Research Activities on Magnesium Alloys in Korea
Kwang Seon Shin
Chairman, Korea Magnesium Technology Research Association
Professor and Director

Magnesium Technology Innovation Center
School of Materials Science and Engineering
Seoul National University, Seoul 08826, Korea

Content Introduction
 Research Activity at Magnesium Technology

Innovation Center, Seoul National University

 WPM Magnesium Project Development of Corrosion Resistant Nonflammable

Mg Alloys at KIMS

Magnesium

マグネシウム镁마그네슘Magnesium

Magnesioмагнезия

Magnesium Crown Formed in the Pidgeon Process

Magnesium Consumption by Application
Iron
Nodulizing
Steel
Desulphuri- 65kt, 6%zation
123kt, 11%

Other60kt, 5%

Titanium
Refining
119kt, 11%
Die Castings,364kt , 33%

Aluminum
Alloys367kt, 33%

2012367364123
11965
60
1,098

Al Alloys
Die Casting
Ti Refining
Steel Desul.
Iron Noduli.
OtherTotal
IronSteelNodulizing
Desulphuri- 79 kt, 6%zation
148 kt, 10%2017468499
136
148
79
70
1,400

Other
70 kt, 5%

CAGR(%)
5.0
6.5
2.0
4.5
4.0
3.5
5.0
Aluminum
Alloys468 kt, 33%

Titanium
Refining
136 kt , 10%
Die Castings
499 kt, 36%

Magnesium Metal 2013, Roskill
KMTRA

Magnesium Consumption by Country (2012)(Unit: kt, %)Actual Consumption inSouth Korea : 35kt

Others284.02kt
26%

Norway18.5kt, 2%

China
342.51kt
31%

South Korea
24kt, 2%

Kazakhstan
20.42kt
2%
Brazil28.16kt, 2%Japan
52.61kt
5%

Canada Germany
41.96kt 12kt, 1%
4%

Russia76.48kt
7%

USA
196.24kt
18%

Global Total : 1,096.9kt
Magnesium Metal 2013, Roskill
KMTRA

Prospect of World Demand of Primary Mg Ingot (2020)

Cathodic Protection 40kt

Nodulizing
30kt

Wrought Products
49.6ktOthers
10kt

Titanium Sponge
106kt

Castings
683.4kt

Desulphurization237kt

Al Alloys
529kt

Global Total : 1,685kt
Korea Magnesium Industry 2013, KMTRA

Magnesium Consumption in Korea

Pure Mg

Mg Alloys

Other (billet, bar, granule, chip)POSCO Mg Business Overview
Mg Extracting Plant(Gangneung)

POSCO Center(Seoul)

Completed Constructionof Mg Extracting Plant

Pohang WorksFeSi Plant
Mg Strip Plant(Suncheon)

Gwangyang
Works

Proposal andConsultingfor Mg
Business

Started Constructionof Mg Extracting Plant

Completed #1 Plant (600mm)
Construction
Started Construction ofMg Sheet Plant

Succeeded in Production of0.4mm Mg Sheet
Succeeded in Mg Twin Roll Casting at
Pilot Plant
Started R&D on Twin Roll Casting
Process
Executed Business Feasibility
Research2002

2003

2004

2005

2006

2007200820092010

2011

20122013

2014

2015

POSCO Twin Roll Cast 2,000mm Magnesium SheetPOSCO Twin Roll Cast 2,000mm Magnesium SheetApplication of POSCO Mg Sheet to Automotive Body
 Renault 1Liter Sep. 2014, SM7

Concept Car
EOLAB (Seoul
Motor Show, April2015)
 Roof of Vehicle
 Steel 10kg  4.5kg
Reduction
 Total 130kg
LightweightNova : POSCO Mg
Plate to Luggage
Retainer World First
Application ofPOSCO Mg Plate toCommercial Vehicle
 Luggage Retainer :61% Lightweight Steel (3.6kg) → Mg
Sheet (1.4kg)
 Porsche 911 GT3 RS Roof (GenevaMotor Show, March 2015) Lower Center of Total Vehicle’sMass
 Increase Safety Handling of Vehicle

High Performance Magnesium Alloys
 Low Cost
 High Formability
 Corrosion Resistance High Strength Nonflammability
 Isotropic Mechanical Properties
 Low Density
 High Modulus
 ….......

