SPS

The 1st Russia-Japan SPS Workshop Moscow, Russia May 20-22, 2013

(SPS: Spark Plasma Sintering)

Recent Advanced Spark Plasma Sintering (SPS) Technology , Systems and Applications in Japan

Masao TOKITA SPS R&D Center

NJS Co.,Ltd Japan

CONTENTS

Introduction of Recent SPS Technology

Demands from Industries on SPS

Advanced SPS Systems

Large Scale Ceramics by SPS

Outlook & Summary

Lockheed Co.(USA) bought the patent in 1968

Kanagawa Science Park (KSP) and ex. JAPAX INC building at left

The 1 st Generation SPS

SPS Technology was originally born in Japan

Right : Dr. K.Inoue (The first SPS Inventor/president of JAPAX)

Left : Mr. K.Okazaki (The first president of JAPAX INC.)

Russia - Japan

( U.S.S.R )

Dr. B.R. Lazarenko & Dr. N. I. Lazarenko of U.S.S.R. in 1943

EDM invented in Russia by Dr. Lazarenko EDM also invented in Japan by Dr. K. Inoue Electrical Discharge Machine ( Electrospark Machining )

Founder of EDM Technology

Wire-Cut EDM

Ram-type EDM

Spark Sintering

ECM ECG

ECB ECDM SPS :

Spark Plasma Sintering

Spark Forming

Progress of SPS Technology

Nano, Porous,Thin film

Reaction, Synthesis

Composite

Ultra-Vacuum

SPS Chemistry

Kinetic Window

Electro-migration

Re

se

arc

h &

D

eve

lopm

ent

Rapid High-density

Homogeneity

Fine micro-structure

Low temperature

Amorphous

Increasing Use of SPS Technology in Japan

0

5

10

15

20

25

30

35

40

45

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007

Powder & Powder Metlgy. Spring

Powder & Powder Metlgy. Autumn

Ceramics Japan Spring

Ceramics Japan Autumn

Japan Inst.Metals Spring

Japan Inst.Metals Autumn

Nu

mb

er

of

Pre

se

nta

tio

ns

Number of presentations on the SPS introduced at major advanced

materials conferences from 1990 to 2007

Private Enterprise 0

50

100

150

200

250

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

/Mar

ch

As of 2010, more than 550 units of SPS machine systems installed in total

in 2005

Figure 3. Increasing use of the SPS machines in the world SPS units produced & installed 1990-2010

SPS Job-shop center in Japan (left/3MN right/200KN) 300mm large Al2O3 SPSed compact(Relative density:98%)

Advanced Ceramics Handbook 2nd Edition

American Ceramics Society, Published in 2013, Chapter 11.2.3 SPS

Increasing Use of SPS Technology

2012(estimated)

SPS TOTAL:

650-700 units

Manufacturers:

14 Companies

In the World

Max Planck Institute,

Dresden, Germany

International

Workshop on Spark

Plasma Sintering October 6-7, 2008

Le Petit Louvre Avignon France

APFNM2008

International Congress Center

Dresden, Germany

23 25 January, 2008

IP-NANOKER LARGE CERAMICS Workshop Thales Alenia Space, Cannes, France February 21st, 2008

PacRim7 held in Shanghai, China 11-14 Nov. 2007 SPS session Spark Plasma Sintering Synthesis and Processing of Materials

2010-2012 Pulse Energizing Processes(SPS)

2011 Autumn SERVO METAL FORUM

2012 Winter

SERVO METALRORUM

2010 July SPS BOOK 28Papers/8Chapters

Total343 Pages Authors28 Publisher:[TIC Inc.

Materials Integration(TIC Inc. 2010, July/Aug/Oct/Nov SPS Special Edition

Annual Symposium SPS FORUM of Japan 201/ November 16th in Sendai, Tohoku University

2012 / June STAC-6 Int. Sympo (Yokohama) SPS Special Session

2012 / October PM2012 Int. Congress (Yokohama) SPS Special Session

2012 / December 17th SPS FORUM of Japan, Tohoku University

Recent SPS Activities in Japan

Sintering

Sinter-Bonding & Joining

Surface Treatment

Synthesis Nano-Phase

Materials

Thermo-Electric

Materials

Bio-Materials

Functionally Graded

Materials (FGMs)

Versatile Process & Large Number

of Potential Applications

Advanced Ceramic

Materials

and others

Pure Nano SiC (30nm 100nm)

