Tampere Wear Center concentrates on both scientific and practical aspects of wear and tribology. Strengthens research in the field of wear and tribology of materials Special expertise areas heavy abrasion, impact wear, fretting and tribology of machine elements, such as gears, bearings, brakes, seals, and frictional joints

1. Towards comprehensive
control of wear
Kati Valtonen
Tampere University of Technology
Faculty of Engineering Sciences
Department of Materials Science
Tampere Wear Center
Fysikaalisen metallurgian hyödyntäminen terästä
käyttävässä teollisuudessa –seminaari
2. – 3.11.2016, POHTO, Oulu

2. 2.11.2016 2
Tampere University of Technology
Collaborates
with approx. 230
universities
around the world
Quality assurance
system audited by
The Finnish Higher
Education
Evaluation Council
in 2014
Started operating
in the form of
a foundation
in 2010
Approx. 1,700
employees and
8,300 students
(2015)
Established
in 1965

3. Department of Materials Science
• The only higher education unit
in Finland covering all material
groups
• Over 1000 M.Sc. (Eng.), 80
Lic.Tech., and 70 Ph.D. thesis
and more than 6000
publications since 1969
• High-level basic research of
the structure, properties,
processing, and use of
materials
• Researcher with knowledge of
and expertise in all groups of
materials
• Versatile and up-to-date
research and testing equipment
• Strong collaboration with
industry and academic units
Internationally high-level know-how
on ALL materials based on strong
interdisciplinary basic research

4. Tampere Wear Center
• Concentrates on both
scientific and practical
aspects of wear and
tribology
• Strengthens research in
the field of wear and
tribology of materials
• Special expertise areas
heavy abrasion, impact
wear, fretting and
tribology of machine
elements, such as gears,
bearings, brakes, seals,
and frictional joints

5. Tampere Wear Center - Research equipment
• Wear testing: Pin-on-disk/Ball-on-disk, Crushing pin-on-disk,
Uniaxial crusher, Dual pivoted jaw crusher, Impeller-tumbler,
Erosion tester, High-speed slurry-pot type erosion tester, Slurry
erosion-corrosion tester, Cavitation erosion tester, High velocity
particle impactor, Ball-on-block, Hammer mill, Single disc refiner,
Block-on-ring, Rubber wheel abrasion testers, etc.
• Tribology and machine elements test rigs: Test rigs for journal,
thrust, and rolling bearings, FZG, Twin-disc test rig, Fretting wear
and fatigue test rigs, Vibration Testing, etc.
• Microscopes (FEG-SEM, FIB-SEM, TEM, 3D profilometer, etc.)
• Hopkinson Split Bar systems
• Digital image correlation systems
• Mechanical testing
• Thermal spraying
• Other equipment at DMS

6. Scales of tribological testing
Helena Ronkainen: Friction and wear properties – tribotesting as a tool for performance evaluation, TWC International Seminar 2012
Decreasedcost,increasedcontrol
Increasedrealism

7. Crushing Pin-on-disk
• Pin is repeatedly pressed against
the gravel bed and the disk with a
pneumatic cylinder (200-500N)
• Pin does not come into direct
contact with the disk at any time 
wear of the components due to
abrasive ploughing and cutting on
the pin and disk surfaces
• During the test, the abrasive size
decreases at different rates,
depending on the pin-disk
combination.
• Simulates cone or jaw crusher

8. 0.142
0.158
0.163
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0.172
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0.186
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0.216
0
100
200
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500
600
700
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900
1000
0.000
0.050
0.100
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0 2 15 4 14 3 10 11 5 24 18 17 6 16 1
Surfacehardness[HV5]
Massloss[g]
Up to 50 % difference in abrasion wear
performance in similar 400HB steels
• 15 commercially available 400 HB steels were tested with crushing
pin-on-disk. Five steels were selected to closer study.
• The best wear performance was achieved by steels having good
orientation of the deformed surface layer
• The highest initial hardness and also highest local work hardening
did not result as best performance
Ojala, N. et al., Effects of composition and
microstructure on abrasive wear
performance of quenched wear resistant
steels, Wear 317(1–2): 225–232(2014).
B
E
EBA C D

9. Dual pivoted jaw crusher
• Laboratory scale jaw crusher for
studying the mechanisms of
abrasive wear during mineral
crushing
• Key design features:
– control of jaw movement without
changing the test geometry,
enabling accurate control of the
compression-sliding ratio
– versatile instrumentation for
monitoring the wear processes,
including piezoelectric force
sensors, high speed video
systems, etc.
• Test outcomes
– wear of both jaw specimen
– work in Fz and Fy directions
– feed size reduction to product
• Specimen
– jaw plate size 75*25*10 mm
– abrasive particle size 6-14 mm
Jaw1 Jaw2
Jaw1
Jaw2
Samples