Research Activities at Magnesium Technology Innovation Center Development of Advanced Mg Alloys

 Computer Simulation of Stable Phase Formation and Flow/SolidificationBehavior by Thermodynamic Calculations
 High Strength/High Formability Alloys
 High Temperature Alloys
 Corrosion Resistant Alloys and Biomaterials

 Characterization of Microstructure/Texture and MechanicalProperties
 Prediction of Deformation Behavior by VPSC-GA Simulation
 Analysis of Microstructure/Texture, Dislocation, Twin
 Manufacturing and Characterization of Mg Single Crystal
 Mechanical and Corrosion Behavior
 Characterization of Creep and Fatigue Properties
 Development of Strip Casting/Extrusion/Rolling Processes Semi-Solid Processing of Mg Alloys
 Surface Treatment: Plasma Electrolytic Oxidation Coating
 Development of Mg Die Casting Components for Automobile andElectronic Industries

Development of High Strength
Magnesium Sheet with High Formability

Twin Roll Casting Process

 Advantages
 Low Production Cost
 Fine Grain Size

 Casting Defects
 Centerline and Inverse Segregation

 Inclusion and Porosity Surface Cracking and Oxidation
 Sticking-related Defects

Schematic Diagram of Twin Roll Casting

M. Ferry, Direct Strip Casting of Metals and Alloys, Cambridge, UK, 2006

Solidification Behavior & Segregation
AZ31

Increasing Roll Speed: Increasing Exit Temp.
 Factors Affecting SolidificationBehavior

 Freezing Range of Alloys
 Thermal Properties of Alloys
 Roll Speed

 Roll Separating Force Melt Temperature Setback Distance Development of New Mg

Alloys for TRC Process Optimization of Processing
Parameters

P. Thomas, Continuous Casting of Aluminium Alloys, Institute of Physic, 2003, UK, 26-47

Manufacturing Process for TRC Plates Fabrication of TRSC Mg-6Al-0.3X Plates Thickness: 3.0~3.3mm
 Width: 50~65mm
 Development of New TRC Mg Alloys with Low Segregation & Improved

Formability

Simulation of Liquid Fraction During TRC ProcessLiquidFraction

A6RollDistance

Distance toRoll Nip Point
A6: 64.6mm

AX60

AX60: 48.9mm
AC60

AC60: 49.1mm
AS60

AS60: 36.8mm
AJ60

AJ60: 58.2mm
AZ60

AZ60: 34.6mm

Microstructure of TRC Mg-6Al-0.3X Alloys
CDA6AX60(0.3)

AC60

ND

 Segregation Factors

 Freezing Range
 Second Phase Solidification Behavior
 Partition Coefficient

Segregation

Segregation

Segregation

AS60

Segregation

AZ60

AJ60

Segregation

Segregation

Mg Alloys
A6AX60
AC60
AS60
AJ60
AZ60

Centerline
Segregation %1.92.1
2.0
2.72.23.4Centerline Segregation Area and Melt to Roll Nip DistanceCenterline Segregation Area (%)

5432A6
AX60
AC60
AS60
AJ60
AZ60

1010305070

Melt to Roll Nip Distance (mm)90Samples of Mg-6Al-X Alloys after Erichsen Tests
Pre-heating: 350oC

Pre-heating: 450oC
A6: 3.3mm

A6: 4.8mm

AX60: 3.4mm

AX60: 5.3mm

AC60: 3.5mm

AC60: 5.1mm

AS60: 3.3mm

AS60: 6.4mm

AJ60: 3.4mm

AJ60: 5.7mm

AZ60: 3.4mm

AZ60: 5.2mm

Procedure for VPSC-GA Simulation<VPSC>

Initial Texture

Uniaxial TensionUniaxial Compression

Strain Hardening &Twin Reorientation
Parameters
Execution of
VPSC Simulation
Comparison ofStress-Strain Curve<GA>

Range of
Hardening Parameters(Input Parameters)
Generation of
Candidate Solutions(Mating Process)
Crossover & Mutation ofSolutions

Comparison ofDeformation Texture

Selection of Fitter Solutions

Are They Similar
to Exp. Results?