R.D : 99.4%

mHV : 2380

Transparent ceramics

Suitable materials for SPS processing

Oxides

Carbides

Nitrides

Borides

Flourides

Classification Materials for SPS processing

Cr, Mo, Sn, Ti, W, Be

SiC, B4C, TaC, TiC, WC, ZrC, VC

Metals

Fe, Cu, Al, Au, Ag, Ni Virtually any metals possible

Ceramics

Al2O3, Mulite, ZrO2, MgO, SiO2, TiO2, HfO2

TiB2, HfB2, LaB6, ZrB2, VB2

LiF, CaF2, MgF2

Si3N4, TaN, TiN, AlN, ZrN, VN

NbCo, NbAl, LaBaCuSO4, Sm2Co17

Organic materials (polyimide, etc.), compositematerialsOther materials

SUS+WC/Co, BN+Fe, WC+Co+Fe

Intermetaliccompounds

TiAl, MoSi2, Si3Zr5, NiAl

Cermets

Si3N4+Ni, Al2O3+Ni, ZrO2+Ni

Al2O3+TiC, SUS+ZrO2, Al2O3+SUS

Classification of Spark Plasma Systems (Processes) Four Different Processing Categories can be covered by SPS techniques

Recent Demands for SPS form Industries

Fully Automated Machine Systems

More Complex Shape Product

Higher Functionality

Hybrid materials

Thinner materials

Finer & Smaller Sized Products

Nano-crystalline materials

Finer micro structural materials

Porous materials

Higher Reliability & Safety

High Value Added Products

Multi-use, Small-Medium scale Production

Highly Dense materials

Highly Homogeneous materials

High Reproducibility ( Repeatability )

Larger Sized Products

Thicker materials

Single Crystal materials

General Purpose Sintered Products

Manual type Simple &

Low cost machine systems

SPS

EX) 10 K 30 K(70K~100K) pieces/month

General purpose Mass, Large scale Production

Composite materials

3-D Near-Net/Net shape Forming

SPS system configuration

Basic mechanism of neck formation by spark plasma When a spark discharge occurs in a gap or at the contact point between the particles of a material, a

local high temperature-state (discharge column) of several to ten thousands of degrees centigrade is

generated momentarily. This causes evaporation and melting on the surface of powder particles in

the SPS process, and necks are formed around the area of contact between the particles.

Does Spark Discharge Occur in Powder Particles?

Does Spark Plasma Occur during SPS Energizing?

Collateral Evidence Examples of SPS Effects

AlO

Ni Atomized cast iron

SPS

Normal Sintering

(in Vacuum)

SiC Fiber

PROCESSING

(SOFTWARE)

SYSTEM

(HARDWARE)

POWDER

MATERIALS

Concept of SPS technology development = Trinity system of

Hardware, Software and Powder Materials

Basic R & D Process using SPS

Example of Nano-Al2O3 by SPS

XRD patterns of -Al2O3 prepared at 11731473K under 49 MPa

Powder materials used -Al2O3Average particle size 37nm(Nanotek,Inc. -Al2O3particle size 0.5Sumitomo Chemicals co.Ltd) -Al2O3particle size 0.2 Taimei Kasei Co.,Ltd) SPS apparatusSPS511S,SPS2040 (Sumitomo Coal Mining Co.,Ltd.)

1473K

Change of density as a function of temperature under 49MPa

Sinterability and Phase transformation

SPS Conditions Sintering Temp.873K-1773K Holding time : 0-600sec. SPS pressure : 49MPa, Pa Vacuum R.D.98% Theoretical Density: -Al2O3 3.67g/cm

3

3.98 3.65 :3.58

, -Al2O3 were densified more than R.D98% at 1773K. -Al2O3 phase change to -phase at 1473K

49MPa

Change of density as a function of temperature at 690MPa

SEM micrograph of -Al2O3 and -Al2O3 (0.2m,0.5m)

prepared at 1773K under

49 MPa for 60s.

FE-SEM micrograph of -

Al2O3 prepared at 973~1173K

under 690 MPa

80nm

150-300nm

300-600nm

R.D98%

R.D85%

Density decreased due to -phase change to and -phase

R.D79%

690 MPa

XRD patterns of

-Al2O3 prepared

a 9731173K under

690 MPa

-Al2O3 prepared by

-Phase transformation occurred at 1173K under pressure of 690MPa . Approx.300K lower than 49MPa of 1473K.

