Indentation Hardness of Surface-Coated Materials

2008 ◽  
pp. 257-257-15 ◽  
Author(s):  
O Vingsbo ◽  
S Hogmark ◽  
B Jönsson ◽  
A Ingemarsson
Keyword(s):  
Indentation Hardness ◽  
Coated Materials

Graphene/chitosan/Ag+- doped hydroxyapatite triple composite fiber coatings on new generation hybrid titanium composite by electrospinning

2021 ◽  
pp. 002199832110075
Author(s):  
Tuğba Mutuk ◽  
Mevlüt Gürbüz
Keyword(s):  
Hybrid Composites ◽  
Graphene Nanosheets ◽  
Pure Titanium ◽  
Composite Fiber ◽  
Mass Change ◽  
Coated Materials ◽  
Nano Fiber ◽  
Hybrid Nanofiber ◽  
New Generation ◽  
Fiber Coatings

In this work, The hybrid hydroxyapatite (HaP), chitosan (CH) and graphene nanosheets (GNS) mixtures were applied by electrospinning on the surface of GNS and Si3N4 (SN) binary powder reinforced hybrid titanium (Ti) metal composites surface to improve composite biosurface functionallity. The surfaces of coated materials were characterized and antibacterial tests were carried on for their suitability in the industry by performing artificial body fluid tests. The hybrid nano fiber coatings formed a homogeneous structure on the composite. According to bioactivity tests and microstructure analysis, it was seen that HaP, which has the best results in the change of pH (pH= 11.80) values. The lowest mass change (0.0005 g) was observed on the 10th day of pure titanium. The highest mass change (0.0210 g) was obtained as on the HaP coated hybrid titanium composite. According to the antibacterial test result the hybrid nanofiber containing silver (Ag+) doped HaP on Ti composites showed the best antibacterial property aganist the E.coli. The fabricated electrospin coated hybrid composites can be a potantial candidate for dental, orthopedic implant applications and tissue engineering.

scholarly journals A Multilayer Functionalized Drug-Eluting Balloon for Treatment of Coronary Artery Disease

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 614
Author(s):  
Hak-Il Lee ◽  
Won-Kyu Rhim ◽  
Eun-Young Kang ◽  
Bogyu Choi ◽  
Jun-Hyeok Kim ◽  
...  
Keyword(s):  
Coronary Artery ◽  
Ex Vivo ◽  
Multilayer Coating ◽  
Balloon Catheter ◽  
Transition Time ◽  
Coating Materials ◽  
Drug Transfer ◽  
Coated Materials ◽  
Drug Loss ◽  
Drug Eluting

Drug-eluting balloons (DEBs) have been mostly exploited as an interventional remedy for treating atherosclerosis instead of cardiovascular stents. However, the therapeutic efficacy of DEB is limited due to their low drug delivery capability to the disease site. The aim of our study was to load drugs onto a balloon catheter with preventing drug loss during transition time and maximizing drug transfer from the surface of DEBs to the cardiovascular wall. For this, a multilayer-coated balloon catheter, composed of PVP/Drug-loaded liposome/PVP, was suggested. The hydrophilic property of 1st layer, PVP, helps to separate drug layer in hydrophilic blood vessel, and the 2nd layer with Everolimus (EVL)-loaded liposome facilitates drug encapsulation and sustained release to the targeted lesions during inflation time. Additionally, a 3rd layer with PVP can protect the inner layer during transition time for preventing drug loss. The deionized water containing 20% ethanol was utilized to hydrate EVL-loaded liposome for efficient coating processes. The coating materials showed negligible toxicity in the cells and did not induce pro-inflammatory cytokine in human coronary artery smooth muscle cells (HCASMCs), even in case of inflammation induction through LPS. The results of hemocompatibility for coating materials exhibited that protein adsorption and platelet adhesion somewhat decreased with multilayer-coated materials as compared to bare Nylon tubes. The ex vivo experiments to confirm the feasibility of further applications of multilayer-coated strategy as a DEB system demonstrated efficient drug transfer of approximately 65% in the presence of the 1st layer, to the tissue in 60 s after treatment. Taken together, a functional DEB platform with such a multilayer coating approach would be widely utilized for percutaneous coronary intervention (PCI).

Antimicrobial Activity of N-Halamine–Coated Materials in Broiler Chicken Houses

2018 ◽  
Vol 81 (2) ◽  
pp. 195-201 ◽  
Author(s):  
Tian Ren ◽  
Mingyu Qiao ◽  
Lei Zhang ◽  
Jean Weese ◽  
Tung-Shi Huang ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Salmonella Typhimurium ◽  
Broiler Chicken ◽  
Treated Wood ◽  
Antimicrobial Activities ◽  
Complete Inactivation ◽  
Coated Materials ◽  
Metal Aluminum ◽  
Broiler House

