Fabrication, characterization, and in vivo biocompatibility evaluation of titanium-niobium implants

2020 ◽  
Vol 235 (1) ◽  
pp. 99-108
Author(s):  
Abdurrahman Yolun ◽  
Murat Şimşek ◽  
Mehmet Kaya ◽  
Ebru Elibol Annaç ◽  
Mustafa Köm ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Powder Metallurgy ◽  
Toxic Effect ◽  
Sintering Temperature ◽  
Transformation Temperatures ◽  
Nb Content ◽  
Orthopedic Applications ◽  
Powder Metallurgy Methods

In this study, biocompatible titanium-niobium (Ti-Nb) alloys were fabricated by using powder metallurgy methods. Physical, morphological, thermal, and mechanical analyses were performed and their in vivo compatibility was evaluated. Besides α, β, and α″ martensitic phases, α+β Widmanstätten phase due to increasing sintering temperature was seen in the microstructure of the alloys. Phase transformation temperatures of the samples decreased as Nb content increased. The ratio of Nb in the samples affected their mechanical properties. No toxic effect was observed on implanted sites. This study shows that Ti-Nb alloys can be potentially used for orthopedic applications without any toxic effects.

Effect of Processing Parameters on Mechanical Properties of Al7175/Boron Carbide (B4C) Composite Fabricated by Powder Metallurgy Techniques

2021 ◽  
Vol 105 ◽  
pp. 8-16
Author(s):  
Guttikonda Manohar ◽  
Krishna Murari Pandey ◽  
Saikat Ranjan Maity
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Powder Metallurgy ◽  
Sintering Temperature ◽  
Processing Parameters ◽  
Matrix Composites ◽  
Composite Powders ◽  
Porosity Level ◽  
Milling Operations ◽  
Boron Carbide B4c

Metal matrix composites attain a significant position in Industrial, defense, structural and automobile applications. To amplify that strategy there is a need to find out the conditional behavior of the composites and enhancing the properties will be mandatory. The present work mainly investigates on the effect of processing parameters like densification rates, sintering temperature, reinforcement content on the microstructure, mechanical properties of the Al7175/B4C composite material fabricated by mechanical milling and powder metallurgy techniques. Results show there is a grain size reduction and refinement in the composite material through ball milling operations and along with that increasing B4C content in the composite powders make milling conditions very effective. Increasing the sintering temperature results in a consistent grain growth along with that porosity level decreases up to a limit and then attain a steady state, the strength of the composites increases with compaction pressures but reinforcements content effects the strength of the material by losing its ductility making it brittle.

Effects of SiO2 Particles in Mechanical Properties of Iron Composite

2013 ◽  
Vol 465-466 ◽  
pp. 886-890
Author(s):  
Adibah Amir ◽  
Othman Mamat
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Fine Particles ◽  
Sintering Temperature ◽  
Silica Particles ◽  
Milling Process ◽  
Powder Metallurgy Technique ◽  
Temperature Changes ◽  
Different Temperatures

Tronohs raw sand was converted into fine silica particles via a series of milling process. Addition of these fine particles into iron composite was found to modify its mechanical properties. The composite was prepared using powder metallurgy technique with varying percentage of silica particles; 5, 10, 15, 20 and 25wt%. The composites were sintered at three different temperatures; 1000° C, 1100° C and 1200° C to find the most suitable sintering temperature. Changes in density and hardness were observed. The results showed that composite consist of 20wt% silica particles and sintered at 1100° C exhibits best improvement.

scholarly journals The effect of milling time on the alumina phase transformation in the AMCs powder metallurgy reinforced by silica-sand-tailings

2022 ◽  
pp. 103-117
Author(s):  
Sukanto ◽  
Wahyono Suprapto ◽  
Rudy Soenoko ◽  
Yudy Surya Irawan
Keyword(s):  
Particle Size ◽  
Phase Transformation ◽  
Powder Metallurgy ◽  
Mechanical Alloying ◽  
Milling Time ◽  
Sintering Temperature ◽  
Silica Sand ◽  
Second Phase ◽  
The Matrix ◽  
The Impact

This study aims to determine the effect of milling time and sintering temperature parameters on the alumina transformation phase in the manufacture of Aluminium Matrix Composites (AMCs) reinforced by 20 % silica sand tailings using powder metallurgy technology. The matrix and fillers use waste to make the composites more efficient, clean the environment, and increase waste utilization. The milling time applied to the Mechanical Alloying (MA) process was 0.5, 6, 24, 48, and 96 hours, with a ball parameter ratio of 15:1 and a rotation of 93 rpm. Furthermore, hot compaction was carried out using a 100 MPa two-way hydraulic compression machine at a temperature of 300 °C for 20 minutes. The temperature variables of the sintering parameter process were 550, 600 to 650 °C, with a holding time of 10 minutes. Characterization of materials carried out included testing particle size, porosity, X-Ray Diffraction (XRD), SEM-Image, and SEM-EDX. The particle measurement of mechanical alloying processed, using Particle Size Analyzer (PSA) instrument and based on XRD data using the Scherrer equation, showed a relatively similar trend, decreasing particle size occurs when milling time was increased 0.5 to 24 hours. However, when the milling time increases to 48 and 96 hours, the particle size tends to increase slightly, due to cold-weld and agglomeration when the Mechanical Alloying is processed. The impact is the occurrence of the matrix and filler particle pairs in the cold-weld state. So, the results of XRD and SEM-EDX characterization showed a second phase transformation to form alumina compounds at a relatively low sintering temperature of 600 °C after the mechanical alloying process was carried out with a milling time on least 24 hours

