scholarly journals Mechanical Properties and Microstructure of DMLS Ti6Al4V Alloy Dedicated to Biomedical Applications

Materials ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 176 ◽  
Author(s):  
Żaneta Anna Mierzejewska ◽  
Radovan Hudák ◽  
Jarosław Sidun
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Boundary Effect ◽  
High Porosity ◽  
Elongation At Break ◽  
Horizontal Orientation ◽  
Before And After ◽  
Columnar Grains ◽  
Powder Particles ◽  
Selection Of

The aim of this work was to investigate the microstructure and mechanical properties of samples produced by direct metal laser sintering (DMLS) with varied laser beam speed before and after heat treatment. Optical analysis of as-built samples revealed microstructure built of martensite needles and columnar grains, growing epitaxially towards the built direction. External and internal pores, un-melted or semi-melted powder particles and inclusions in the examined samples were also observed. The strength and Young’s modulus of the DMLS samples before heat treatment was higher than for cast and forged samples; however, the elongation at break for vertical and horizontal orientation was lower than required for biomedical implants. After heat treatment, the hardness of the samples decreased, which is associated with the disappearance of boundary effect and martensite decomposition to lamellar mixture of α and β, and the anisotropic behaviour of the material also disappears. Ultimate tensile strength (UTS) and yield strength(YS) also decreased, while elongation increased. Tensile properties were sensitive to the build orientation, which indicates that DMLS generates anisotropy of material as a result of layered production and elongated β prior grains. It was noticed that inappropriate selection of parameters did not allow properties corresponding to the standards to be obtained due to the high porosity and defects of the microstructure caused by insufficient energy density.

Microstructure and Mechanical Properties of Ti-6Al-4V Manufactured by SLM

2015 ◽  
Vol 651-653 ◽  
pp. 677-682 ◽  
Author(s):  
Anatoliy Popovich ◽  
Vadim Sufiiarov ◽  
Evgenii Borisov ◽  
Igor Polozov
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Phase Composition ◽  
Mechanical Behavior ◽  
Ductile Fracture ◽  
Elevated Temperatures ◽  
Initial Material ◽  
Laser Melting ◽  
Microstructure And Mechanical Properties ◽  
Before And After

The article presents results of a study of phase composition and microstructure of initial material and samples obtained by selective laser melting of titanium-based alloy, as well as samples after heat treatment. The effect of heat treatment on microstructure and mechanical properties of specimens was shown. It was studied mechanical behavior of manufactured specimens before and after heat treatment at room and elevated temperatures as well. The heat treatment allows obtaining sufficient mechanical properties of material at room and elevated temperatures such as increase in ductility of material. The fractography of samples showed that they feature ductile fracture with brittle elements.

scholarly journals Effect of Mo, V and Zr on the microstructure and mechanical properties of Ti2AlNb alloys

2020 ◽  
Vol 321 ◽  
pp. 08003
Author(s):  
Yujun Du ◽  
Xianghong Liu ◽  
Jinshan Li ◽  
Wenzhong Luo ◽  
Yongsheng He ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Melting Process ◽  
Phase Region ◽  
Arc Furnace ◽  
Micro Hardness ◽  
Β Phase ◽  
Before And After ◽  
B2 Phase ◽  
O Phase

Small button ingots of Ti2AlNb alloys with different contents of Mo, V and Zr were melted by vacuum non-consumable arc furnace. Due to the rapid cooling rate during melting process, only β grains without precipitation were observed in most of the button ingots and no regular phenomenon was found. However, when the samples were heated to β phase region and then furnace cooled to room temperate, different morphologies and quantities of primary α phase and second O phase formed from the β grains of different samples. It is suggested that the morphology of α phase was changed from lamellar to quadrilateral with increasing V and the lath O increased with increasing Zr. Besides, the residual β/B2 phase increased with increasing Mo and V. The EDS results showed that Al and Zr were enriched in α phase whereas Nb, Mo and V were enriched in β/B2 phase. The micro-hardness of these samples before and after heat treatment was detected and the micro-hardness increased with increasing Zr and decreasing Mo and V.

scholarly journals Effect of heat treatment on the tribological properties of Nickel-Boron electroless coating

