Creep Seminar Ruchti

8/18/2019 Creep Seminar Ruchti

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Intelligent testing

Creep Testing

with Messphysik

Peter Ruchti

Hereford, September 2012


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Agenda

Creep testing with Messphysik

Actual potential

Furnace and tem erature controller

Working principles metals

Working principles plastics / composites

Creep Testing with Messphysik - Base September 2012

DI Peter Ruchti (MSc.)

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Customer projects on other materials

Customer projects on metals

Customer projects on plastics


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Actual potential

Today there is a high need of energy saving and reduction of emissions.With higher temperature (T) and pressure (p) the efficiency of HT-systems will be

better and therefore energy and emissions can be saved or reduced.

HT-Power plant Aerospace Petrochemical Industry



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960 …. 1200 °C > 1200°C

50 bar …. > 110 bar

500 …. 650 °C > 700°C

170 bar …. > 350 bar

Steam turbine Gas turbine


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Actual potential

Plastic used as a basic material in several industries combines some importantadvantages: constant quality, reliability and in distinctive energy efficiency.

Engineering plastics and fiber-reinforced plastics enable new developments in:

Automotive Aerospace Wind energy



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Battery, body panels,bumpers, dashboard,

door panels, fuel system,interior and exterior trims,lighting systems, seats,

seatbelts, airbags, under

shieldsupholstery

Rotor blade

Housing

Extensive use of plasticcomposites in the

Boeing 787 Dreamliner

reduces weight, fuel consumptionand allows new design concepts.


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The consequence: A need of new High Temperature (HT) -Materials and relevant material data.

Higher pressurehigher mechanical

load

Need of material strength data

creep, stress rupture strength, creep rupture strength

Stress and creep rupture tests

Actual potential



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Higher temperatureshigher thermical

load

Cost reductionless conservative

part dimensioning

optimized service

intervals

Tensile strength, strain limits, E-ModulusQuasi-static tests

Life time prediction with cyclic loads

Fatigue tests


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Actual potential

Messphysik order entry: Academia, Energy and Metal are themost dominant industries.

26%

4% 3%

Creep order entry by industry2008-2012

Academia



6

1%

20%

46%

Academia

Automotive

Energy

Metal

Paper

Plastics

Textile


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Actual potential

8%

1%7%

2%

Home market

Rest of Europe

Creep order entry by regions2008-2012

Messphysik order entry: The European market makes up overhalf of the creep order entry. A quarter of the creep order entry

arises from the Asian market.



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46%

26%

11%

8% Rest of Europe

Asia without ChinaChina

USA

Russian Federation

Latin Amerika


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Agenda


Actual potential






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Direct Load Lever rm Spindle

Dead

Weight

Dead

Weight

Spring

Loaded

Single

Spindle

Dual

Spindle

Schematic

Working principles - metals



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Run duration > 10.000 h > 10.000 h > 10.000 h < 10.000 h < 10.000 h

Control

modeForce Force

Force, Stress,

Strain

Force, Stress,

Strain

Force, Stress,

Strain

Load strings

in one frame ~ 100 ~ 12 ~ 12 Multi 1


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Lever arm creep testers – schematic diagram 1l0 l1

F = W∗(l /l ) F

Working principles



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W

F = W∗(l0/l1) F


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± 0.05°

eendnd switchswitch

lloadoad cellcell

Lever arm creep testers – schematic diagram 2

Working principles



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F

s

Dead weight: f forceorce = const.= const. Spring load: f forceorce,, stress, strainstress, strain = const.= const.

W


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Working principles

0,05

limit switchlimit switch

loading and load control by gravity

automatic adjustment of lever arm atcreep of specimen

control parameter: balance of lever arm

application: creep test with constant load

Principle Creep Test: lever arm with dead weight



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W

t

F

F=F= constantconstant

12

100%

2%

According toweight distribution

application: creep test with constant load


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Working principles

Principle Creep Test: lever arm with preloaded spring

loading by preloaded spring

load controlling by controlling the

load cell signal

application: creep test

with constant load or loading blocks

load cell =load cell =

controlcontrol

channelchannel

extensometer =extensometer =

measurement measurement



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t

F

t

F

F/F/ == constantconstant F/F/ == bblocklock

13

100%

0,5%

stepless

with constant load or loading blocks


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Principle Creep Test: lever arm with preloaded spring

loading by preloaded spring

strain control by controlling the

Extensometer signal

application: relaxation test

Working principles

load cell =load cell =measurement measurement

extensometer =extensometer =controlcontrol

channelchannel



application: relaxation test

or other strain controlled tests

t

14


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Spindle-driven creep testers – schematic diagram