10. Movement of jaws with 5°+5° jaw angles
0° frame setup
ΔY= 0.3 mm
ΔZ= 3.0 mm
45° frame setup
ΔY=3.23 mm
ΔZ=3.27 mm
90° frame setup
ΔY= 24.0 mm
ΔZ= 4.98 mm
Z
Y
Terva, J., et al. “Correlation of wear and work in dual pivoted jaw crusher tests”, Proceedings of Nordtrib 2016
(high speed video = 20 times slower)

11. High velocity particle impactor (HVPI)
• Developed for the model verification and to identify the basic mechanisms influencing the impact wear and failure behavior of materials
• Key design features:
– various angles and impact energies; projectile speed: 30…200 m/s
– suitable for various materials: metals, coatings, elastomers, hybrids, ...
– projectiles: metallic or ceramic ball bearing balls, cylinders, bullets, and rocks
– video recording: high speed camera NAC MEMRECAM up to 80 000 fps or LaVision StrainMaster 3D DIC systems (high and low rate)
– cooling setup: temperatures down to -80°C can be reached; cooling with nitrogen gas, impact happens in ambient air
Trap wall
Target
assembly
Speed
measurement
device Smooth bore
Pressure
control
Pressurized
air tank
Specimen
Cooling setup

12. Impacts recorded with high speed video
camera
Temperature -40°C
Sample angle 30°
Velocity ~78 m/s
Temperature -40°C
Sample angle 60°
Velocity ~112 m/s
Ratia, V., et al. “Impact behavior of
martensitic steel at low temperatures”,
Proceedings of Nordtrib 2016

13. Comparison of laboratory wear test results with
the in-service performance of cutting edges of
loader buckets
• The cutting edge of the underground mining loader bucket had been run 928
hours in an underground mine with quarry gravel.
– The dimensions of the cutting edge had been determined before and after the test:
27.1 percent of its weight, i.e. 335 kg was lost [Keltamäki & Ylitolva 2014].
– The wear rate had been highest on the underside of the bucket
– Material was 500 HB grade wear resistant steel
• In-service cutting edge was investigated and its
wear behavior was compared with laboratory
tested 400 HB and 500 HB grade steel samples
– Crushing pin-on-disc, uniaxial crusher, their
combination, impeller-tumbler, and high-speed
slurry-pot with dry abrasive bed (dry-pot)
Underside
Original
profile
Valtonen, K, et al. Proceedings of Nordtrib 2016

14. Crushing pin-on-disc (CPoD) Uniaxial crusher (UC)
Impeller-tumbler Slurry-pot with dry granite bed (dry-pot)
90 min test
(= 3 x 30 min)
1000 mm2 area
Cyclic loading
240 N force
2-10 mm granite
500 cycles
1000 mm2 area
53 kN force
4-6.3 mm granite
Combined test:
500 cycles UC +
30 min CPoD
360 min test
(= 24 x 15 min)
1200 mm2 area
700 rpm
8-10 mm granite
60 min test
(= 2 x 30 min)
2540 mm2 area
500 rpm
8-10 mm granite

15. Wear rates were highest in the dry-pot and
crushing pin-on-disc tests
• The wear rate decreased during
the crushing pin-on-disc tests
• Compared to the other methods,
the contact mechanism in the
impeller-tumbler is more impacting
than abrasive, which at least partly
explains the different results
• In the combined UC + CPoD tests,
the mass loss in the crushing pin-
on-disc test was 70% higher during
the first 10 minutes compared to
end of the test 0
50
100
150
200
250
300
350
400
450
500
0 10 20 30 40 50 60
Massloss/nominalweararea[g/m2] Contact time [min]
Impeller-tumbler
Crushing pin-on-disc
Uniaxial crusher
Uniaxial crusher & crushing pin-on-disc
Dry-pot
500HB steel

16. Uniaxial crusher (UC)
Combined UC + CPoD
Dry-pot
White layers were formed in field,
uniaxial crusher, and dry-pot samples
• Microhardness of the white layers was up to 700
HV0.05 in underside of the field sample
• Thickness from few micrometers up to 130 µm and in
underside of the field sample even over 4 mm wide
– much thinner and smaller in laboratory tests
• In CPoD tests, delamination of white layers formed in
uniaxial crushing
• Adiabatic shear bands formed in impeller-tumbler tests
 more impacting than abrasive
Underside of the cutting-edge sample