Calculation of
Fitness

Yes(Deformation Mechanism)
Activity
Strain Hardening Behavior

Activities of Deformation Modes (Pre-heating: 350oC for Rolling)Tension(Modes)Basal <a>Prism. <a><c+a>Tensile Twin
CompressiveTwin(Alloy)A6AX60AC60
AS60
AJ60AZ60

Relative Acitivity

0.8
0.6
0.4
0.2
0.00.00

0.05

0.10

0.15

0.20

|True Strain|

0.25

0.30

1.0Compression(Modes)Basal <a>Prism. <a><c+a>Tensile Twin
CompressiveTwin(Alloy)
A6
AX60
AC60
AS60
AJ60
AZ60

0.8

Relative Acitivity

1.0

0.6
0.4
0.2
0.0
0.00

0.05

0.10

0.15

0.20

|True Strain|

0.25

 Deformation Modes Tension: Initially Basal <a> Slip & Later Prismatic <a> Slip Activated Compression: Mainly Basal <a> Slip & Tensile Twin Activated0.30

Activities of Deformation Modes (Pre-heating: 450oC for Rolling)Tension(Modes)Basal <a>Prism. <a><c+a>Tensile Twin
CompressiveTwin(Alloy)A6AX60
AC60
AS60
AJ60
AZ60

Relative Acitivity

0.8
0.6
0.4
0.2
0.0
0.00

0.05

0.10

0.15

0.20

|True Strain|

0.25

0.30

1.0Compression(Modes)Basal <a>Prism. <a><c+a>Tensile Twin
Compressive
Twin(Alloy)A6AX60
AC60
AS60
AJ60
AZ60

0.8

Relative Acitivity

1.0

0.6
0.4
0.2
0.0
0.00

0.05

0.10

0.15

0.20

|True Strain|

0.25

 Deformation Modes Tension: Significant Increase in Activities of Basal and <c+a> Slip
 Compression: Mainly Basal <a> Slip & Tensile Twin Activated0.30

Conclusions
 Thermodynamic Properties
 AZ60 alloy has the largest solidification range.

 Simulation Results of TRSC Process AS60 and AZ60 show high segregation tendency.

 Centerline Segregation Tendency
 AZ60>AS60>AJ60>AX60>AC60>A6

 Mechanical Properties and Formability AX60 and AJ60 show good combination of tensile properties andErichsen values with weaker basal texture.

 Effects of Rolling Condition on Texture and Formability
 Increase in Pre-heating Temp.: Decrease in Max. Intensity of (0002) andSignificant Increase in Erichsen Values.

 Deformation Mode Increase in Pre-heating Temp.: Increase in Activity of Non-Basal Slip There exist some relationships between Erichsen value and CRSS ratio.

WPM (World Premier Material) Project
PurposeR&D Project for 10 world best materials

Characteristics

Long-term (2010~2019), New market creating

Philosophy

Company-led, Break through, Open innovation

10 WPM Projects(World Premier Material)

Smart
CoatingSteelMg

NanoComplexHigh
MolecularMembrane

Flexible
DisplaySecondaryBattery…

27 / 26

WPM Mg Project+ Mg material R&D project for the super-light vehicle•

Improving the technology level on alloy & application Tech. from initial basic study to commercialization

New alloy development
Forming of automobile part

21 organizations
involved

Surface treatment & joining+ Project group
Main Project(led by POSCO)• 21 Organizations:- Company (15)- Research institute (3)- University (3)• Budget: $ 58.9 million (USD)

Mg sheet• Development for Mg sheet technology• Company(13) / Research institute(3) / University(3)Mg bulk• Development for Mg advanced casting technology• Company(2) / Research institute(1)28 / 26

Technology Development Strategy+ Mg Sheet Material with High Properties Specialized in Vehicle Development
New Alloy(for strip cast)High Perform.
Extracting