Grain growth was minimized

Pressure Effects in SPS MPa Vs MPa Phase and Grain Growth Behavior

- -Al2O3 ,, 690 MPa

nm 1773K,49MPa

SiC Mechanical properties Comparison on SPS vs HP sintered compact

Dependence of relative density on the sintering

temperature in the SPS- and HP-consolidated SiCs

Dependence of Vickers hardness on the sintering

temperature in the SPS- and HP-consolidated SiCs

Dependence of bending strength on the sintering

temperature in the SPS- and HP-consolidated SiCs

Relation between fracture toughness and bending

strength in the SPS- and HP-consolidated SiCs

Starting powder

-SiC:average particle size 0.28m

5%-Al2O3:0.22m

3 Yb2O3:0.4m

SPS apparatus

SPSMk-IV

Sumitomo coal Mining Co.,Ltd

Hot press

Fuji Denpa Ltd.)

SPS:100K/min

HP:70K/min

SPS sintering condition Pressure MPa keeping time min.

SPS

HP

SPS

HP

HP

SPS

R.D 98%

approx.200K lower temperature

2123K

2073K

2023K

SPSed specimen

showed higher

mechanical

properties than

HPed one

Bending strength Fracture toughness and Bending Strength

Hardness Density

From XRD and Raman scattering analysis, it is suggested that disordered cubic structure (C-type) of SiC can be preserved in the SPS consolidation, and the scarce detection of Yb3Al5O12 phase suggests the existence of oxide additives in amorphous-like state.

XRD patterns obtained from raw powder, SPS- and HP- SiCs

Raman scattering spectra obtained from

raw powder, SPS- and HP-consolidated SiCs

1 m

m

1m

m

SPS/ 2073K 30MPa HP 2273K 30MPa

SPS sintered compact shows larger grain size than HP compact, however the bending strength and fracture toughness are higher than HP sintered compact. SPS can improve those mechanical properties. Grain boundary of crystallographic behavior is different

SiC

By Prof. Munir etal. Of California University

SPS Technology Topics Especially from overseas SPS researchers

One of the distinctive phenomenon of SPS is Kinetic Window. There is an obvious difference in powder particle size 100-200nm and under 50nm (20-30nm). Rapid grain growth occurs in a few dozen degrees of sintering temperature difference. Stockholm Univ. /Prof. M. Nygren, ( NJS/Dr.M.Tokita ) Actual temp. difference in sintering temp. measurement seems significant, but not so practical. Max-Plank-Institut /Dr. Y. Grin Stockholm Univ. /Prof. Nygren , ( NJS/Dr.M.Tokita )

SPS is recognized as a Reaction Synthesis (Sintering) Need New Concept. CNRS/Dr.J.Galy, Univ. of Burgundy / Prof. F. Bernard Univ. of California-Davis / Prof. Z.A. Munir

Max-Plank-Institut /Dr. Y. Grin, ( NJS/Dr.M.Tokita ) Stockholm Univ. /Prof. M. Nygren

Continuous researches on differences between AC/DC and also relation between Heating Rate, Densification, Grain Growth and Pulse Energizing Effect. Univ. of California-Davis, Wuhan Univ. of Technology

Univ. of Burgundy Stockholm Univ. etc. ( NJS/Dr.M.Tokita )

SPS is most effective Sintering & Synthesis Method for Nano/Nano-Composite Materials. Shanghai Institute of / Prof. L. Chen Tsing Hua Univ. etc. ( NJS/Dr.M.Tokita ) Many other researchers from every country

Wave Form of Thyristor-type SPS Pulse Generator (patented) < developed, manufactured and measured by Sumitomo/SPSS since 1989 >

ON-Time setting: 1 (3.3ms) ON-Time setting: 99 (326.7ms) OFF-Time setting: 1 (3.3ms) OFF-Time setting: 9 (29.7ms)

ON-Time setting: 12 (39.6ms) OFF-Time setting: 2 (6.6ms)

Wave Form of Inverter-type SPS Pulse Generator (developed, manufactured and measured by Sumitomo/SPSS in 1996-98)

ON-time: 10ms OFF-time: 30ms ON-time: 30ms OFF-time: 10ms

ON-time: 90ms OFF-time: 10ms

IGBT/PWM Control system

Different type of SPS machine systems Developed in Japan

[] Multi Head System [] Batch System [] Tunnel type System [] Rotary-type System [] Shuttle-type System

Full Automatic SPS System (Tunnel-type)