2018 ◽  
Vol 27 (47) ◽  
pp. 101
Author(s):  
Sandra Arias ◽  
Maryory Gómez ◽  
Esteban Correa ◽  
Félix Echeverría-Echeverría ◽  
Juan Guillermo Castaño
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Wear Resistance ◽  
Carbon Steel ◽  
Tribological Properties ◽  
Tribological Performance ◽  
Dry Sliding ◽  
Electroless Coating ◽  
Before And After ◽  
Properties Of Materials

Nickel-Boron autocatalytic coatings are widely used in several industries to improve mechanical properties of materials such as hardness and wear resistance. Tribological properties were evaluated in Ni-B autocatalytic coatings deposited on AISI/SAE 1018 carbon steel before and after a heat treatment at 450 °C for one hour. Tribological tests were carried out by dry sliding, using a load of 5 N and a sliding speed of 0.012 m/s, in a homemade ball-on-disk tribometer, which followed ASTM G99 standard. According to the tribological evaluation, the heat treatments applied to Ni-B coatings improved their tribological performance. This research corroborates that by applying an adequate heat treatment, hardness and wear resistance of Ni-B coatings can be improved significantly.

Microstructure and Mechanical Properties of TiB2/ Al-Si Composites Fabricated by TIG Wire and Arc Additive Manufacturing

2019 ◽  
Vol 944 ◽  
pp. 64-72
Author(s):  
Qing Feng Yang ◽  
Cun Juan Xia ◽  
Ya Qi Deng
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Additive Manufacturing ◽  
Yield Strength ◽  
Filler Wire ◽  
T6 Heat Treatment ◽  
Microstructure And Mechanical Properties ◽  
Before And After

Bulky sample was made by using TIG wire and arc additive manufacturing (WAAM) technology, in which Ф1.6 mm filler wire of in-situ TiB2/Al-Si composites was selected as deposition metal, following by T6 heat treatment. The microstructure and mechanical properties of the bulky sample before and after heat treatment were analyzed. Experimental results showed that the texture of the original samples parallel to the weld direction and perpendicular to the weld direction was similar consisting of columnar dendrites and equiaxed crystals. After T6 heat treatment, the hardness of the sample was increased to 115.85 HV from 62.83 HV, the yield strength of the sample was 273.33 MPa, the average tensile strength was 347.33 MPa, and the average elongation after fracture was 7.96%. Although pore defects existed in the fracture, yet the fracture of the sample was ductile fracture.

The Microstructure and Compression Behavior of Multi-Step Forging Ti-45Al-8Nb Alloy after Annealing at 1100 °C

2013 ◽  
Vol 747-748 ◽  
pp. 111-114
Author(s):  
Lin Song ◽  
Xiang Jun Xu ◽  
Jun Pin Lin ◽  
Lai Qi Zhang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Annealing Treatment ◽  
Air Cooling ◽  
Test Machine ◽  
Compressive Properties ◽  
Compression Behavior ◽  
Microstructure Change ◽  
Heat Treated ◽  
Before And After

Effects of annealing treatment on microstructure and the compressive properties of hot-worked Ti-45Al-8Nb-(W, B, Y) alloy were investigated. Microstructure of the extrusion plus multi-step forging pancake before and after heat treatment was analyzed by SEM and TEM, respectively. The annealing was conducted by holding samples at 1100°C for 2hrs, and followed by air cooling and furnace cooling. The mechanical properties were measured by Instron test machine. The microstructure evolution during compressive deformation was analyzed by TEM. The results showed that after the annealing the microstructure change could not be observed under SEM but can be observed under TEM. Many dislocation clusters were removed by heat treatment. The heat treated samples had similar compression behaviors with the pancake. TEM investigation showed that the numerous twin intersections occured in γ matrix during compression. The twin spaces tended to decrease as the deformation and the intersection increasing.

Study on Mechanical Properties Aging of Spray Pure Polyurea for Hydraulic Concrete Protection

2011 ◽  
Vol 374-377 ◽  
pp. 1325-1329 ◽  
Author(s):  
Wei Bo Huang ◽  
Jia Yu Xiang ◽  
Ping Lv ◽  
Xin Mao Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Development Trend ◽  
Elongation At Break ◽  
Tear Strength ◽  
Hydraulic Concrete ◽  
Before And After ◽  
Ultraviolet Ray ◽  
Resistance Performance