Coil Making

Forming, Welding
Surface Treatment
HoodDoor

Sheet Forming
Thermal Analysis
Strip Caster
Surface Treatment

Thermal Reduction
Furnace
Texture Analysis

RWM(Reversible WarmRolling Mill)

Welding

29 / 26

WPM Mg Project System+ 21 Organizations for the project
3 Research Institutes
3 Universities

WPM MgProject

10 Suppliers

5 Customers

30 / 26

Technology Development Structure
Mg Plate
Feed-backNew Alloy

Mg Smelting

Mg Sheet
ProductApplication
Forming

Welding

Surface Treatment

Performance Evaluation& Feed-back

31 / 26

Principal Results (Sheet Technology)

Cross Car BeamForming

Mg Sheet

Hood Ass`yDevelopment of wide strip casting & rolling
technology
Mold of Roof

Surface
Treatment

Ingot

Alloy
DesignRecycling & Alloying

Alloy

YS (MPa)UTS (MPa) Er. (mm)

AX607

212.2

305.6

7.0

AX61

216.2

307.0

7.5

AZ62

219.8

336.9

6.6

32 / 26

Seoul National University & POSTECH+ New Alloy: Sheet
Development of new alloy with high strength & formability- Analysis of plastic deformation behavior and texture- Analysis of recrystallization behavior
1.0

Tension(Modes)Basal <a>Prism. <a><c+a>Tensile Twin
Compressive Twin
(Material)
AMX610
AMTX6110AMTCX61100
AMTE(Nd)X61100
AMTE(RE)X61100
AMTSX61100
AMTJX61100

Relative Acitivity

0.8
0.6
0.4
0.2
0.0
0.00

0.05

0.10

0.15

0.20

|True Strain|

Rolling(7.167)

0.30

40%

TD

μm
Compression(Modes)Basal <a>Prism. <a><c+a>Tensile Twin
Compressive Twin
(Material)
AMX610
AMTX6110AMTCX61100
AMTE(Nd)X61100
AMTE(RE)X61100
AMTSX61100
AMTJX61100

0.8

Relative Acitivity(0002) Pole Figure

RD

1.0

0.6
0.4
0.2
0.0
0.00

0.25

Casting(TRSC)

0.05

0.10

0.15

0.20

|True Strain|

0.25

RollingNDRD

Annealing(6.891)

Study on the change of microstructure and texture

0.30

Alloy design optimization using VPSC computer simulation

33 / 26

POSCO+ Wide sheet casting & rolling
Development of rolling technology- Width: casted coil 2,000mm, rolled coil 1,270mm

EOLAB roof & dash panel- Thickness: 6mm ~ 0.15mm

Commercialization to the development of a wide sheet and thin plateGT3 RS roof

Korando C Speaker cone

Development of Rolling & after-treatment technology

수모델 PIV 촬영 – 레이저 투입Continuous rolling process of width 2,000mm casted coil
34 / 26

POSCO+ Sheet casting & rolling (E-form®)
300

Stress (MPa)250

LDH = 7mm

200

High strength & ductility

150
100
50
00

0.05

0.1

0.15

0.2

strain: low fraction of center segregation, high fraction of twins, weak texture: distributed thermally stable particles

35 / 26

SUGNWOO HITECH+ Development of car body partDevelopment of stamping technology- Warm forming die design, HemmingDevelopment of car body parts- Reinforcement center floor, Hood assembly

Reinforcement center floor

HoodOptimum design

Prototype manufacturing

Development of hemming process
36 / 26

AUSTEM+ Development of car body partDevelopment of stamping technology- Optimization of mold design

Development of car body parts- Rear seat back frame, Cross car beam

Rear seat back frame

Cross car beam

Optimum design

Prototype manufacturing
37 / 26

RIST & KITECH+ Joining
Development of joining Technology- Evaluation of weld zone: Dynamic Properties, Strength, etc.

