scholarly journals Salt Heat Treatment and Passivation to Improve the Corrosion Resistance of Nitinol (Ni-Ti)

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7789
Author(s):  
Inho Bae ◽  
Byung-Hoon Kim ◽  
Dong-Gon Kim ◽  
Ik-Bu Sohn ◽  
Seong-Won Yang
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Oxidation Process ◽  
Treatment Time ◽  
Niti Wire ◽  
Furnace Process ◽  
Passivation Process ◽  
Additional Process ◽  
Passivation Treatment ◽  
Scratch Tests

Corrosion of nitinol (NiTi) is a major factor in the failure of implantable materials. Recently, as the importance of corrosion of metals has increased, testing according to international guidelines is essential. The purpose of this study was to evaluate the corrosion resistance of NiTi wire through heat treatment and passivation process. In this study, NiTi wire used two commercially available products and a self-manufactured stent. Experimental consideration was carried out according to ASTM standards. Heat treatment was carried out in an air or a salt furnace, and the corrosion was measured after additional process, such as passivation and scratch tests. As a result, the metal potential was rapidly decreased in the air furnace group. On the other hand, the potential of wires was dramatically increased in the salt furnace group compared to the air furnace group. The dislocation decreased below the acceptance criteria (>600 mV) within 60 s of heat treatment time in the air furnace. Moreover, the potential was dramatically improved, even after only 20 min of passivation treatment (1076 mV, 442% compared to the non-passivated group), and it continued to rise until 180 min. This phenomenon was similarly observed in the group of self-manufactured stents. The potential slightly decreased by the scratch process (93.1%) was significantly reduced by the air furnace process (315 mV, 24.4% of the nontreated group). In the passivated group of the air furnace sample with reduced potential, the potential was restored to the level before the air furnace (scratch stage) (1032 mV). In conclusion, the heat treatment is preferably carried out in a salt furnace rather than an air furnace, and the passivation process can be an advantageous tool to improve corrosion resistance by suppressing the oxidation process.

scholarly journals Nanomechanical Behavior, Adhesion and Corrosion Resistance of Hydroxyapatite Coatings for Orthopedic Implant Applications

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 477
Author(s):  
Kaouther Khlifi ◽  
Hafedh Dhiflaoui ◽  
Amir Ben Rhouma ◽  
Joël Faure ◽  
Hicham Benhayoune ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
X Ray Diffraction ◽  
Homogeneous Microstructure ◽  
X Ray ◽  
Hydroxyapatite Coatings ◽  
Adhesion Behavior ◽  
Heat Treated ◽  
Before And After ◽  
Scratch Tests

The aim of this work was to investigate the nanomechanical, adhesion and corrosion resistance of hydroxyapatite (HAP) coatings. The electrodeposition process was used to elaborate the HAP coatings on Ti6Al4V alloy. The effect of hydrogen peroxide concentration H2O2 on the electrolyte and the heat treatment was studied. Surface morphology of HAP coatings was assessed, before and after heat treatment, by scanning electron microscopy associated with X-ray microanalysis (SEM-EDXS). Moreover, X-ray diffraction (XRD) was performed to identify the coatings’ phases and composition. Nanoindentation and scratch tests were performed for nanomechanical and adhesion behavior analysis. The corrosion resistance of the uncoated, the as-deposited, and the heat-treated coatings was investigated by electrochemical test. The obtained results revealed that, with 9% of H2O2 and after heat treatment, the HAP film exhibited a compact and homogeneous microstructure. The film also showed a crystal growth: stoichiometric hydroxyapatite (HAP) and β-tricalcium phosphate (β-TCP). After heat treatment, the nanomechanical properties (H, E) were increased from 117 ± 7 MPa and 24 ± 1 GPa to 171 ± 10 MPa and 38 ± 1.5 GPa respectively. Critical loads (LC1, LC2, and LC3) were increased from 0.78 ± 0.04, 1.6 ± 0.01, and 4 ± 0.23 N to 1.45 ± 0.08, 2.46 ± 0.14, and 4.35 ± 0.25 N (respectively). Furthermore, the adhesion strength increased from 8 to 13 MPa after heat treatment. The HAP heat-treated samples showed higher corrosion resistance (Rp = 65.85 kΩ/cm2; Icorr = 0.63 µA/cm2; Ecorr = −167 mV/ECS) compared to as-deposited and uncoated samples.