SPS JOB-SHOP in Japan

Batch-type System Max. sintering pressure: 3 MN

Max. DC pulsed current: 30,000A

Max. sintering pressure:200 KN

Max. DC pulsed current: 8,000A

mm

Max.MPa

Disk-shape 300-350mm in diameter of metallic sputtering target fabricated by SPS

01234

56789

SPS HP/HIP

Time

Comparison of sintering time

between SPS and HP/HIP methods

SPS Sintering Temperature: 13731473K

Relative Density: 99100%

Example of Large-sized Product in Materials Industry

Other examples) CrB2, CrB, SiC, SiO2, Ta2O5, ITO

BaTiO3, PbTiO3, TiN, TiAl, Ti-Al-Si

Mg2Si, Ru, RuCo, NiCr, Ti-Ta

WC/Co Diamond Cutting Blade by SPS

Sintering Powder Material (or Green body)

Outer Diameter 100/150mm

Inner Diameter 40/60mm

Thickness 0.35/0.4mm

SPS sintering temp. 1473 1523K

Sintering Pressure 40 50MPa

Relative Density 99 100%

Young Modules 500 580GPa

Flatness

Three sets of Batch-type Large sized SPS manufacturing systems

working at the same companys Production factory in Japan

No3. Installed in 2005

No2. Installed in 2004

20 hours / day by 2 shifts

24 hours / day by 3 shifts

Max. Sintering Pressure : 1000-2000KN

Max. DC Pulse Current : 15,000-20,000A

No1. Installed in 2003

Hybrid System - Tunnel-type Automatic SPS

Manufacturing systems

Inlet

Vacuum Exhaust

Pre-Heating

SPS Sintering

Cooling-1

Cooling-2 /Air Introduction

Outlet

Developed & Installed in 2001

FGM by SPS system

5-Chamber system

100mm70mm10mm Large-size WC/Co cemented carbide hard-alloy compacts automatically-fabricated by the SINTER-EXPERT system

Co Content Grain Size Density Hardness

Transverse

Rupture

Strength

Fracture

Toughness

(wt%) (m) (g/cm3) (mHv) (Kg/mm

2) (K1C)

TC10 < 4 < 0.5 15 2150 270 6.5

TC20 < 6 < 0.5 14.8 2050 300 7.3

M78 0 < 0.2 15.4 2600 150 5

Product

Cord Name

Typical mechanical properties of WC/Co tungsten carbide hard alloys sintered by SPS

SPS sintered compact Vickers hardness distribution behavior

100x70x10 Large WC/Co cemented carbide hard alloy(monolithic)

2 pieces and 20 min./cycle, 10 times continuous operation

Comparison of the SPS sintered Fine WC/Co hard alloy

and other commercial products by conventional method

1400

1600

1800

2000

2200

2400

2600

2800

100 150 200 250 300 350 400 450

Transverse Rupture Strength (Kgf/mm2)

M78

TC10

TC20 A

B C

D E

Har

dnes

s m

Hv

(kgf

/m

m2 )

HR

A

95

94

89

91

90

92

93

Nano-WC :Examples of Aspheric Glass Lens Molds

Binderless Pure-WC Oxidation Resistance

Comparing weight loss changes of surface area per specimens after 70010hrs heating in atmospheric furnace

0.050

0.055

0.060

0.065

0.070

0.075

0.080

0.085

0.090

M78 A company B company

Super Hard Alloy Materials

Am

ou

nt

of

Oxid

ati

on

(g/c

m2)

SPSed pure-WC

Full-Tunnel type SPS Production System SPS JOB-SHOP company using Production-type SPS Systems in Hokkaido

Pure-WC SPS sintered compact and products

( JAPAN : OHTA SEIKI Co.,Ltd )

Largest in the World

Semi-Tunnel type SPS Production System

The 5th Generation-type

JAPAN/ SINER LAND INC. Box type Chamber/Auto Feeding System

Max.pressure: tonfMN)

Max. pulse current

,A

-Chamber system Pre-heating stage SPS sintering stage

Cooling stage Invertor Pulse Generator

(300mm:Max.85MPa)

Semi-Tunnel type SPS Production System World s Largest SPS System 00 tonf(MN ) / 40,000A

Pre-HEATING SPS SINTERING COOLING

IN-LET OUT-LET

JAPAN/SINER LAND INC.

Large size Production -type SPS System

Max. Pressure3 ~ 10 MN (300~1,000 tonf

Max. Pulse Current Out-put20,00040,000 A

JPX-300G-MN

300 Al2O3 (RD:98%)

The 5th Generation

Features

Flexible system

Additional Multi-chamber system is available

for an automated production with a special conveyer.

