ZhouMXuYLiuY, et al.Microstructures and mechanical properties of Mg-15Gd-1Zn-0.4Zr alloys treated by ultrasonic surface rolling process[J]. Mater Sci Eng: A2021; 828: 141881.
39.
JohnMRallsAMDooleySC, et al.Ultrasonic surface rolling process: properties, characterization, and applications[J]. Appl Sci2021; 11: 10986.
40.
WeiZMaBLiL, et al.Effect of ultrasonic rolling pretreatment on corrosion resistance of micro-arc oxidation coating of Mg-alloy[J]. J Chin Soc Corros Protect2021; 41: 117–124.
41.
ChenLLiWSunY, et al.Effect of microstructure evolution on the mechanical properties of a Mg–Y–Nd–Zr alloy with a gradient nanostructure produced via ultrasonic surface rolling processing[J]. J Alloys Compd2022; 923: 166495.
42.
WangTWangDLiuG, et al.40Cr Nano-crystallization by ultrasonic surface rolling extrusion processing[J]. J Mech Eng2009; 45: 177–183.
43.
LiuDLiuDZhangX, et al.Surface nanocrystallization of 17-4 precipitation-hardening stainless steel subjected to ultrasonic surface rolling process[J]. Mater Sci Eng: A2018; 726: 69–81.
44.
TangY-YLiL-BWangC, et al.Research Status of usrp nanocrystallization technology[J]. Surf Technol2021; 50: 160–169.
45.
NiuYSunZ-FSunH-M, et al.Research progress and prospect of the effect of surface nanocrystallization on material properties[J]. Surf Technol2023; 52: 15–30.
46.
MauryaRMittalDBalaniK. Effect of heat-treatment on microstructure, mechanical and tribological properties of Mg-Li-Al based alloy[J]. J Mater Res Technol2020; 9: 4749–4762.
47.
WeiQYangSYuH, et al.Design of high strength Mg-Li dual-phase alloys by synergistic dislocation and grain size control[J]. J Alloys Compd2025; 1016: 178947.
48.
CuiXYangYZhouZ, et al.Developing a lamellar-structured Mg-4Li-3Al-0.4Ca alloy with high strength-ductility synergy[J]. J Mater Sci Technol2025; 229: 116–124.
