The Heat Treatment Characteristics of Hydroxyapatite Thin Films Deposited by RF Sputtering

2007 ◽  
Vol 124-126 ◽  
pp. 1433-1436
Author(s):  
Chan Hoi Jung ◽  
Soon Kook Kim ◽  
Chang Woo Jang ◽  
Jun Hee Lee ◽  
Su Ho Lee ◽  
...  

RF sputtering process was applied to produce thin hydroxyapatite(HAp, Ca10(PO4)6(OH)2) films on Ti-6Al-4V alloy substrates. The effects of different heat treatment conditions on the bonding strength between HAp thin films and Ti-6Al-4V alloy substrates were studied. Before deposition, the Ti-6Al-4V alloy substrates were heat treated for 1hr at 850°C under 3.0×10-3torr, and after deposition, the HAp thin films were heat treated for 1hr at 400°C, 600°C and 800°C under the atmosphere, and analyzed optical microscope, FESEM, FTIR, XRD, nano-indentor, micro-vickers hardness, respectively. Experimental results represented that the HAp thin films on the heat treated substrates had higher hardness than none-heat treated substrates before the deposition.

Author(s):  
Chan Hoi Jung ◽  
Soon Kook Kim ◽  
Chang Woo Jang ◽  
Jun Hee Lee ◽  
Su Ho Lee ◽  
...  

2006 ◽  
Vol 16 (4) ◽  
pp. 218-224
Author(s):  
Chan-Hoi Jung ◽  
Jun-Hee Lee ◽  
Youn-Hak Shin ◽  
Myung-Han Kim ◽  
Sock-Hwan Choi ◽  
...  

2013 ◽  
Vol 554-557 ◽  
pp. 1856-1863 ◽  
Author(s):  
Shohei Kajikawa ◽  
Takashi Iizuka

In this study, we investigated changes in the injectability of bamboo powder and the Vickers hardness of compacted products resulting from differences in heat-treatment conditions such as steaming and boiling. We conducted injection tests and test fabrications of compacted products using bamboo powder treated under various conditions. From the injection tests of heat-treated bamboo powder, we found that injectability was improved by heat treatment. While bamboo powder steamed at 200 °C showed good injectability, boiling at 200 °C yielded better injectability. Vickers hardness tests conducted on compacted products showed that hardness was increased by heat treatment under appropriate conditions. In addition, we found that the heat-treatment condition required to increase the hardness of product was different from that needed to improve injectability.


Author(s):  
Abhijit Biswas ◽  
Suman Kalyan Das ◽  
Prasanta Sahoo

The microstructural changes of electroless Ni–P–Cu coating at various heat-treatment conditions are investigated to understand its implications on the tribological behavior of the coating. Coatings are heat-treated at temperatures ranging between 200°C and 800 °C and for 1–4 h duration. Ni–P–Cu coatings exhibit two-phase transformations in the temperature range of 350–450 °C and the resulting microstructural changes are found to significantly affect their thermal stability and tribological attributes. Hardness of the coating doubles when heat-treated at 452 °C, due to the formation of harder Ni3P phase and crystalline NiCu. Better friction and wear performance are also noted upon heat treatment of the coating at the phase transformation regime, particularly at 400 °C. Wear mechanism is characterized by a mixed adhesive cum abrasive wear phenomena. Heat treatment at higher temperature (600 °C and above) and longer duration (4 h) results in grain coarsening phenomenon, which negatively influences the hardness and tribological characteristics of the coating. Besides, diffusion of iron from the ferrous substrate as well as greater oxide formation are noticed when the coating is heat-treated at higher temperatures and for longer durations (4 h).


2007 ◽  
Vol 336-338 ◽  
pp. 505-508
Author(s):  
Cheol Jin Kim ◽  
In Sup Ahn ◽  
Kwon Koo Cho ◽  
Sung Gap Lee ◽  
Jun Ki Chung

LiNiO2 thin films for the application of cathode of the rechargeable battery were fabricated by Li ion diffusion on the surface oxidized NiO layer. Bi-axially textured Ni-tapes with 50 ~ 80 μm thickness were fabricated using cold rolling and annealing of Ni-rod prepared by cold isostatic pressing of Ni powder. Surface oxidation of Ni-tapes were conducted using tube furnace or line-focused infrared heater at 700 °C for 150 sec in flowing oxygen atmosphere, resulted in NiO layer with thickness of 400 and 800 μm, respectively. After Li was deposited on the NiO layer by thermal evaporation, LiNiO2 was formed by Li diffusion through the NiO layer during subsequent heat treatment using IR heater with various heat treatment conditions. IR-heating resulted in the smoother surface and finer grain size of NiO and LiNiO2 layer compared to the tube-furnace heating. The average grain size of LiNiO2 layer was 0.5~1 μm, which is much smaller than that of sol-gel processed LiNiO2. The reacted LiNiO2 region showed homogeneous composition throughout the thickness and did not show any noticeable defects frequently found in the solid state reacted LiNiO2, but crack and delamination between the reacted LiNiO2 and Ni occurred as the reaction time increased above 4hrs.