The latest hardware Specially designed ON-OFF DC Pulse Generator

for High efficiency and Energy-saving

Newly developed JPX Touch Panel operation screens

High cooling performance

Safety and reliable long-run operation

Easy maintenance

LABOX Touch Panel System and Vacuum Chamber ModelLABOX-1575150KN/500010000A)

The 5th Generation One Box ALL-IN ONEAC Servo Motor System

Medium size LABOX SPS SystemLABOXTM M-series

Custom-type Small size LABOX SPS System (C-series) With Glove Box &Turbo molecular Vacuum Pump

MODELLABOX-125GH JAPAN/SINER LAND INC.

The 5th Generation

Typical 20 small size examples of bulk FGMs

from left : ZrO/SUS ZrO/Ni Cu/SUS Al/Polyimide AlO/Ti FGMs

Functionally Graded Materials (FGMs)

20mm Cu/Thermosetting-Polyimide FGM 20mm Al/Thermosetting-Polyimide FGM

Examples of Polymer- Metal system FGMs

Scaling-up & Homogenization Functionally Graded Materials of ZrO2 (3Y)/Stainless Steel FGM

55 mm

20 mm 55

mm

40 mm

20mm 30mm 50mm 80mm

Temperature

gradient die

(NEDO Project)

Example of Perpendicular type 3-D formed 80mm Large-size ZrO2 (3Y)/ Ti / Ti-Al system FGM

50%

5

7

20

8

Co WC

Large FGM block was machined by Wire-cut EDM and Grinding machines

Applied for Press stamping Dies, and the life time is 7~8 times longer than conventional products

WC0.5 m-6%Co

WC0.5 m-4%Co

WC3.5 m-15%Co

WC5.0 m-20%Co

m

[Scaling-up II]

Square-Shaped Large-Size of 100mmx100mmx40~60mm WC/Co Cemented Carbide Hard-Alloy FGM

Profile of micro hardness on Co content graded cemented carbide by SPS

100x100x40mm large-size WC/Co FGM fabricated by SPS

SEM micrograph (left) and EPMA analyses (center & right) of 4-layered WC/Co FGM

Examples of WC/Co, WC/Co/Ni System FGMs for Press Stamping Dies & Punches

Wire-Cut Electrical

Discharge Machining on

FGM

Optical microphotograph and Vickers hardness

distribution behavior of Weldable WC/Ni system

FGM tile

TIG Welding using WC/Ni FGM and FGM

Screw products (lower left) and FGM built-

in Extruding machine (lower right)

Application Example for Screw of Extruding Machine Weldable WC/Ni FGM (Ni10%,20%,30wt% 3 layers

Lifetime of Conventional Screw8001000 Hours WC/Ni FGM Screwmore than 3000 Hours

Desulfurization Pellets Operation of Pellet Extrusion

Vickers Hardness Comparison

PLS/ HP/ HIP and SPS on AlO

Easy to Fabricate Various High-Quality Advanced Fine Ceramics

SPS sintering temperature 14001600

Applied Pressure 3050MPa

Heating-Up & Holding Time 1520 min R.D 99100

Hardness 20GPa<

Examples of SiN+ AlO Composite Material

with Near Net-Shape Forming

SPS Vs. HP Sinterability Comparison

on SiC (with addictive)

Advanced Ceramic Materials

NANO-SiC Compacts Sintered by SPS at 1700

Rel

ati

ve

Den

sity

[%]

Sintering Temperature[]

TEM Microphotographs

(The average diameter of the starting MA powder materials aprox. 30nm)

Nano SiC Porus

RD: 62.5%

Holding time : 0min

Nano SiC densematerials

RD: 97.7%

Holding time : 10min The relationship between MA time and

Si, C Powder XRD (X-Ray Diffraction)

Str

ength

[a.u

.]

Str

ength

[a.u

.]

