scholarly journals Influence of Titanium Surface Porosity on Adhesive Strength of Coatings Containing Calcium Silicate

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4493
Author(s):  
Ivan Zhevtun ◽  
Pavel Gordienko ◽  
Yury Kulchin ◽  
Alexander Nikitin ◽  
Dmitry Pivovarov ◽  
...  

Titanium-based alloys are widely used in aerospace engineering. They have good mechanical and corrosion properties but, in some cases, the material itself or the coating should meet some additional requirements. For example, it may be a requirement of high reflectance to provide effective temperature control. Wollastonite is a promising component for reflective coatings because it improves both their whiteness and mechanical properties. This paper presents the results of studying the composition, the structure and the adhesive strength of wollastonite-containing silicate coatings to titanium substrate. The surface of titanium samples was pre-treated by laser cladding with TiC and etching to provide surface porosity. It has been shown that such treatment allows a significantly increase in the adhesive strength of the coating to the substrate. A decrease in the adhesive strength was observed on titanium samples with an excess of TiO2 on the surface. This is caused by the formation of crystalline PbTiO3 at the interface.

2021 ◽  
Vol 27 (4) ◽  
pp. 180-184
Author(s):  
Hasan A. Fattah ◽  
Mohammed Gouda ◽  
Salah Salman ◽  
Ayman Elsayed

Magnesium is a promising lightweight metal required in many industries such as automobile, aerospace, electronics, etc. It is also a biodegradable material, which eliminates the secondary removal procedure of the implant. Furthermore, its mechanical properties are similar to the mechanical properties of human bone.  In this research, eggshells were used as an environmentally friendly composite reinforcement material in the Mg-2.5Zn-1Mn matrix. Composites were prepared using the powder metallurgy route.  The effect of eggshells on the morphology, mechanical, and corrosion behaviour of Mg-2.5Zn-1Mn alloy was investigated. The results revealed an enhancement in grain refining ability and mechanical properties of Mg-2.5Zn-1Mn with eggshell additives. The corrosion behaviour improved at a higher percentage of eggshells (10%).


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7847
Author(s):  
Viacheslav Bazhenov ◽  
Anastasia Lyskovich ◽  
Anna Li ◽  
Vasily Bautin ◽  
Alexander Komissarov ◽  
...  

Mg alloys have mechanical properties similar to those of human bones, and have been studied extensively because of their potential use in biodegradable medical implants. In this study, the influence of different heat treatment regimens on the microstructure and mechanical and corrosion properties of biodegradable Mg–Zn–Ga alloys was investigated, because Ga is effective in the treatment of disorders associated with accelerated bone loss. Solid–solution heat treatment (SSHT) enhanced the mechanical properties of these alloys, and a low corrosion rate in Hanks’ solution was achieved because of the decrease in the cathodic-phase content after SSHT. Thus, the Mg–4 wt.% Zn–4 wt.% Ga–0.5 wt.% Y alloy after 18 h of SSHT at 350 °C (ultimate tensile strength: 207 MPa; yield strength: 97 MPa; elongation at fracture: 7.5%; corrosion rate: 0.27 mm/year) was recommended for low-loaded orthopedic implants.


2017 ◽  
Vol 270 ◽  
pp. 205-211 ◽  
Author(s):  
Drahomír Dvorský ◽  
Jiří Kubásek ◽  
Dalibor Vojtěch

Magnesium and its alloys are considered for application as materials for biodegradable implants as they have mechanical properties similar to bone tissue. High demands on corrosion and mechanical properties are made on these alloys. While mechanical properties of magnesium are usually enhanced by alloying, corrosion properties may deteriorate. This paper is focused on the comparison of magnesium alloys AZ31 (3 wt. % Al, 1 wt. % Zn) and WE43 (4 wt. % Y, 3 wt. % Nd) which are considered for biomedical applications. Besides the type of alloying elements, the preparation process has also great impact on final mechanical and corrosion properties. Alloying elements may be dissolved in magnesium matrix or they can form intermetallic phases, which alter final properties. Microstructure, mechanical and corrosion properties of AZ31 and WE43 were studied and compared with pure magnesium.


2004 ◽  
Vol 467-470 ◽  
pp. 217-222 ◽  
Author(s):  
R. Badji ◽  
B. Belkessa ◽  
H. Maza ◽  
M. Bouabdallah ◽  
Brigitte Bacroix ◽  
...  

Duplex stainless steels 2205 are widely used in constructional and petrochemical applications because of their good mechanical and corrosion properties. The objective of this work was to study the influence of aging at high temperature on the austenite and d ferrite equilibrium. After welding by TIG process, duplex stainless steel was aged in the range of 800 – 1150 °C temperatures for 60 min. The microstructure was characterized by metallography and X-ray methods. The toughness of welded structure was also measured.


Author(s):  
R. Kotoka ◽  
S. Fialkova ◽  
S. Neralla ◽  
S. Yarmolenko ◽  
D. Pai ◽  
...  

