Effects of substrate constraint on micro-indentation testing of polymer coatings

2005 ◽  
Vol 396 (1-2) ◽  
pp. 77-86 ◽  
Author(s):  
Y.C. Lu ◽  
D.M. Shinozaki
Keyword(s):  
Polymer Coatings ◽  
Indentation Testing ◽  
Micro Indentation ◽  
Substrate Constraint

Identification of local constitutive model from micro-indentation testing

2011 ◽  
pp. 177-182 ◽  
Author(s):  
Y Marco ◽  
V Le Saux ◽  
G Bles ◽  
S Calloch ◽  
P Charrier
Keyword(s):  
Constitutive Model ◽  
Indentation Testing ◽  
Micro Indentation

scholarly journals UHMWPE Nanocomposite Coatings Reinforced with Alumina (Al2O3) Nanoparticles for Tribological Applications

Coatings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 280 ◽  
Author(s):  
Abdul Mohammed
Keyword(s):  
Normal Load ◽  
Polymer Nanocomposite ◽  
Polymer Coatings ◽  
Nanocomposite Coating ◽  
Efficient Solutions ◽  
Al2o3 Nanoparticles ◽  
Wear Life ◽  
Wear And Tear ◽  
Stainless Steel Ball ◽  
Micro Indentation

Due to a growing demand for protecting metallic components from wear and tear, polymer coatings are being extensively researched and developed as one of the most effective and efficient solutions to reduce friction and wear in demanding tribological applications. The present study focuses on developing a polymer nanocomposite coating of ultra-high molecular polyethylene (UHMWPE) reinforced with different loadings (0.5, 3, 5, and 10 wt %) of alumina to protect steel surfaces. Wear tests were conducted on the coated samples using a tribometer with a ball-on-disk configuration, sliding against a 440C hardened stainless steel ball as a counterface to evaluate the wear life and the load-bearing capacity of the developed coatings. Micro-indentation, energy dispersive X-ray spectroscopy, scanning electron microscopy, and optical profilometry techniques were used to characterize the coatings in terms of hardness, dispersion of the nanofillers, morphology, and wear mechanisms, respectively. Results showed that the UHMWPE nanocomposite coating reinforced with 3 wt % and 5 wt % of alumina did not fail, even until 250,000 cycles at a normal load of 12 N and a linear speed of 0.1 m/s, showing a significant improvement in wear resistance as compared to the pristine UHMWPE coating.

Compressive Properties of Mouse Articular Cartilage Determined in a Novel Micro-Indentation Test Method and Biphasic Finite Element Model

2006 ◽  
Vol 128 (5) ◽  
pp. 766-771 ◽  
Author(s):  
Li Cao ◽  
Inchan Youn ◽  
Farshid Guilak ◽  
Lori A Setton
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Articular Cartilage ◽  
Indentation Test ◽  
Small Animal ◽  
Element Model ◽  
Indentation Testing ◽  
Compressive Properties ◽  
Biphasic Finite Element ◽  
Micro Indentation

The mechanical properties of articular cartilage serve as important measures of tissue function or degeneration, and are known to change significantly with osteoarthritis. Interest in small animal and mouse models of osteoarthritis has increased as studies reveal the importance of genetic background in determining predisposition to osteoarthritis. While indentation testing provides a method of determining cartilage mechanical properties in situ, it has been of limited value in studying mouse joints due to the relatively small size of the joint and thickness of the cartilage layer. In this study, we developed a micro-indentation testing system to determine the compressive and biphasic mechanical properties of cartilage in the small joints of the mouse. A nonlinear optimization program employing a genetic algorithm for parameter estimation, combined with a biphasic finite element model of the micro-indentation test, was developed to obtain the biphasic, compressive material properties of articular cartilage. The creep response and material properties of lateral tibial plateau cartilage were obtained for wild-type mouse knee joints, by the micro-indentation testing and optimization algorithm. The newly developed genetic algorithm was found to be efficient and accurate when used with the finite element simulations for nonlinear optimization to the experimental creep data. The biphasic mechanical properties of mouse cartilage in compression (average values: Young’s modulus, 2.0MPa; Poisson’s ratio, 0.20; and hydraulic permeability, 1.1×10−16m4∕N‐s) were found to be of similar orders of magnitude as previous findings for other animal cartilages, including human, bovine, rat, and rabbit and demonstrate the utility of the new test methods. This study provides the first available data for biphasic compressive properties in mouse cartilage and suggests a promising method for detecting altered cartilage mechanics in small animal models of osteoarthritis.

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