LoadLoad

cellcell

Working principles

LoadLoad

cellcell

Closed loop

control



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Single-spindle drive Dual-spindle drive

control

Closed loop

control


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Agenda


Actual potential






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Direct Load Lever rm Spindle

Dead

Weight

Dead

Weight

Single

Spindle

Multi-

station

Schematic

Working principles – plastics and composites



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Run duration > 10.000 h > 10.000 h < 10.000 h < 10.000 h

Control

modeForce Force

Force, Stress,

Strain

Force, Stress,

Strain

Load strings

in one frame ~ 100 ~ 12 1 ~6


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LoadLoad

cellcell

LoadLoad

cellcell

LoadLoad

cellcell

LoadLoad

cellcell

LoadLoad

cellcell

LoadLoad

cellcell


1x environmental chamber

6x

6x

Multi-station creep testers – schematic diagram



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6x closedloop control

Multi-station creep testers


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The most dominant machine type with creep tests on plastics is themulti-station creep tester.


1 to 6 test axes per load frame

Central spindle with each test axis andindividual closed-loop-control

One temperature chamber for 1 to 6 test

axes



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axes

Alternatively two temperature chambers in

one load frame (each for maximum 3 test

axes)

Non-contacting strain measurment

(recommended by testing standards)


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Strain measurement with Multiplexing – shematic diagramm

…

n-Specimenin field of view

of 1 camera*

Multiplexing of cameras

Camera fornon-contacting Extensometer

up to 12… …




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Multiplexing Controllerson 1 Master-PC

Multi-station

Master-PC

Load Lift

…

… * dependant on gage length, elongation anddistance between stations, Standard: 3-4 specimen

up to 256 Multiplex-PCs


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Strain measurement with Multiplexing – advantages

Accuracy of each station measurement + 0,01mm

Fixed cameras therefore no uncertainty due to

moving cameras

Continuous measurement from backside of the

testing system




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Loading of new specimens does not interrupt

measurement of other stations

Free definition of time schedule for strain

measurement


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Multistation Master PC with testXpert Multistation Software

Test monitoring with tree structure

e.g. automatic measuring of channels,

time, strain and temperature Detection of break/rupture

Data storage incl. continuation of

interrupted test




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Test analysis

Results acc. to ISO 899-1 and ISO

899-2, ASTM D 2990, e.g. strain rate,

creep strength, creep modulus

Statistics

Automated reporting


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Agenda


Actual potential






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High temperature furnaceAn important component of the creep system

3-Zone furnace up to 1.200°C / 1.400°C

Precise temperature distribution by 3-zone-temperature-controller Internal Diameter: 100 mm, Heated length: 300 mm

Vertical positioning of furnace:

Furnace and Temperature Controller



openings for load string, Thermocouples and Extensometers

(optional: side windows for optical strain measurement)

3 Thermocouples for furnace controller;

up to 3 couples for Temperature

control at the specimen

Light, thermal insulation material (free of asbestos)

Casing made of stainless steel

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The intelligent control-algorithm minimizes efforts whensetting the control parameters and ensures standard compliant

specimen temperatures without overshoots.

Automated settings withthe 3-channeltemperature controller

for specimentemperatures between

° °


Creep Testing with Messphysik - Base September 2012DI Peter Ruchti (MSc.)

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.

Timesaving andoptimized use ofspecimen because thecomplex empirical

determination of control-parameters is no longer

required

Temperature tolerancesaccording to ISO 204

und ASTM E 139

Screenshots

vorläufig


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The Zwick temperature controller is timesaving andflexible in use.

3-channel Controller (Eurotherm 2604)

Integrated, technical sophisticated control-algorithm for a

constant temperature deviation along specimen and toavoid temperature overshoots

Empirical determined control parameters for different

temperatures are no longer required



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Not sensitive to different air flow conditions (openings, etc.)