ABSTRACT The antimicrobial activity of 1-chloro-2,2,5,5-tetramethyl-4-imidazoidinone (MC), a nonbleaching N-halamine compound, was investigated on materials commonly used in broiler production, including stainless steel, galvanized metal, aluminum, plastic, and pressure-treated wood. MC aqueous solutions at 0.02, 0.04, and 0.06% were challenged with Salmonella Typhimurium and Campylobacter jejuni at 6 log CFU/mL, resulting in complete inactivation of both bacteria in 30 min with 0.06% MC. Follow-up experiments were performed using test materials treated with 0.1 and 1% MC and challenged with Salmonella Typhimurium and C. jejuni at 6 log CFU per coupon. Stability of MC on the various surfaces of testing materials was assessed, and the chlorine content of the materials was measured using iodometric thiosulfate titration over a 4-week period. Antimicrobial activities were evaluated by a sandwich test on each sampling day during 4 weeks of storage. On the samples treated with 1% MC, bacteria at 6 log CFU per coupon were completely inactivated within 2 h of contact time. The antimicrobial activity extended to 4 weeks, and the active chlorine atoms in the treated materials decreased from the initial 1016 to 1015 atoms per cm2. Overall, MC had high stability and long-lasting antimicrobial activity, which suggests that MC has high potential for use as a novel antimicrobial agent to lower the microbial load on broiler house materials.

scholarly journals Wear Resistance of (Ti,Al)N Metallic Coatings for Extremal Working Conditions

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 157
Author(s):  
Jarosław Mikuła ◽  
Daniel Pakuła ◽  
Ludwina Żukowska ◽  
Klaudiusz Gołombek ◽  
Antonín Kříž
Keyword(s):  
Wear Resistance ◽  
Functional Properties ◽  
Tool Life ◽  
Cutting Tools ◽  
Hard Coatings ◽  
Metallographic Analysis ◽  
Process Conditions ◽  
Tool Materials ◽  
Coated Materials ◽  
Wide Range

The article includes research results for the functional properties achieved for a wide range of sintered tool materials, including sintered carbides, cermets and three types of Al2O3 oxide tool ceramics ((Al2O3 + ZrO2, Al2O3 + TiC and Al2O3 + SiC(w)) with (Ti,Al)N coating deposited in the cathodic arc evaporation (CAE-PVD) method and comparison with uncoated tool materials. For all coated samples, a uniform wear pattern on tool shank was observed during metallographic analysis. Based on the scanning electron microscope (SEM) metallographic analysis, it was found that the most common types of tribological defects identified in tested materials are: mechanical defects and abrasive wear of the tool side, crater formation on the tool face, cracks on the tool side, chipping on the cutting edge and built-up edge from chip fragments. Deposition of (Ti,Al)N coating on all tested substrates increases the wear resistance and also limits the exceeding of critical levels of permanent stresses. It even increases the tool life many times over. Such a significant increase in tool life results, among other things, from a large increase in microhardness of PVD coated materials compared to uncoated samples, increased resistance to thermal and chemical abrasion, improved chip formation and removal process conditions. Use of hard coatings applied to sintered tool materials is considered to be one of the most important achievements in improving the functional properties of cutting tools and can still be developed by improving the coating structure solutions (sorted and nanocrystalline structures) and extending the range of coating applications (Ti,Al)N in a variety of substrates.

Strength and Adhesion of Thin Aluminum Oxide Film Deposited on Iron Surface

1993 ◽  
Vol 115 (4) ◽  
pp. 615-619 ◽  
Author(s):  
M. Nakanishi ◽  
H. Okuya ◽  
K. Nakajima
Keyword(s):  
Oxide Film ◽  
Aluminum Oxide ◽  
Substrate Surface ◽  
Iron Surface ◽  
Indentation Hardness ◽  
Aluminum Oxide Film ◽  
Thin Aluminum ◽  
Atomic Mixing ◽  
Scratch Tests ◽  
Sputter Etching

The strength of deposited film and the adhesion between the film and the substrate were investigated with deposited aluminum oxide film on iron surface by scratching the surface with a diamond cone. Two types of samples were examined, one with oxide film deposited after cleaning the substrate surface by sputter etching, the other with the film deposited without any sputter etching. It was found that a law similar to Meyers’ for indentation hardness holds between the load and scratch width on the sample examined. These results suggest that by analyzing the scratch data the adhesion strength of the film to the substrate can be estimated together with the hardness of the film itself. Analyses by EPMA (electron probe X-ray microanalyzer) and AES (Auger electron spectroscopy) were conducted to correlate the results obtained by the scratch tests and friction experiments, and it was confirmed that (i) adhesion is improved by sputter etching prior to the deposition of the film; (ii) adhesion decreases considerably due to the progress of oxidation in the vicinity of the interface, which depends markedly on the oxygen concentration in the oxide film; and (iii) there is an optimum thickness of the three-component layer (Fe, Al, and O) formed by atomic mixing at the interface for maximizing the adhesion.

Indentation hardness and fracture toughness in single crystal TiC0.96

1996 ◽  
Vol 209 (1-2) ◽  
pp. 329-336 ◽  
Author(s):  
C. Maerky ◽  
M.-O. Guillou ◽  
J.L. Henshall ◽  
R.M. Hooper
Keyword(s):  
Fracture Toughness ◽  
Single Crystal ◽  
Indentation Hardness
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