Role of polymorph microstructure of Ti6Al4V alloy on PEO coating formation in phosphate electrolyte

The titanium Ti6Al4V alloy has excellent properties, and is one of the most important and widely used metal materials in the field of modern high-tech. Selective laser melting (SLM) is an ideal process for the rapid prototyping of Ti6Al4V alloy components with complex structures, but the performances need to be further improved. In this paper, the relative density, hardness, and microstructure under different scanning conditions were first analyzed in order to clarify the role of rescanning process in improving the performances. Then, the effects of different scanning strategies on the residual stress were analyzed. The results show that the strategy of partition rescanning has the most significant effect on residual stress. Finally, the SLM experiments of aviation nozzle rings were carried out. The results show that the average residual stress of the Re-SLMed sample was reduced from 322 MPa to 254 MPa.

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Threshold Value of Particle Concentration in EPD: Experimental Evidence with TiO2 Organic Suspensions

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.412.51 ◽

2009 ◽

Vol 412 ◽

pp. 51-56 ◽

Cited By ~ 3

Author(s):

Simona Radice ◽

Stefano Mischler ◽

Johann Michler

Keyword(s):

Particle Concentration ◽

Deposition Time ◽

Threshold Value ◽

Deposition Process ◽

Suspension Systems ◽

Limit Value ◽

Coating Formation ◽

Concentration Threshold

This study was triggered by our experience on electrophoretic deposition (EPD) with different suspension systems showing evidence of a particle concentration threshold, below which no deposit was formed. In this study, the role of particle concentration in the mechanism of EPD was investigated with a model system, consisting of isopropanol suspensions with TiO2 nanosized particles (d50 = 130 nm). The investigated concentration range was 0.01 - 0.4 vol% TiO2. Constant voltage EPD tests with variable particle concentration were performed for 1 min under different applied voltages (25 - 300 V corresponding to 62.5 - 750 V/cm). A longer deposition time (30 min) was tested for a lower concentration value (0.003 vol% TiO2). The deposition process was evaluated in situ by means of the current measured during EPD. The deposits obtained were characterized by weight and profile measurements and scanning electron microscope (SEM). The results confirmed the finding of a lower limit value of particle concentration, determining a threshold in the formation of an EPD coating. Above this threshold, proportionality between deposited mass and particle concentration was observed, in agreement with the equation of Hamaker. Below this threshold, the proportionality was lost with evidence of a lack of coating formation. A possible interpretation for this experimental finding was provided.

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Role of sintering and clay particle additions on coating formation during PEO processing of AM50 magnesium alloy

Surface and Coatings Technology ◽

10.1016/j.surfcoat.2012.10.013 ◽

2012 ◽

Vol 213 ◽

pp. 48-58 ◽

Cited By ~ 41

Author(s):

Carsten Blawert ◽

Santosh Prasad Sah ◽

Jun Liang ◽

Yuanding Huang ◽

Daniel Höche

Keyword(s):

Magnesium Alloy ◽

Clay Particle ◽

Coating Formation

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The role of oxidative stress in pro-inflammatory activation of human endothelial cells on Ti6Al4V alloy

Biomaterials ◽

10.1016/j.biomaterials.2013.07.030 ◽

2013 ◽

Vol 34 (33) ◽

pp. 8075-8085 ◽

Cited By ~ 22

Author(s):

Roman Tsaryk ◽

Kirsten Peters ◽

Susanne Barth ◽

Ronald E. Unger ◽

Dieter Scharnweber ◽

...

Keyword(s):

Oxidative Stress ◽

Endothelial Cells ◽

Ti6al4v Alloy ◽

Human Endothelial Cells ◽

Inflammatory Activation

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Friction/Wear Behaviors of Magnetron Sputtered TiB2-C Composite Films on Ti6Al4V Alloy Substrate

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.189-193.979 ◽

2011 ◽

Vol 189-193 ◽

pp. 979-982

Author(s):

Xiao Jing Xu ◽

Xin Lan Sheng ◽

Dan Chen ◽

Xi Ling Xin ◽

Kun Tian ◽

...

Keyword(s):

Room Temperature ◽

Composite Films ◽

Ti6al4v Alloy ◽

Wear Properties ◽

Microstructural Characteristics ◽

Carbon Doped ◽

Alloy Substrate ◽

Sic Films ◽

Ball On Disc

The microstructure and friction/wear properties of TiB2-C (carbon-doped TiB2) films in TiB2-C/SiC double layer films (SiC films as interlayer) deposited on Ti6Al4V alloy substrate using magnetron sputtering technique at room temperature were investigated. The results show that the TiB2-C films exhibited the microstructural characteristics with nano-scale particles (domains), and the doped-carbon presented in manner of sp3 C-C and sp2 C-C bonds i.e. DLC (diamond-like carbon). The interface between the substrate and the SiC films and the interface between the SiC films and the TiB2-C composite films both showed good adhesion, with obvious element diffusions. As sliding against Si3N4 (silicon nitride) balls (2 mm in radius) using ball-on-disc type wear tester at room temperature under Kokubo simulation body fluid (SBF) and 50g load, the TiB2 -C composite films exhibited the friction coefficient of about 0.14 and the specific wear rate of 10.710-6 mm3 m−1 N−1. It is believed that the superior friction properties of the TiB2-C films are due to the role of the doped-carbon.

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Promoted Anodizing Reaction and Enhanced Coating Performance of Al–11Si Alloy: The Role of an Equal-Channel-Angular-Pressed Substrate

Materials ◽

10.3390/ma12193255 ◽

2019 ◽

Vol 12 (19) ◽

pp. 3255 ◽

Cited By ~ 1

Author(s):

Zhou ◽

Song ◽

Liang ◽

Jiang ◽

Gao ◽

...

Keyword(s):

Corrosion Resistance ◽

Comparative Study ◽

Crystal Defects ◽

Coated Sample ◽

Coating Performance ◽

Uniform Coating ◽

Ecap Process ◽

Coating Formation ◽

Anticorrosion Performance

In this paper, the effect of the equal-channel-angular-pressed (ECAPed) substrate on the coating formation and anticorrosion performance of the anodized Al–11Si alloy was systematically investigated. The ECAP process dramatically refines both Al and Si phases of the alloy. The parallel anodizing circuit is designed to enable a comparative study of anodizing process between the cast and the ECAPed alloys by tracking their respective anodizing current quota. The optimum coatings of both alloys were obtained after anodization for 30 min. The ECAPed alloy attained a thicker, more compact, and more uniform coating. Energetic crystal defects in the fine Al grains of the ECAPed substrate promote the anodizing reaction and lead to the thicker coating. Fragmented and uniformly distributed fine Si particles in the ECAPed alloy effectively suppress the coating cracks, enhancing the compactness of the coating. Overall, the ECAP-coated sample exhibits the best anticorrosion performance, which is evidenced by the concurrently enhanced prevention of coating and improved corrosion resistance of the substrate.

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