Effects of Zircon Additive on the Properties of 95-Alumina Ceramic

2007 ◽  
Vol 280-283 ◽  
pp. 1013-1016 ◽  
Author(s):  
Ben Jun Cheng ◽  
Xing Zhong Guo ◽  
Li Li ◽  
Jian Ming Zheng
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Liquid Phase ◽  
Sintering Temperature ◽  
Composite Ceramic ◽  
Alumina Ceramic ◽  
Secondary Crystallization ◽  
Micro Cracks ◽  
Alumina Composite

The mechanism of the effect that zircon additive had on the properties of 95-alumina ceramic was studied and compared with that of zirconia additive. The results show that zircon additive can decrease the sintering temperature of 95-alumina ceramic, the suitable content of zircon additive is 3% and the suitable sintering temperature is1630°C; under these conditions, the 95-alumina composite ceramic can obtain satisfactory sintering and mechanical properties. Compared with zirconia additive, besides the stress-induced-phase-transformation of ZrO2 and micro-cracks, the toughened mechanism of 95-alumina ceramic with zircon additive also includes zirconia secondary crystallization in the liquid phase.

Environmental Phase Stability of Ceramics Composite for Hip Prostheses in Presence of Surface Damage

2007 ◽  
Vol 361-363 ◽  
pp. 783-786 ◽  
Author(s):  
Kiyotaka Yamada ◽  
Giuseppe Pezzotti
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Human Body ◽  
Phase Stability ◽  
Surface Damage ◽  
Material Surface ◽  
Hip Prostheses ◽  
M Phase ◽  
Alumina Matrix Composite

Alumina matrix composite (AMC) has been widely used for artificial hip and knee joints because of its phase stability in human body and its excellent wear resistance. The excellent mechanical properties of strength and fracture toughness of zirconia materials are well known to be closely related to stress-induced transformation from the tetragonal to the monoclinic phase, which is accompanied with 4% volume increase of the zirconia crystal cell. However, it is also to be considered that the material is prone to low temperature aging degradation (LTAD) under hydrothermal environment, like in the human body. This LTAD is influenced by the tetragonal to the monoclinic (t-m) phase transformation. T-m transformation also induces the formation of microcracks at the material surface, and an increase in surface. Microcracking leads to a decrease of mechanical properties, and could explain the failure of implants after some years in vivo [1, 2] .Therefore, it is very important to study how to prevent phase transformation in zirconia components. Transformed monoclinic zirconia percentage can be experimentally measured by Raman spectroscopy and the residual stress distribution, which is related to phase transformation, can be determined by a non-destructive piezo-spectroscopic analysis. In this paper, we attempted to evaluate it from both stress and mechanical properties points of view by confocal Raman and fluorescence spectroscopy.

Step-Sintering of Fe-(1-3)%Mn-0.8%C Steels

2020 ◽  
Vol 405 ◽  
pp. 373-378
Author(s):  
Monika Tenerowicz-Żaba ◽  
Maciej Sułowski
Keyword(s):  
Tensile Strength ◽  
Phase Transformation ◽  
Cooling Rate ◽  
Heating Rate ◽  
Microstructure Evolution ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Tensile Tests ◽  
Transformation Temperatures ◽  
Metallographic Observation

The aim of the study was to examine how the microstructure changes during heating of Fe-Mn-C system (step-sintering). Mixtures of powders containing 1 – 3 % Mn and 0.8 % C were prepared in Turbula TC2 mixer for 30 minutes. Before step-sintering, the dilatometric investigations were carried out, which allowed to obtain phase transformation temperatures of Fe-(1-3)Mn%-0.8%C system. Following dilatometric investigations, 4 steps – temperatures were determined dependently of isothermal sintering temperature. The commonly used industry temperatures – 1120 °C and 1250 °C – were set as target temperatures. For each of them, 4 heat steps were carried out. The procedure of investigations was as follows: samples were heated to the step temperature with heating rate 60 K/min, then isothermally sintered at step temperature for 5 min, and finally cooled to the room temperature with cooling rate ~ 66 K/min. Fe-Mn-C samples were mechanically (tensile) tested. After tensile tests, metallographic observations of the samples were performed. Based on the results obtained, the tensile strength was increasing with the increasing of the step temperature. The metallographic observation showed the microstructure evolution – with increasing the step temperature, decreasing of porosity was observed.

Effects of Postweld Heat Treatment on the Phase Transformation and Mechanical Behavior of NiTi Ultrasonic Spot Welded Joints With Al Interlayer

2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Chunjie Li ◽  
Sansan Ao ◽  
J. P. Oliveira ◽  
Zhi Zeng ◽  
Huijie Cui ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Phase Transformation ◽  
Welded Joints ◽  
Niti Alloy ◽  
Postweld Heat Treatment ◽  
Transformation Temperatures ◽  
Lap Shear ◽  
Lap Shear Test ◽  
Postweld Heat ◽  
Spot Welded

Abstract The influence of postweld heat treatments (PWHTs) on the phase transformation characteristics, microstructural evolution, and mechanical properties of ultrasonic spot welded NiTi alloy with Al interlayer was investigated. At room temperature, the as-welded joints were fully austenitic, while the microstructure of welded joint after PWHT at 450 °C consisted of a mixture of martensite and austenite. The transformation temperatures were found to increase after the PWHT. Transmission electron microscope analysis shows that Al3Ti intermetallic compounds were formed on the Al side of the Al/NiTi interface after the PWHT at 450 °C for 90 min. Furthermore, finely dispersed nanoscale Ni4Ti3 precipitates were observed in the joint. These nanoscale precipitates resulted in an increase in the transformation temperatures and improved the mechanical properties of the PWHT material. During lap shear test, the as-welded samples failed in a brittle manner in the NiTi alloy, while the PWHT samples failed in the Al interlayer and exhibited ductile-like fracture characteristics.

Sign in / Sign up

Export Citation Format

Share Document