Influence of Si Surface Condition on Electroless Displacement Deposition of Pt Particles

The purpose of the study is to investigate the electrochemical behavior of two dental alloys: palladium alloy (Palidor) and Ni-Cr alloy (Verasoft) in three types of artificial saliva. Determination of corrosion potential and recording of linear and cyclic polarization curves were performed with PGP201 potentiostat (VoltaLab 21- Radelkis Copenhagen. In order to study the modifications produced on the surface of the electrodes, a complex optical microscope MC 1 research type (IOR, Romania) was used, adapted to a digital camera, which was connected to a computer for the digital acquisition of images . Two metal alloys based on Ag-Pd and Ni-Cr were used for the experiments. The materials used came from different types of dental restorations removed from the oral cavity of the patients after a 5-15 years period. As corrosion environments, three artificial saliva were used: Fusayama, Afnor and Rondelli. The Pd-Ag dental alloy exhibits a very good corrosion resistance and the treatment in the Afnor saliva does not affect the surface of the alloy. Electrochemical behavior in Fusayama-Meyer�s saliva of the alloy surface results in a series of spots representing deposits of insoluble salts resulting from the oxidation process, while in the Rondelli saliva there is a series of small corrosion points on the alloy surface. The behavior of the Verasoft alloy in the Afnor and Rondelli saliva is similar; In both solutions, the potential breakthroughs are very close, but in Fusayama-Meyer�s saliva, the potential for initiation of corrosion points is very low (206 mV), a potential that can be encountered in the oral cavity. All metals and metal alloys, even the noble and semi-precious ones, are susceptible to corrosion, forming compounds with properties different from those of the metal or base alloy, which change their surface condition. Metallic dental restorations are permanently affected by the factors of the oral environment (physical-mechanical, chemical and biological), being subjected to a continuous process of degradation.

Download Full-text

The Influence of Laser Irradiation and Ultrasound on the Structure, Surface Condition and Electrical Properties of TiS2/C Composites

Journal of Nano- and Electronic Physics ◽

10.21272/jnep.10(2).02016 ◽

2018 ◽

Vol 10 (2) ◽

pp. 02016-1-02016-5

Author(s):

I. M. Budzulyak ◽

◽

L. S. Yablon ◽

R. V. Ilnytskyi ◽

O. V. Morushko ◽

...

Keyword(s):

Electrical Properties ◽

Laser Irradiation ◽

Surface Condition ◽

Structure Surface

Download Full-text

Selective Laser Melted Titanium Alloy for Transgingival Components: Influence of Surface Condition on Fibroblast Cell Behavior

Journal of Prosthodontics ◽

10.1111/jopr.13347 ◽

2021 ◽

Author(s):

Marie‐Joséphine Crenn ◽

Aurélie Benoit ◽

Géraldine Rohman ◽

Thomas Guilbert ◽

Olivier Fromentin ◽

...

Keyword(s):

Titanium Alloy ◽

Surface Condition ◽

Fibroblast Cell ◽

Cell Behavior

Download Full-text

Stress Corrosion Cracking (SCC) of Nickel-Base Weld Metals in PWR Primary Water

Materials Science Forum ◽

10.4028/www.scientific.net/msf.747-748.723 ◽

2013 ◽

Vol 747-748 ◽

pp. 723-732 ◽

Cited By ~ 2

Author(s):

Ru Xiong ◽

Ying Jie Qiao ◽

Gui Liang Liu

Keyword(s):

Residual Stresses ◽

Stress Corrosion ◽

Stress Corrosion Cracking ◽

Surface Condition ◽

Cold Work ◽

Corrosion Cracking ◽

Pressurized Water ◽

Weld Metals ◽

Surface Residual Stresses ◽

Primary Water

This discussion reviewed the occurrence of stress corrosion cracking (SCC) of alloys 182 and 82 weld metals in primary water (PWSCC) of pressurized water reactors (PWR) from both operating plants and laboratory experiments. Results from in-service experience showed that more than 340 Alloy 182/82 welds have sustained PWSCC. Most of these cases have been attributed to the presence of high residual stresses produced during the manufacture aside from the inherent tendency for Alloy 182/82 to sustain SCC. The affected welds were not subjected to a stress relief heat treatment with adjacent low alloy steel components. Results from laboratory studies indicated that time-to-cracking of Alloy 82 was a factor of 4 to 10 longer than that for Alloy 182. PWSCC depended strongly on the surface condition, surface residual stresses and surface cold work, which were consistent with the results of in-service failures. Improvements in the resistance of advanced weld metals, Alloys 152 and 52, to PWSCC were discussed.

Download Full-text

The Surface Condition of Ni-Cr after SiC Abrasive Blasting for Applications in Ceramic Restorations

Materials ◽

10.3390/ma13245824 ◽

2020 ◽

Vol 13 (24) ◽

pp. 5824

Author(s):

Weronika Czepułkowska-Pawlak ◽

Emilia Wołowiec-Korecka ◽

Leszek Klimek

Keyword(s):

Surface Condition ◽

Abrasive Particle ◽

Surface Profile ◽

Abrasive Particles ◽

Dental Restorations ◽

Large Width ◽

Ceramic Restorations ◽

The Impact ◽

Abrasive Size ◽

Abrasive Blasting

Abrasive blasting is a process widely used in dentistry. One of the uses is the development of metal surfaces for connections with ceramics in fixed prosthetic restorations. The purpose of this paper was to check how the rough surface profile (width, height, and depth on unevenness) impacts the surface’s condition, like its wettability and percentage of stuck abrasives. The Ni-Cr alloy surface was abrasive blasted by silicon carbide with the various pressure parameters (0.2, 0.4, and 0.6 MPa) and abrasive particle sizes (50, 110, and 250 µm). Cleaned surfaces were examined for roughness, wettability, and percentage of stuck abrasive particles on the surface. The surface after abrasive blasting using 110 µm of abrasive size and 0.4 MPa pressure has the best wettability results. The width of unevenness may cause it. When the unevenness has too small or too large width and depth, the fluids may not cover the entire cavities because of locking the air. The surface condition of dental alloys directly affects metal–ceramic connection strength. The knowledge about the impact of the abrasive blasting parameters on the bond strength will allow one to create durable dental restorations.

Download Full-text