UMT TriboLab TM for Automotive Applications Suresh Kuiry, Ph.D.

Transcription

1 UMT TriboLab TM for Automotive Applications Suresh Kuiry, Ph.D.

2 Introduction Safety Energy Efficiency Environmental Concerns Innovation in Automotive 2

3 Testing Introduction Product Differentiation Extent of Value- addition Comparative Data Automakers Research Organizations Part Suppliers INNOVATION in Automotive Bruker s UMT TriboLab 3

4 UMT TriboLab Applications Numerous Automotive components can be tested for their Quality and Performance using UMT TriboLab system - a few examples: Paints and coating (Scratch, Hardness) Lubricants (Comparative Stribeck Curves) Clutch and brake materials (Friction, Wear) Bearing (Wear) Tires (Friction, Wear) Piston ring and cylinder liner (Friction, Wear) Elastomers (Shore Hardness, Mechanical Properties) Engine valve (Hot Hardness) Wind shield (Scratch/Mar Resistance) Mirror (Stiction, Scratch Resistance) 4

5 Test Methods Tribological Friction (Static, Dynamic, Stiction) Wear and Wear Durability Mechanical Hardness (Classical and Instrumented methods) Young s modulus (instrumented indentation) Flexural stress-strain and elasticity in bending Scratch Test (Adhesion and Mar Resistance) 5

6 Bruker s UMT TriboLab o The system is built on the Universal Mechanical Test (UMT) platform with precision control of load, speed, and position. o Most sophisticated and versatile tribology test system ever designed Modular and Innovative Broadest Capabilities Unmatched Ease of use o Real Time Control and Data Analysis software to ensure high accuracy and repeatability of test data. 6

7 Precision Base-ring Bruker s UMT TriboLab Modular and Innovative Design ensures the maximum flexibility - Single motor to cover full torque and speed ranges - Easy to configure for any tribological or mechanical tests - Interchangeable lower drives Broadest Capabilities Tool-less Clamping - Force (1mN to 2kN) - Torque (up to 5N m) - Speed (0.1 to 5000 rpm) - Temperature (-30 to 1000 o C) - Humidity (5 to 85%RH) TriboID Chip Blind-mate Electrical Connecters Self-centering Coupler 7

8 Bruker s UMT TriboLab Unmatched Ease of Use due to Intelligent hardware and software interfaces making it user-friendly, versatile, and productive. - TriboID TM automatically detects and configures components that are plugged into the TriboLab system - Triboscript TM offers an enhanced and secured scripting interface with Operator and Expert Modes of scripting environment for running test at ease vis-a-vis preserving the universality towards advanced test script development using test-block methodology. 8

9 UMT TriboLab Drives 9

10 Liquid and Environmental Chambers Rotary Liquid Chamber Rotary Heating Chamber Rotary Humidity Chamber BOR Heating Chamber 10

11 Friction Test Friction: The resistance force that one surface or object encounters when moving over another. o Sledge Friction Test (flat-on-flat) (ASTM D1894) o Ball-on flat, Pin-on-flat, cylinder-on-flat Fz Fx Sliding COF( ) F F X Z mg tan 11

12 Sledge Friction Fz Static Fx Sliding Dynamic Sliding Distance Static and dynamic friction of solid surfaces 12

13 Lubricant Test: Stribeck Curve Stribeck curve Piston Ring Engine Bearing Boundary Mixed Hydrodynamic Cam and Follower to evaluate lubricants for their potential applications and comparison (ranking) UMT TriboLab can cover all three regions in wide ranges of force, speed, and temperatures Stribeck Curve of Lube A with ECR 13

14 Comparative Stribeck Curves Boundary Mixed Hydrodynamic Stribeck curves of Lubes A and B showing differences in Boundary and Mixed regimes 14