Interface for 6 thermocouples

− 3 pcs. to control the specimen temperature

− 3 pcs. to measure the furnace temperature

Digital display of temperature

One RS 232 Interface to PC with 6 virtual channels

Stand Alone- or testXpert-operation possible

Can be used for different 3-zone-furnaces

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PIDPIDTemp_1Temp_1

The multi-channel control-algorithm controls thespecimen temperature precisely.



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PIDPIDMaster Master PIDPIDTemp_2Temp_2

PIDPIDTemp_3Temp_3


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Even with lower test temperatures the specimen temperaturesstay within the temperature tolerances of +/-2K.

T e m p e r a t u

r e i n

C

Furnace temperature

Example: test at 80 C, function of specimen and furnace temperatures



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Test time in h

T e m p e r a t u

r e i n Furnace temperature

Specimen temperture

1,6


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Also with high furnace temperatures, temperature tolerances areattained quickly without overshoots.Example: test at 1.000°C, function of specimen and furnace temperatures

° C

1000



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T e m p e r a t u r e i

Test time in h

850

900

950

1,0 1,2 1,4 1,6 1,8


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The flexible control of the furnace temperature enables precisetemperature blocks on the specimen.

T e m p e r a t u r e i n

C

Example: test with temperature blocks of 5 C



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T e m p e r a t u r e i n

Test time in h

95

100

105

110

1 2 3 4 5


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Optimized heating parameters make short heat-up times possible.Therefore higher specimen through-puts can be achieved.

° C

Example: When mounting a specimen in a preheated furnace

further warm up times are reduced.

Opening of pre-heated furnace =

interruption ofcontrolling



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T e m p e r a t u r e i

Test time in min

Closing of partly cooleddown furnace

= restart of controlling

Time interval of specimen replacement

Due to the reduction, theheat-up time comes up to37 minutes


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Agenda


Actual potential





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Institute of aviation materials, Russia

Type of Test: High Temperature Tensile Creep Test

Testing Machine: Kappa 50 SS

Kappa 50 DS

Applied Standard: ASTM E 139


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Specimen Types: Flat, threaded head (M10/Ø8 / M14/Ø10)

Environment: Elevated temperature up to +1.200°C

Strain: Creep test with strain measurement on specimen

Customer specific feature: Axial- & Transversal strain measurement


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Type of Test: High Temperature Creep Crack Growth Test


Applied Standard: ASTM E 1457

Specimen Types: CT-Specimen

Atomic Research Institute, India



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nv ronmen : m en an e eva e empera ure up o .

Strain: Measurement of load line deflection with

rod-in-tube extensometer, measurement

of creep crack growth with DCPD method


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Measurement of creep crackgrowth with DCPD-Connection

Measurement of

load line deflection


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Power supply

Output signal

(potential drop)


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D i s p l a c e m e n t i n m m

S t a n d

a r d f o r c e i n N

Load line displacement Standard force

In a single test both load line displacement and crack size ismeasured. Example: CCG test with CT-specimen at 5.985N and 700 C


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D i s p l a c e m e n t i n m m

S t a n d

a r d f o r c e i n N

Creep time in h


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In a single test both load line displacement and crack size ismeasured. Example: CCG test with CT-specimen at 5.985N and 700 C


Crack size Force

S t a n d a

r d f o r c e i n N

C r a c k

s i z e i n m m


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S t a n d a

r d f o r c e i n N

C r a c k

s i z e i n m m

Creep time in h

C


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Nuclear Research Center, France

Type of Test: High Temperature Tensile Creep Test

Testing Machine: Kappa 50 DS

Applied Standard: Customer specific

Specimen Types: Material: zirconium

Flat, round and tubular specimen,



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(coupling by Swagelock clamping)

Environment: Ambient and elevated temperature up to +600°C

Strain: Optical measurement of axial strain and

reduction in width

Customer specific feature: Tunnel between Extensometer and HT-furnace 2

optical windows in HT-furnace

Test Results: Creep Curve

C t j t t l


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C t j t t l


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The axial and the transverse strain is measured contactlessunder high temperature.Example: Start of creep test at 450°C


0.06

0.08

0.06

0.08

m m m

dL/t db/t

0,06

0,08

0,06

0,08


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0 2 4 6 8 10

0.00

0.02

0.04

0.00

0.02

0.04

Test time in h

S t r

a i n i n m

C h a n g e i n w i d t h i

C h a n g e

i n

w i d t h i n

m

S t r a i n

i n

Test time in hours4 106

0,00

0

0,02

2 8

0,00

0,02

C t j t t l


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Type of Test: Strain creep test