In this study, Mg/SiO2 and MgO/SiO2 multilayer coatings with bilayer thicknesses (Λ) 10, 20, 40, 100, 200 and 1000 nm were deposited on glass substrates using DC and reactive pulsed DC magnetron sputtering processes. The aim of these coatings is to control the initial degradation and provide mechanical strength to magnesium implant during handling and installation. The initial thickness calibrations and deposition rates optimization were conducted using stylus profilometer. After deposition of the multilayer coatings, the values of their bilayer thicknesses (Λ) were obtained from X-ray reflectometery. The mechanical properties, surface morphology and roughness of multilayer coatings were studied using nanoindentation, SEM and AFM respectively. The nanoindentation results showed higher hardness of MgO/SiO2 multilayer coatings compared to single layer Mg. The roughness analyses showed improved roughness for bilayer thicknesses (Λ) less than 20 nm. It was observed from the SEM images that SiO2 coatings has pores. By adding Mg and/or MgO in the form of multilayers improves the pores significantly. The Mg/SiO2 multilayer coatings showed controlled degradation rate when immersed in saline solution compared to the monolithic SiO2 coating. In conclusion, conditions for depositing Mg/SiO2 and MgO/SiO2 multilayer coatings has been optimized. Alternating brittle SiO2 ceramic layers with soft and ductile Mg layers significantly improved the hardness of the Mg coating. Hardness of multilayer coatings can be fine-tuned by modifying bilayer thicknesses. Significant improvement in the corrosion and mechanical properties of the multilayer coatings can be used to protect surface of magnesium implant material during handling, storage and installation.


2019 ◽  
Vol 44 (2) ◽  
pp. 13-19
Author(s):  
Isiaka Oladele ◽  
Davies Alonge ◽  
Timothy Betiku ◽  
Abel Barnabas ◽  
S. Shittu

Experimental investigations were carried out to study the effect of weld joint designs and post weld heat treatment (PWHT) on mechanical and corrosion properties of low carbon steel. Butt, bevel and half-lap joints were produced with a voltage of 20 V and current of 110 A with the use of 3.2 mm diameter electrode E6013. Full annealing was carried out on part of the welded samples in order to consider the possibility of post weld heat treatment for better performance. The mechanical properties (tensile, hardness, and impact toughness) were studied for both the as welded (AW) and PWHT samples as well as the corrosion performance in a natural sea water environment containing 3.5 wt.% NaCl using potentiodynamic polarization method. The microstructure of the AW and PWHT samples of the welded joints with the most promising mechanical and corrosion properties were then characterized by means of an optical microscopy. The results obtained reveals that the bevel joint followed by half lap joint and the butt joint of the as weld samples gave the best combination of the mechanical properties considered. On the other hand, the corrosion properties of the butt joint were superior to that of the bevel and half lap joint, respectively in the PWHT condition as compared to the AW samples. This implies that PWHT improves the corrosion resistance of the welded steel joints.


Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3930 ◽  
Author(s):  
Jiří Kubásek ◽  
Drahomír Dvorský ◽  
Jaroslav Čapek ◽  
Jan Pinc ◽  
Dalibor Vojtěch

Zinc-based alloys represent one of the most highly developed areas regarding biodegradable materials. Despite this, some general deficiencies such as cytotoxicity and poor mechanical properties (especially elongation), are not properly solved. In this work, a Zn-5Mg (5 wt.% Mg) composite material with tailored mechanical and superior corrosion properties is prepared by powder metallurgy techniques. Pure Zn and Mg are mixed and subsequently compacted by extrusion at 200 °C and an extrusion ratio of 10. The final product possesses appropriate mechanical properties (tensile yield strength = 148 MPa, ultimate tensile strength = 183 MPa, and elongation = 16%) and decreased by four times the release of Zn in the initial stage of degradation compared to pure Zn, which can highly decrease cytotoxicity effects and therefore positively affect the initial stage of the healing process.


2012 ◽  
Vol 509 ◽  
pp. 36-39 ◽  
Author(s):  
Qiu Ming Peng ◽  
Han Wu Dong ◽  
Yong Jun Tian ◽  
Hong Jie Zhang

Mg alloys were increasingly attracting attention as a potential implant biomaterials because that there will be no need for a second surgery. However, the majority of conventional Mg alloys have been developed for automotive components and were not suitable for Mg based implants. In this paper, a new Mg-RE based materials was developed for implant biomaterials, avoiding the negative influences of previous systems. Microstructure, mechanical and corrosion properties were investigated. The result exhibited that the mechanical properties and degradable rate were sufficient to satisfy the requirement of Mg-based implants. Furthermore, the deformability of the alloy was also investigated. The fine stent pipe was prepared by cold-drawing technology. The primitive results demonstrated that this new alloy was an ideal stent materials.


2014 ◽  
Vol 52 (11) ◽  
pp. 949-956
Author(s):  
Hyunkyu Lim ◽  
Wonseok Yang ◽  
Young-Gil Jung ◽  
Shae K. Kim ◽  
Do-Hyang Kim

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