15 Wear Durability Test Testing tool tip ball, Rockwell diamond stylus Special probes such as ECR and AE measurements 15

16 Wear Durability Test of Paints Wear Durability test results on painted panels using ECR option. 16

17 Wear Test Thrust Washer (ASTM D3702-Ring-on-disk) Test is designed for the evaluation of wear of bulk materials but this procedure can also be used for measurement of wear resistance of a coating. Fz and Torque (Tz) are measured to obtain the evolution of COF as function of Time. Fz Specific wear rate as the amount of materials removed (mm 3 ) with unit force (N) and unit relative distance (m) travelled by the wearing contact. The specific wear rate is expressed in mm3 N.m unit. 17

18 Wear Test of Coating Test: 20 N, 300 rpm, 1 hr Sp. Wear Rate = 6.85 x 10-5 mm3 N.m 18

19 Constant Velocity Spiral Wear Test X 19

20 Piston Ring Cylinder Liner Test (ASTM G181 ) Step loading N and back; Frequency-10Hz; Stroke-10mm 20

21 Bearing Test with Conformal Contact Conformal bearing test (BOR type drive): 2kN, 500 rpm; hot oil recirculation; Torque measured with an inline torque sensor 21

22 Hardness Test Hardness indicates the resistance of a material against plastic deformation. Hardness Tests: Brinell, Vickers, Knoop, Rockwell, and Shore Instrumented Indentation Test: hardness and Young s modulus from load-displacement data 22

23 Brinell, Vickers, Knoop Hardness Brinell hardness (HB): HB = 2F z πd D D 2 d 2 F Z is in kgf, D and d are in mm. F z D d Vickers hardness (HV): HV = 2F zsin α 2 d 2 F Z is in kgf, = 136 ; d = (d 1 +d 2 )/2 in mm. d 2 d 1 Knoop hardness (HK): HK = F z d 2 F Z is in kgf, d is the long diagonal in mm. d 23

24 Rockwell and Shore Hardness Rockwell hardness test applies an initial load (F Minor ), increased to a final value (F Major ), then load is reduced to the initial value. The difference in tip displacement between two such minor loads relates inversely to the hardness of specimen. Hardness (H): H = k z. z F Minor F Major F Minor Example: Hardness measurement in Rockwell C scale: F Minor = 10 kgf; F Major = 150 kgf; H = HRC; k = 100; z = permanent tip displacement of diamond indenter in unit of 2 m. Shore hardness follows similar principle as Rockwell, but it differs in load levels, tip materials, and geometry. It is primarily used for soft materials such as elastomers. 24

25 Hot Hardness Hot hardness refers to the hardness of materials at elevated temperatures. Hardness reflects the strength of materials that decreases with rise in temperature. Mechanical strength of Materials at High temperature is an important design parameter. AISI 347 Stainless Steel Usually high temperature mechanical properties of any materials are evaluated by mechanical and creep rupture tests at elevated temperatures. These tests are inherently time-consuming and difficult. Hot hardness test using UMT TriboLab is a faster alternative. UMT TrboLab has capability of high temperature test up to 1000 C. Engine valve materials can be evaluated by measuring its hot hardness. 25

26 Instrumented Indentation (Oliver-Pharr) E = 178.3±3.6 GPa H = 13.2 ±0.4 GPa Load vs. Displacement Plots Force (Fz) vs. Displacement (h): F B( h ) dfz Contact Stiffness (S): S h mb( h max dh FZ max Contact Depth (h c ): hc hmax S Contact Area (A): A f h ) ( c Z h f FZ max Hardness (H): H A S Reduced Elastic Modulus (E r ): E r 2 Elastic Modulus (E) of the specimen is 2 2 calculated using: i E E E r i m m 1 max h f ) where, and i are the Poisson s ratios of the specimen and the indenter, respectively; E i is elastic modulus of the indenter A 26