 Spot welding- Dome type electrode(+)- Radius type electrode(-)

(+)

(-)

8

<Electrode life time: 20(welds)><Electrode life time: 80(welds)>

61616R Laser welding CMT welding- YS:188MPa- TS: 270MPa- El: 5.3%

- YS:177MPa- TS: 252MPa- El: 8.5%

※ Bare metal YS:220MPa TS: 280MPa El: 12%

 FSW welding- YS: 132MPa- TS: 228MPa- El: 2.8

 MIG welding- YS: 178MPa- TS: 231MPa- El: 3.1%
38 / 26

RIST & Noroo Coil Coatings & KC Chemical+ Surface Treatment
Development of surface treatment- Development of chemical conversion coating process- Development of plasma electrolytic oxidation

 Improvement of coating quality by new pretreatment
TOPSIDETOP Comparison with various surface treatment- Plasma electrolyticoxidation (PEO)- Chemical conversiontreatment

TOPSIDESIDE- Heat treatment with humidity (under study)
5.16μm

HH Layer

30 μm<Cross cut test><Cross cut test><Cycle corrosion test 10 Cycle><SST 600hr><Cross cut test><SST 720hr> 39 / 26

Commercialization
Commercialization: Mg Luggage retainer

Commercialization: Mg Roof, Dash panel

Renault Samsung Motors New SM7

Renault EOLABWeight

Weight reduction- steel: 3.6 kg- roof: 55%- Mg: 1.4 kg- dash lower: 60%<Mg roof><Mg dash lower>

40 / 26

Corrosion ResistantNon-flammable Alloys(SEN alloy)

Korea Institute of Materials Science (KIMS)
Aluminum/Magnesium Department

Synergy Effect of Ca and Y Addition

Aluminum/Magnesium Department

Non-flammability
New non-flammable alloys
900

Ignition Temperature, C

In the atmosphere
Furnace temp.: 1000C

0.1g chip800

MgO + MgAl2O4 + CaO

700

CaO + Y2O3Tm (pure Mg)

YCa600

Y500

Y Ca
400

AlMg YCaAlMg

YCaMg

YMg

YYYCaYMg

Al“Multi-layeredstructure”

YMelt< Non-flammability mechanism of AZ-Ca-Y alloys>
Commercial alloys Ca-addedAlloys

CaO-addedAlloys

KIMS Alloys(a) Provided by KITECH (Source: Magnesium Alloys - Design, Processing and Properties)(b) Measured by KIMS using the ingot produced by HMK

Aluminum/Magnesium Department

New Non-flammable Alloys

UTSProperties,
x El., MPa%MPa%
Mechanical

11000

9000

New alloys(Ca, Y added alloys)

7000

Commercialalloys

5000

Conventional Caadded alloys

3000
400500600

700800900Ignition Temperature, C

Aluminum/Magnesium Department

Oxidation Behavior<SEN-9 : AZ91-0.3Ca-0.1Y>
Aluminum/Magnesium Department

Corrosion Behavior

ALDCSEN-9

AZ91D
Aluminum/Magnesium Department

Corrosion Behavior(a) AZ91D(b) SEN-9(c) ALDC

<SEN-9 : AZ91-0.3Ca-0.1Y, ALDC : Al-11Si-2.5Cu>
Aluminum/Magnesium Department

Die-castingAluminum/Magnesium Department

Al/Mg profiles for extrusion
Roof Panel

Aluminum

Magnesium

Side Panel
Weight Saving
25.8%

Under Frame

Upper skin

Rib
Vertical rib

Lower skin

Upper skin

Vertical rib
RibLower skin

Aluminum/Magnesium Department

GM Door Inner Panel (Die cast)Benefits Reduced part count Fewer manufacturing steps
 50% less embodied energy 50% less weight Improved fuel economy

Steel stamped- 다수부품의 용접/다단계 공정

Magnesium stamped- 단일부품의 die castingAluminum/Magnesium Department

FAA Test & Mg Seat Frame
FAA Test

Aluminum/Magnesium Department

Mg Extrusion ; Seat Frame

Aluminum/Magnesium Department

Summary Development of High Strength Magnesium Alloys with HighFormability at Magnesium Technology Innovation Center at SNU
 WPM Magnesium Project TRC Mg Sheet with 2,000mm Width Forming, Joining, and Surface Treatment Technology
 Applications: Hood, Retainer Development of Non-flammable Mg Alloys at KIMS

The Magnesium Age