Testing Machine: Kappa 50 LA spring

Applied Standard: ASTM F519

Specimen Types: Round, threaded head

Landing Gear Company, Netherlands


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Test time: up to 200h Customer specific feature: 4 specimen in series in the testing axis

C t j t t l


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Landing Gear Company, Netherlands


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Landing Gear Company, NetherlandsTest process to determine hydrogen embrittlement acc. to ASTM F519

1. Tensile testing to determine breaking strength

2. Creep testing with 75% of breaking strengtha. All 4 specimen resist the test of 200h –> no hydrogen embrittlement of

specimen and specimen surface treating


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. -

200h of total test time is reached. Then increase of force in 5%-steps (2htest time for each step) until the force has reached 90%.

2h

2h80 %

2h 85%

3 specimen4 specimen

time

force

75 %

t = x t = 200-x

t = 200

90%

t = 206



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Atomic Research Centre, India Type of Test: Creep, relaxation,

user-programmable loading cycles

“fracture toughness”

Testing Machine: Kappa 100 DS

Applied Standard: ASTM E 139, ISO 204

ASTM E 399, ISO 12135


Creep Testing with Messphysik - Base September 2012DI Peter Ruchti (MSc.)49

Specimen Types: metal and ceramics specimens

Environment: metal up to +1.200°C

ceramics up to +1.600°C

Loading: constant stress creep tests

Customer specific feature: 1 furnace up to +1.200°C and

1 furnace up to +1.600°C

This furnaces are alternately pivoted



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Creep test machine for multiple materials, environments andapplications.





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Tensile TestBending Test

Atomic Research Centre, IndiaTests at ambient temperature




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Creep Tensile Test Creep Crack Growth

Atomic Research Centre, IndiaTests at high temperature




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The true strain rate can be automatically controlled.With compression tests the crosshead speed is decreasing.Example: Compression test with true strain rate of 0,1% / sec


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D e f o r m a t i o

n i n %



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Very low traverse speeds are possible.Example: 1 µm / hour

60

80

100

m n µ m

dL/t


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0 2000 4000 6000

0

20

40

Test time in min

S

t r a i n i n µ

S t r a i n i

Test time in min



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Compliance to a corridor of +/- 0,1% at a traverse-speed of 1µm/h.

s t r a i n i n µ m

Nominal strain /t


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Test time in h

N o m

i n a l

Agenda


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Actual potential





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p j p

Specialty chemicals group, Germany

Type of Test: Creep and relaxation tests and

user-programmed stress cycles

Testing Machine: 2x Kappa 50 SS – 5 x 10 kN Applied Standard: ISO 527-2 Type 1A

Specimen Types: Tensile specimens of plastic

Creep Testing with Messphysik Feber 2012


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Tensile specimens according to ISO 527-2 Type 1A

Tensile specimens with shoulder width 35 mm

Environment: Ambient temperature up to + 200°C

Loading: Motor via ball screw drive

Strain: Optical strain measurement

Customer specific feature: 5 load trains together in 1 temperature chamber

Distance of the test axes to each other: 105 mm



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5858



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5959



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Creep curve easily displayed with testXpert – determination of

minimum creep speed and three creep phases

Example: Tensile Creep Test at 60 C and 16 MPa



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6161

Front view Rear view

Agenda


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Actual potential






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Technical University, Austria: ceramics

Type of Test: Creep compression tests


Specimen Types: Ø35mm, h=70mm

Environment: Elevated temperature up to + 1.600°C

Creep Testing with Messphysik – diverse Materials September 2012


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.

Strain: strain measurement from two opposing

positions, max. compression 5-8%

Customer specific feature: Tests on refractory materials



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Technical University, Austria: ceramics



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The two-sided measurement of the compression is displayed

in testXpert both separately and averaged.Example: Test at 1.500 °C and konstant force of 7.500 N



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Technical University, Austria: creep tensile tests on refractory

material

water cooling input

water cooling output

watercooling

loadstring

alignment unit



adhesive area

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adhesive area


water cooling input


refractory material

heated zone

adhesive area

Creep Seminar Ruchti

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