ALTEMP HX

Alloy Digest ◽  
1993 ◽  
Vol 42 (10) ◽  
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Base Alloy ◽  
Heat Treating ◽  
Nickel Base Alloy ◽  
Temperature Performance ◽  
Nickel Base

Abstract ALTEMP HX is an austenitic nickel-base alloy designed for outstanding oxidation and strength at high temperatures. The alloy is solid-solution strengthened. Applications include uses in the aerospace, heat treatment and petrochemical markets. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, and joining. Filing Code: Ni-442. Producer or source: Allegheny Ludlum Corporation.

INCO ALLOY 330

Alloy Digest ◽  
1992 ◽  
Vol 41 (5) ◽  
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Heat Treating ◽  
High Temperature Alloy ◽  
Nickel Iron ◽  
Temperature Performance ◽  
Inco Alloy ◽  
Iron Chromium

Abstract INCO ALLOY 330 is a nickel/iron/chromium austenitic alloy, not hardenable by heat treatment. It is a solid solution strengthened high-temperature alloy. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-403. Producer or source: Inco Alloys International Inc..

ALUMINUM C355.0

Alloy Digest ◽  
1983 ◽  
Vol 32 (2) ◽  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Heat Treating ◽  
Age Hardening ◽  
Casting Alloy ◽  
Permanent Mold ◽  
Good Resistance ◽  
Temperature Performance ◽  
Structural Parts ◽  
Hardening Heat Treatment

Abstract ALUMINUM C355.0 is a high-purity casting alloy that responds to an age-hardening heat treatment. It can be cast successfully by the sand and permanent-mold processes. Its castings characteristics are excellent and it is recommended for pressure-tight castings. It has good resistance to corrosion. Its applications include propeller gear boxes, crankcases and stressed structural parts in aircraft. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep and fatigue. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-243. Producer or source: Various aluminum companies.

ALUMINUM 3004

Alloy Digest ◽  
1974 ◽  
Vol 23 (4) ◽  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
High Temperature ◽  
Magnesium Alloy ◽  
Cold Working ◽  
Heat Treating ◽  
Temperature Performance ◽  
Good Workability ◽  
Manganese Magnesium

Abstract ALUMINUM 3004 is nominally an aluminum-manganese-magnesium alloy which cannot be hardened by heat treatment; however, it can be strain hardened by cold working. It has higher strength than Aluminum 3003 and good workability, weldability and resistance to corrosion. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and shear strength as well as fatigue. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-51. Producer or source: Various aluminum companies. Originally published June 1957, revised April 1974.

ALX ALLOY

Alloy Digest ◽  
1963 ◽  
Vol 12 (1) ◽  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Speed ◽  
Heat Treating ◽  
Temperature Performance ◽  
Cobalt Base

Abstract ALX is a composition of nonferrous materials with a cobalt base containing chromium, tungsten and carbon. This alloy is commonly supplied in the cast-to-shape form, having an as-cast hardness of Rockwell C60-62 and requiring no further heat treatment. ALX is also supplied as cast tool bit material and is useful where conventional high-speed steels or carbides do not function effectively. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as casting, forming, heat treating, and machining. Filing Code: Co-35. Producer or source: Allegheny Ludlum Corporation.

ALCOA 1XXX SERIES

Alloy Digest ◽  
2005 ◽  
Vol 54 (7) ◽  
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
High Purity ◽  
High Conductivity ◽  
Good Corrosion Resistance

Abstract Aluminum 1xxx series alloys are nonhardenable by heat treatment. They have high purity, high conductivity, and good corrosion resistance and are easily formed. This datasheet provides information on composition, physical properties, tensile properties, and shear strength. It also includes information on corrosion resistance as well as forming, machining, joining, and surface treatment. Filing Code: AL-395. Producer or source: Alcoa Engineered Products.

ALUMINUM 62S

Alloy Digest ◽  
1953 ◽  
Vol 2 (12) ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Corrosion Resistance ◽  
Salt Water ◽  
Heat Treating ◽  
Magnesium Silicide ◽  
Age Hardening ◽  
Aluminum Company ◽  
Wrought Aluminum ◽  
Hardening Heat Treatment

Abstract ALUMINUM 62S is a magnesium silicide type of wrought aluminum alloy with high resistance to fresh and salt water corrosion. It responds to age hardening heat treatment for high mechanical properties. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Al-11. Producer or source: Aluminum Company of America.

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