17. Cutting edge: underside upperside tip
Crushing pin-on-disc Uniaxial crusher Combined UC + CPoD

18. Impeller-tumbler
Crushing pin-on-disc
Dry-potCutting edge
Combined UC + CPoDUniaxial crusher

19. 0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.1
Crushing pod Uniaxial crusher Combined CPoD + UC Impeller-tumbler Dry-pot Cutting edge
Wearrate[mm/h] 400 HB 500 HB
Valtonen, K, et al. “Comparison of laboratory wear test results with the in-service
performance of cutting edges of loader buckets”, Proceedings of Nordtrib 2016

20. Conclusions
• The work hardening behavior of the studied steel could be simulated with all testing
methods used in this work.
– The hardened layers and the formed white layers appear to be thinner than in the in-service
conditions due to the lower applied forces.
• The dry-pot wear testing method with an abrasive gravel bed produced similar wear
rates and wear surfaces as the in-service operation.
– The abrasive type and size and the contact mechanisms were also quite similar when
compared to the in-service conditions.
• In the crushing pin-on-disc tests the wear type was also similar but the forces much
lower than in the in-service conditions.
• In the uniaxial crushing tests, the rock embedded in the sample in the similar manner
as in the tip of the cutting edge due to the high compression forces.
• In the impeller-tumbler tests, the impact effect is dominant.
• Proper simulation of the in-service conditions demands constant development
of the test methods and careful evaluation of the obtained results.

22. Metals Technology
• Metals and fabrication methods, heat treatments and joining
methods
• Materials science of metals; metallurgy and engineering properties
• New metallic materials; high entropy alloys
• Novel thin sheet steels; Quench & Partitioning (Q&P) alloys, Press
Hardening Boron Steels (PHS), Complex Phase (CP) Steels
• Forming of thin sheet; Deep drawing, Hole expansion of steel
• Heat treatments; case hardening, bake hardening, Q&P treatment
• Others: The long-term durability of metal-metal adhesive joints
Contact: Pasi Peura
AlCoCrCuFeNi -HEA

23. Press Hardening Boron Steels
• Development of process parameters, steel and protective coatings
• Laboratory press hardening equipment
• Basic steel 22MnB5
• Optimised galvannealed coating (ZF) for PHS
• The effect of the initial microstructure on the austenite grain size at
the end of austenisation is significant => It also effect the final
strength values
• Example Full hard vesus Batch annealed
– FH Vickers hardness HV482
– BA HV517
Järvinen et al. 2014 - 2016
22MnB5

24. Surface Engineering – research expertise
• Processing of advanced coatings by thermal spray, laser and
thin film processes
• Materials science of coatings and thin films - microstructure
and engineering properties
• Application-related properties and performance of
advanced surfaces and coatings
• Industrial applications of coatings and surface treatments

25. Thermal Spray Center Finland
• Strategic collaboration platform between Tampere University of Technology,
Department of Materials Science, and VTT Technical Research Centre of
Finland Ltd.
• Aim is to be at the leading edge of this research field thus creating a perfect
platform for international high-impact research and remarkable national
industrial influence.
• Modern and well-equipped thermal spray research laboratory with supporting
materials research laboratories of TUT and VTT.

26. Thermal spraying at
Plasma spray equipment
• Sulzer Metco F4
• Saint Gobain ProPlasma
HVOF and HVAF spray equipment
• Sulzer Metco DJ-Standard (propane), DJ-1000 (propane),
DJ-2600 (hydrogen), DJ-2700 (propane, ethene) and Hybrid
DJ-2600 (hydrogen)
• GTV Top Gun (hydrogen, ethene)
• S-HVOF (suspension)
• Miller HV-2000 (hydrogen, ethene)
• Thermico HP-HVOF liquid fuel torch
• Kermetico propane/air system (HVAF)
• UniqueCoat M3TM (HVAF)
Flame spray equipment
• Sulzer Metco 6P-II and Castolin DS 8000 (powder)
• Sulzer Metco 12E (wire)
• Saint Gobain MasterJet (wire, rod, flexicord)
• TeroDyn polymer flame spray
Cold spray equipment
• High-pressure cold spray (Kinetiks 3000)
• Low-pressure cold spray (DYMET 403K)
• Laser-assisted cold spray
Arc spray equipment
• Sulzer Metco SmartArc and 6RC
HVOFHVAF

28. Thank you for your attention