Researches of spray pure polyurea technology for hydraulic concrete protection in water conservancy facilities to ensure long term security operation has a great significance. With an emphasis upon mechanical properties and surface morphology of spray pure polyurea coatings comparing before and after aging by means of the artificial accelerated xenon arc lamp(AAXAL) and scanning electron microscope(SEM) in this paper. Besides, the dry-wet circulation resistance performance of coatings wre analyzed through experiment. It is shown that tensile strength, elongation at break and tear strength of coatings increased by 0.2%, 0.5% and 1.7% respectively after AAXAL aging 720h. By contrast, after aging 3000h the results were 22.6%, 3.8% and 17.4% respectively, the tendency of increasing at first and then reducing can be obtained. The mechanical properties reduced slightly for adding defects of coating surface after aging, however, the resistance performance of ultraviolet ray was excellent. The similar development trend of mechanical properties were gained from dry-wet circulation experiment. After aging 200 cycles, the tensile strength and tear strength descended by 4.1% and 1.7% severally but the elongation at break ascended by 5.0%. In a word, it is suggested that the aging of coatings were negligible in dry-wet circulation in short term.

Studying of Microstructure and Properties of Selective Laser Melted Titanium-Based Alloy

2015 ◽  
Vol 1120-1121 ◽  
pp. 1269-1275
Author(s):  
Anatoly A. Popovich ◽  
Vadim Sh. Sufiiarov ◽  
Igor A. Polozov ◽  
Evgenii V. Borisov ◽  
Maxim Y. Maximov
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Phase Composition ◽  
Mechanical Behavior ◽  
Selective Laser Melting ◽  
Powder Material ◽  
Elevated Temperatures ◽  
Initial Powder ◽  
Laser Melting ◽  
Before And After

The article presents the results of selective laser melting of Ti-6Al-4V alloy. It was studied phase composition and microstructure of the initial powder material, the specimens manufactured by Selective Laser Melting and also the specimens after heat treatment. The effect of heat treatment on microstructure and mechanical properties of the specimens was shown. It was studied the mechanical behavior of the manufactured specimens before and after heat treatment at room and elevated temperatures as well. After heat treatment tests showed that the specimens have decent mechanical properties both at room and elevated temperatures.

scholarly journals Influence of electron irradiation on mechanical properties of epoxy polymers

2020 ◽  
Vol 99 (3) ◽  
pp. 80-85
Author(s):  
Yu.A. Udovytska ◽  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Epoxy Resin ◽  
Electron Irradiation ◽  
Thermal Destruction ◽  
Optimal Choice ◽  
Additional Heat ◽  
Epoxy Polymers ◽  
Absorbed Doses ◽  
Before And After

The effect of different absorbed doses of electron irradiation with the energy of 12 MeV and heat treatment on the mechanical properties of ED-20 epoxy-dianic resin with hardener PEPA (11, 12 and 13 parts by weight per 100 parts by weight of epoxy resin) was investigated. Heat treatment of irradiated epoxy resin samples was performed in two modes: before or after electron irradiation. It is shown that the optimal choice of the content of hardener PEPA and using electron irradiation with the energy of 12 MeV in the integrated combination with heat treatment allow significantly improve the mechanical properties of epoxy-dianic resin. It was established that for the content of the hardener 12 parts by weight and absorbed doses of 10–20 kGy, the boundary of strength increases in 3 times, and additional heat treatment both before and after irradiation reduces this figure through the thermal destruction. Only for the content of hardener 11 and 13 parts by weight and these absorbed doses heat treatment of irradiated samples of epoxy resin leads to an increase in the boundary of strength. In doing so, the hardness increases regardless of the content of hardener for the absorbed doses greater than 50 kGy.

scholarly journals TO STUDY MECHANICAL PROPERTIES OF SPRING LIKE SPECIMEN BEFORE AND AFTER DIFFERENT HEAT TREATMENT OPERATIONS

2020 ◽  
Vol 6 (6) ◽  
pp. 1-8
Author(s):  
Amit Kumar
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Treatment Temperature ◽  
Muffle Furnace ◽  
Soaking Time ◽  
Standard Data ◽  
Treatment Processes ◽  
Specimen Material ◽  
Material Specimen ◽  
Before And After

In this work we have analyzed the effect heat treatment on properties of spring shape steel specimens under various heat treatment processes. Specimen was subjected to heat treatment in electric muffle furnace. Heat treatment temperature, soaking time and cooling rate were selected as per phase diagram of specimen material. Specimen was tested for mechanical properties before and after heat treatment. Two processes annealing and normalizing compared with respect to their effect on properties of spring shape specimens in reference with standard data for steel used.

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