Magnesium Alloy Forgings for

Automotive Applications

Mary A Wells

Dean – College of Engineering and Physical

Sciences

Sept 11th , 2018

ACKNOWLEDGEMENTS (PEOPLE)

Guo Yu (MASc student)

Talal Paracha (MASc student)

Massimo DiCiano (Postdoctoral Fellow)

Paresh Prakash (PhD student)

Prof Hamid Jahed

Prof Steve Lambert

THE INCENTIVE OF USING LIGHTWEIGHT

MATERIALS FOR AUTOMOTIVE APPLICATIONS

0

5

10

15

20

25

30

35

40

45

2000 2500 3000 3500 4000 4500 5000 5500

Weight [lb]

Fu

el C

on

su

mp

tio

n [M

PG

]

Premium Small

Entry Small

Midsize

Near Luxury Midsize

Luxury Midsize

Large

Luxury Large

Comp. VAN

Comp. PU.

STD PU

Comp. SUV

Luxury Comp. SUV

Large SUV

CAFE Std. for cars

CAFE Std. for trucks

FITy = -0.006518 x + 48.746

BACKGROUND – MOTIVATION

Cast Al - A356-T6 Benchmark DesignMass: 2.431 kg

Forged Mg - Final DesignMass: 1.534 kg

OPTIMIZED DESIGN WITH 37% WEIGHTREDUCTION

Design validation: The optimized final design of the control arm passes all clearance checking and Ford system-level strength, stiffness and fatigue analysis for the required load cases

THE CHALLENGE FOR WROUGHT MAGNESIUM

BasalRoom Temp.

Prismatic Pyramidal IIPyramidal I

Tensile TwinRoom Temp.

Compression TwinRoom Temp.

• Knowledge base for

magnesium is much

smaller than for steel or

aluminum

• Intrinsically more

complex due to the low

symmetry of the crystal

structure

• Lack of

engineers/scientists with

magnesium knowledge

• Education of the

industry

• Low cost !!

BACKGROUND – APPLICATIONS OF MG ALLOYS

Seat Base - Ford

Intake Manifold - Audi

Friedrich, H., & Mordike, B. (Eds.). (2006). Magnesium Technology – Metallurgy, Design Data, Applications. Berlin: Springer.

FATIGUE STRENGTH AL VERSUS MG

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

100.0

354.0-T6

356.0-T6

359.0-T61

360.0-F

380.0-F

384.0-F

AZ61A-F

AZ80A-F

AZ80A-T5

AZ80A-T6

SpecificFa

gueStrength(MPa-cm

3/g)

Alloy

Aluminum castings

Specific Rotating Bending Fatigue Strength at 108 Cycles

Magnesium forgings

RESEARCH OVERVIEWForging

DesignCorrosion

Residual Stress

Durability

Sensor Embedding

EXPERIMENTAL STRATEGY

Lab Scale

uniaxial

compression

tests

Intermediate

scale forging

using 110 ton

press

Intermediate

scale forging

using 500 ton

press

Forging of

actual control

arm

45 mm

20

mm

10 mm

15

mm

70 mm

63

.5 m

m

17.5 mmUniaxial compression

66 mm110 ton press

85 mm500 ton press

Forging of

actual control

arm

400 mm

1500 Tonne

Press

EXPERIMENTAL STRATEGY

EXPERIMENTAL

MgBillet

Upper Die

Lower Die

Forging

Direction MgBillet

Upper Die

Forging

DirectionMg

Billet

Upper Die

Lower Die

Forging

Direction

Lower Die

Open Die Forging

• Feasibility of forging

selected alloys.

• Forging temperature:

450°C

• Forging Speed: 0.6 mm/s

Semi-Closed Die Forging

• Effect of temperature and

forging speed.

• Forging temp: 250°C-500°C

• Forging Speed: 0.4-40 mm/s

Closed Die Forging

• Effect of pre-form (cast and

extruded) and temperature.

• Forging temp.: 250°C &

375°C

• Forging Speed: 20 mm/s

Full-Scale Forging

• Extruded pre-form (AZ80 and

ZK60).

• Forging temp: 400°C & 450°C

• Forging Speed: 8 mm/s

Lower Die

Mg Billet

Upper Die

Forging

Direction

EXPERIMENTAL

Ø44.0 Billet(Ø63.5)

Ø210.0 Ingot(Ø304.8)

Extruded Mg Cast Mg

Extrusion

Axis

Orientations and Locations of Ø10mm x 15mm Compression Samples

CastingDirection

FLOW STRESS MEASUREMENTS (EXTRUDED AZ80)

FLOW STRESS MEASUREMENTS (AS-CAST AZ80)

110 TON PRESS AT CANMET

110 TONNE PRESS AT CANMET

SIMULATION WITH DEFORM 3D

400°C, 0.4mm/s

500 TON PRESS AT CANMET

17

0.06mm/s

0.6mm/s

6mm/s

FORGING VIDEO (500 TON PRESS AZ80)400°C, 0.6 MM/S

500 TON PRESS EXPERIMENTS

TD

ED

0.067mm/s 0.667mm/s 6.667mm/s

SAMPLE EXTRACTION

(MECHANICAL PROPERTY MEASUREMENTS)

12 mm

4 mm

6 mm60 mm

FD: Forging Direction LD: Longitudinal Direction RD: Radial Direction

Figure 1: I-Beam forging side view.

LD

RD

FD

Figure 3: Specimen

Geometry

1

2

3

11

12

13

14

15

6

7

8910

5

4

RD

FD

LD

Web: B Tall Flange: CShort Flange: A

S-N CHARACTERIZATION (AZ80)

130

140

150

160

170

180

190

100 1,000 10,000 100,000 1,000,000

Stre

ss A

mp

litu

de

[MPa

]

Number of Cycles [N]

As-Ext (ED)

As-Cast (LD)

250°C (IF41)

250°C (IF44)

275°C (IF38)

375°C (IF59)

375°C (IF62)

Cast ExtForged Forged

FORGING OF CONTROL ARMS (1500 TON PRESS)

Flattening Operation

Forging Operation

FORGING OF CONTROL ARMS (1500 TON PRESS)

FORGING OF CONTROL ARMS (1500 TON PRESS)

Flattening Operation

Forging Operation

CONTROL ARM COMPARISON SIMULATION TO

MEASUREMENT

SUMMARY

• Magnesium alloy AZ31, AZ80 and ZK60

were successfully forged under a range of

conditions

• Starting structure has a large effect on

microstructure evolution and processing

map

• Anisotropic DEFORM 3D model able to

capture flow behavior and load during

forging

ACKNOWLEDGEMENTS

Automotive Partnership Canada