GeneralCommercialProducts

SPS Sintered Nozzle

Advantage of SPS sintered

Nozzle

Vickers Hardness

(Hv)900-1100 2100-2200 High-Hardness

RelativeDensity (%) 91 100 High-Density

Surface Rough Mirrored surface

Mirror finished surface by

Near Net Shape

Lifetime 1 day 10 days 10 times longer Lifetime

Comparison between SPS sintered nozzle and general commercial products

3-Dimensional complex shape (Outer-Tapered type) of Al2O3 Blasting Nozzle by SPS

Material: Al2O3 Dimensions: Length: 60mm Outer diameter (Tapered):

30/15mm Inner diameter (Straight): 6mm

Material: Al2O3

Material: pure-WC(no addtives) Material: SiC (with addtives)

Dimensions: 200x10mm

Dimensions: 100x16~50mm Dimensions: 150x20mm

R.D: 99-100%

R.D99-100% R.D 99-100%

Material: Al2O3

Dimensions: 300x6mm

Examples of Large-size Ceramics Fabricated by SPS

0

200

400

600

800

1000

1200

0 10 20 30 40 50 60 70 80

()

54min. Keep Start

74Min. Energizing End

SPS Temperature Distribution Behavior TEST-II ( 200mm: Example of abnormal SPS machine conditions)

T.C Rear side

T.C Front

T.C Right

T.C Left

Chamber Front

T.R.M. Front-Right

300 tonf Temp. Distribution TEST-II Settings R F L Bk F-R(T.R.M)

3-D Titanium Alloy(Ti-6Al-4V) Dimensions:80mm x 48mm Thickness:3~5mm

Relative density:99-100% Hardness:HRC35Average

Elongation: 10%after heat treatment 20%

SPS wrought Ti alloy

HardnessHRC 35 2832 Elongation 20 1518

Tensile strengthMPa 1038 895980 0.2% Yield strengthMPa 928 825928

Titanium and composite Materials

Moving from R&D Proto-type Product to Practical

Industrial use High Volume Product [I]

Bio-Medical Applications / Porous Titanium Alloy for Artificial Bones & Implants

Ti/Ti-6Al-4V

ZrO2

Dental Implant

Hip-Bone Joint Assy.

Pelvis

Acetabular Cup

Stem

Ball head

Rapidly

solidified

powder

Super

plastic

forming

Powder

Consolidation

Component

Fine micro-structure < 1 um

Low temperature sintering

High strain rate > 10-2s-1

From R&D Product to Practical Industrial use High Volume Product [II]

Fabricating process for high performance aluminum alloy components

Nano crystalline

particle used

Nano-structural

sintered preform

compact

Appearance of Super-

Plasticity

Applications :

Automobile components

Electronics components

& others

Application for Super Thermal Conductive Materials by SPS

ApplicationsSemiconductorFuel cellLED cooling, Heat sink etc. ( contributed by Moriya Cuterly Labolatory Co,.Ltd - Japan )

Advanced MMC/ Metal-C Composite STC-CH(Cu):630W/mK STC-AH(Al):540W/mK!!

Moving from R&D Proto-type Product to Practical Industrial use High Volume Product [II]

Other

materials:Al,Cu /CNF,CNT

FeSi2

[A] [B]

for Future Industries : Power Generation and Clean Energy

JAXA

SPS

[A] [B]

Thermoelectric Materials

PM2012 International Congress & Exhibition (Yokohama)

JASCJapan SPS Consosium Supporting system

SPS Job-shop

R&D support

Proto production

Pilot production

Mas Production

SPS machine mfg. Production system design and supply

Advantage & Disadvantage

Rapid sintering

& high heating-up

High quality sintered compact

(finer microstructure)

Mass-production

& Cost ?

Easy to receive SPS machine damages

Difficult to determine optimum SPS sintering Conditions on Large size and/or complex shape

Die and punch Life time Cycle time, maintenance and Raw powder cost (possibly 24 hours operation)

The SPS still have a variety of practical industrial applications issues to be solved before the full potential of the SPS manufacturing processes are realized.

The example results suggested that the SPSed large size ceramics usually contained higher residual stresses than small size inside of the sintered body, and especially their SPS temperature distribution behavior difference in the powder material during heating-up, even applying the same SPS sintering conditions. Determination of the optimized SPS process conditions on the different ceramics materials is now in progress for practical industrialization.

These issues include enlarging process, homogenization technique, reduction of residual stresses, shape & size effects and system automation, increasing the pulse current density control and capacity, and versatility of functions in the hardware, and the creation of a SPS sintering technology data base and improvements to reliability and reproducibility in terms of software.

It is also important to develop suitable powder materials and establish 3-D forming fabrication techniques according to the required SPS applications so that they match the characteristics of the SPS Production process and systems.

OUTLOOK & SUMMARY

SPS brings the world together Rainbow in Maui, Hawaii

Pac-Rim 6 / 2005 Sep. Thank you !!