2021 ◽  
Vol 875 ◽  
pp. 203-210
Author(s):  
Talha Ahmed ◽  
Wali Muhammad ◽  
Zaheer Mushtaq ◽  
Mustasim Billah Bhatty ◽  
Hamid Zaigham

In this study, mechanical properties of friction stir welded Aluminum Alloy (AA) 6061 in three different heat treatment conditions i.e. Annealed (O), Artificially aged (T6) and Post Weld Heat Treated (PWHT) were compared. Plates were welded in a butt joint form. Parameters were optimized and joints were fabricated using tool rotational speed and travel speed of 500 rpm and 350 mm/min respectively. Two sets of plates were welded in O condition and out of which one was, later, subjected to post weld artificial aging treatment. Third set was welded in T6 condition. The welds were characterized by macro and microstructure analysis, microhardness measurement and mechanical testing. SEM fractography of the tensile fracture surfaces was also performed. Comparatively better mechanical properties were achieved in the plate with PWHT condition.


2020 ◽  
Vol 67 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Anasyida Abu Seman ◽  
Ji Kit Chan ◽  
Muhammad Anas Norazman ◽  
Zuhailawati Hussain ◽  
Dhindaw Brij ◽  
...  

Purpose This paper aims to investigate the corrosion behaviour of heat-treated and cryorolled Al 5052 alloys in different Cl− ion concentrations. Design/methodology/approach NaCl solutions with concentrations of 0, 0.5, 3.5 and 5.5 per cent were selected. Samples were subjected to pre-heat treatment (annealing at 300 °C and solution treatment at 540 °C) and cryorolling up to 30 per cent reduction before undergoing corrosion tests. The corrosion behaviour of the samples was then investigated by potentiodynamic polarization. The microstructure of the corroded samples was evaluated under an optical microscope, and the percentages of pits on their surfaces were calculated. Findings The cryorolled samples had a lower corrosion rate than the samples that were not cryorolled. The cryorolled sample that underwent solution treatment showed the highest corrosion resistance among all the samples tested. Practical implications The commercial impact of the study is the possibility of using the cryorolled Al alloy in various ion chloride environment. Originality/value The obtained results help in understanding the corrosion behaviour of cryorolled samples under different heat treatment conditions.


1995 ◽  
Vol 10 (9) ◽  
pp. 2271-2276 ◽  
Author(s):  
V. Pierre ◽  
D. Pierre ◽  
A.C. Pierre

New materials were made by infiltration of sol-gel boehmite thin films with copper acetate. The structure and phase transformation of these materials during heat treatment were studied. It was found that infiltration in the boehmite state did not end up in the same material as direct infiltration in the θ-alumina derived from boehmite, even after both types of materials were heat-treated at 900 °C. Infiltration in boehmite makes it possible to synthesize sandwich structures comprised of alternate layers of CuO and of γ-alumina.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Vlatka Jirouš-Rajković ◽  
Josip Miklečić

Heat treatment is a method of wood modification with increasing market acceptance in Europe. The major patented European commercial heat treatment processes have trade names ThermoWood, Platowood, Retiwood, Le Bois Perdure, and Oil-Heat-Treated Wood (OHT). To what extent modification of wood affects the resistance of wood to weathering is also an important aspect for wood applications, especially where appearance is important. Unfortunately, heat-treated wood has poor resistance to weathering, and surface treatment with coatings is required for both protection and aesthetic reasons. As a substrate for coating, heat-treated wood has altered characteristics such as lower hygroscopicity and liquid water uptake and changed acidity, wettability, surface free energy, and anatomical microstructure. Various wood species, heat treatment method, treatment intensity, and treatment conditions exhibited a different extent of changes in wood properties. These altered properties could affect coating performance on heat-treated wood. The reported changes in acidity and in surface energy due to heat treatments are inconsistent with one another depending on wood species and temperature of the treatments. This paper gives an overview of the research results with regards to properties of heat-treated wood that can affect coating performance and weathering of uncoated and coated heat-treated wood.


2012 ◽  
Vol 26 (31) ◽  
pp. 1250137 ◽  
Author(s):  
M. AMIRHOSEINY ◽  
Z. HASSAN ◽  
S. S. NG ◽  
L. S. CHUAH ◽  
M. A. AHMAD ◽  
...  

We have fabricated photoconductors of indium nitride (InN) grown by radio frequency (RF) sputtering. The InN thin films were deposited on Si (100), Si (110) and Si (111) substrates at room temperature. The Ag/Al contact has been deposited by thermal evaporation in vacuum (10-5 Torr ) and then annealed under the flowing of the nitrogen gas environment in order to relieve stress and also induce any favorable reactions between metals and the semiconductor. Current–voltage (I–V) measurements after heat treatment at 400°C were carried out for samples in dark and illumination conditions. It was found that Ag/Al formed a good ohmic contact on top of InN . In addition, the characteristics of the contacts were significantly affected by the orientation of substrates.


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