27 Three-point Bend Test F Z ASTM D790 and ISO:178 L 2 L 2 b d Flexural Stress (σ f )= 3F ZL 2bd 2 ; Flexural Strain (ε f ) = 6Dd L 2 where, F Z is the force applied; L is the support span Modulus of elasticity in bending (E B ) = L3 m 4bd 3 b and d are the width and the depth of the beam, respectively. D is the maximum deflection at the center of the beam m is the slope of the initial straight line portion of F Z vs. D plot 27

28 Three-point Bend Test Fz vs. Z plot of a polymer specimen during 3-point bend test 28

29 Three-point Bend Test σ f = 86 MPa ε f = E B = 1.25 GPa Flexural Stress vs. Flexural Strain of the polymer specimen 29

30 Three-point Bend Test Fz vs. Z plot of a ceramic specimen during 3-point bend test 30

31 Three-point Bend Test σ f = 98 MPa ε f = E B = 13.9 GPa Flexural Stress vs. Flexural Strain of the ceramic specimen 31

32 Automotive Paints and Coatings Top Clear Coat (50 m) Base Coat (20 m) Primer (25 m) Electrocoat (25 m) Phosphate Layer (1 m) Substrate Typical Paint System on an Auto body Paint is relatively thick. Its primary function is to prevent materials degradation such as corrosion and improve aesthetic. Coating is relatively thin and it is used for enhancing the tribological properties such as friction, wear, and scratch resistance of components. Paints and coating can be evaluated by scratch test. 32

33 Scratch Test Capabilities o o o o o o o o Fully conform to ASTM C1624 Wide force and velocity ranges for scratching Zoom-in option on the scratch image Image marker to measure scratch dimensions All four (X+, X-, and Y+ and Y-) directional scratching Automated positioning, focusing, and imaging of the scratch Advanced scratch-imaging options to display and saving of scratch Image with force, AE, ECR, and depth profile data Can accommodate scratch tool such as diamond stylus, Vickers, etc. o Automatic tilt adjustment during scratch depth profile calculation 33

34 Scratch Tests (a) (b) (c) (d) (a) Load and (b) scratch width profiles of a Linear scratch; (c) Load and (d) scratch width profiles of a Zigzag scratch. 34

35 Scratch Tests (a) (b) (c) (d) (a) Load and (b) scratch width profiles of a Unidirectional scratch; (c) Load and (d) scratch width profiles of a X-Y scratch. 35

36 Scratch Adhesion Test of Coating Scratch Adhesion Scratched Scratch test results on painted panels using AE and ECR 36

37 Comparative Mar Resistance Scratch test results using Vickers: Bare Glass A Mar Resistance: 100 mn 37

38 Comparative Mar Resistance Scratch test results using Vickers: Bare Glass B Mar Resistance: 54 mn 38

39 Scratch Test with Depth Profile (Prescan-Scratch-Postscan) Scratch test results on DLC-coating with a diamond stylus 39

40 Scratch Test with Depth Profile (Prescan-Scratch-Postscan) Raw-depth profiles of Prescan, Scratch, and Postscan using a Cap sensor for depth measurements 40

41 Scratch Test with Depth Profile (Prescan-Scratch-Postscan) Levelled-depth profiles of Prescan, Scratch, and Postscan using a Cap sensor for depth measurements 41

42 Scratch Test with Depth Profile (Prescan-Scratch-Postscan) Relative-Scratch depth profiles of Prescan, Scratch, and Postscan using a Cap sensor for depth measurements 42

43 Summary o R & D activities are being vigorously pursued by automobile manufacturers, academia related to automotive, and auto venders to stand out in the extremely competitive and dynamic global market. Testing of auto-components for their quality is a very important activity. UMT TriboLab is leading in such applications effectively. o UMT TriboLab TM is built as a universal test system on the concept of modular and innovative design that covers wide ranges of test parameters and environmental conditions. o Integration of Intelligent hardware and software interfaces makes it extremely user-friendly, most versatile, and very productive tool for performing tribological and mechanical tests. 43

44 Thank you! January 21,