scholarly journals Spark Plasma Diffusion Bonding of TiAl/Ti2AlNb with Ti as Interlayer

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3300
Author(s):  
Boxian Zhang ◽  
Chunhuan Chen ◽  
Jianchao He ◽  
Jinbao Hou ◽  
Lu Chai ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Base Metal ◽  
Diffusion Bonding ◽  
Energy Dispersive Spectrometer ◽  
Tensile Tests ◽  
Slow Cooling ◽  
Ti2alnb Alloy ◽  
Heat Treated ◽  
Plasma Diffusion ◽  
Spark Plasma

To solve the problem of poor weldability between TiAl-based and Ti2AlNb-based alloys, spark plasma diffusion bonding was employed to join a TiAl alloy and a Ti2AlNb alloy with a pure Ti foil as interlayer at 950 °C/10 KN/60 min. After welding, slow cooling was carried out at a rate of 5 °C/min, followed by homogenization at 800 °C for 24 h. The microstructural evolution and elemental migration of the joint were analyzed via a scanning electron microscope equipped with an energy dispersive spectrometer, while the mechanical properties of the joint were assessed via microhardness and tensile tests. The results show that the spark plasma diffusion bonding formed a joint of TiAl/Ti/Ti2AlNb without microcracks or microvoids, while also effectively protecting the base metal. Before heat treatment, the maximum hardness value (401 HV) appeared at the Ti2AlNb/Ti interface, while the minimum hardness value (281 HV) occurred in the TiAl base metal. The tensile strength of the heat-treated joint at room temperature was measured to be up to 454 MPa, with a brittle fracture occurring in the interlayer. The tensile strength of the joint at 650 °C was measured to be up to 538 MPa, with intergranular cracks occurring in the TiAl base metal.

Influence of Rotary Friction Welding Parameters on Tensile Strength and Length of TMAZ of Dissimilar Welded Joints from 32G2 and 40KhN Steels

2021 ◽  
Vol 410 ◽  
pp. 299-305
Author(s):  
Artem S. Atamashkin ◽  
Elena Y. Priymak ◽  
Elena A. Kuzmina
Keyword(s):  
Tensile Strength ◽  
Base Metal ◽  
Process Parameters ◽  
Welded Joints ◽  
Friction Welding ◽  
Tensile Tests ◽  
Welding Parameters ◽  
Rotary Friction Welding ◽  
Study Results ◽  
Friction Pressure

In this work, pipe billets with a diameter of 73 mm and a wall thickness of 9 mm from steels 32G2 and 40KhN are friction welded with an aim to optimize the process parameters. The friction pressure, the forging pressure and the length of the fusion varied. After the implementation of various welding modes, tensile tests and metallographic studies were carried out. The optimal welding parameters have been established, which make it possible to obtain tensile strength at the level of the 32G2 base metal. The study results of the microstructure and SEM fractographs after the optimal welding mode are presented.

Properties of Ni-Cu Bulk Alloy Prepared by Spark Plasma Sintering Technique

2012 ◽  
Vol 476-478 ◽  
pp. 949-953
Author(s):  
Li Xin Li
Keyword(s):  
Tensile Strength ◽  
Spark Plasma Sintering ◽  
Tensile Tests ◽  
Arc Plasma ◽  
Bulk Alloy ◽  
Evaporation Method ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Bulk Alloys

Ni-Cu bulk alloys were successfully prepared with spark plasma sintering (SPS) technique from nanopowders obtained by the arc plasma evaporation method. The tensile tests indicated that the tensile strength of Ni-Cu bulk alloy sintered by SPS at 600°C was the highest among the Ni-Cu bulk alloys sintered at different temperature and much higher than that of bulk ingots. Through investigating the fractographs of the bulk alloy, the intrinsic reasons for the tensile strength of the sintered specimens were discussed.

Mechanical properties of heat-treated cellulose nanofiber-reinforced polyvinyl alcohol nanocomposite

2016 ◽  
Vol 51 (14) ◽  
pp. 1971-1977 ◽  
Author(s):  
NH Noor Mohamed ◽  
Hitoshi Takagi ◽  
Antonio N Nakagaito
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Polyvinyl Alcohol ◽  
Tensile Tests ◽  
Cellulose Nanofiber ◽  
Heat Treated ◽  
Scanning Electron ◽  
Polyvinyl Alcohol Films

The mechanical properties of cellulose nanofiber-reinforced polyvinyl alcohol composite were studied. Neat polyvinyl alcohol films, cellulose nanofiber sheets, and their nanocomposites containing cellulose nanofiber weight ratios of 5, 15, 30, 40, 45, 50 and 80 wt% were fabricated. Heat treatment by hot pressing at 180℃ was conducted on the specimens to study its effect to the mechanical properties and the results were compared with the non heat-treated specimens. Morphology of the composites was studied by scanning electron microscopy and the mechanical properties were evaluated by means of tensile tests. The results showed that increase of cellulose nanofiber content from 5 wt% to 80 wt% has increased the tensile strength of the composites up to 180 MPa, with cellulose nanofiber content higher than 40 wt% yielding higher tensile strength. The heat-treated specimens exhibited higher tensile strength compared to those of untreated specimens.

scholarly journals Advanced Mechanical Strength in Post Heat Treated SLM 2507 at Room and High Temperature Promoted by Hard/Ductile Sigma Precipitates

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 199 ◽  
Author(s):  
Kamran Saeidi ◽  
Sajid Alvi ◽  
Frantisek Lofaj ◽  
Valeri Ivanov Petkov ◽  
Farid Akhtar
Keyword(s):  
Tensile Strength ◽  
Stainless Steel ◽  
Mechanical Strength ◽  
Sigma Phase ◽  
Heat Treating ◽  
Tribological Behaviour ◽  
Wear Properties ◽  
Slow Cooling ◽  
Heat Treated ◽  
Duplex Steel

Duplex stainless steel, 71 wt.% austenite, 13 wt.% ferrite and 16 wt.% sigma, was made upon heat treating of fully ferritic as-built selective laser melted (SLM) 2507 stainless steel at 1200 °C. Formation of sigma phase in the heat treated SLM 2507 was investigated using optical microscopy and scanning electron microscopy (SEM). The heat treated SLM 2507 demonstrated a yield strength of 686 MPa, ultimate tensile strength of 920 MPa and an elongation of 1.8% at room temperature with a brittle fracture morphology. Precipitation of sigma phase during heat treatment and slow cooling improved the mechanical and wear properties at high temperatures (1200 °C and 800 °C, respectively). The tensile strength and elongation of the heat treated SLM 2507 was measured 400 MPa and 20% as compared to casted duplex steel with 19 MPa and 30% elongation at 1200 °C. The 20 times higher mechanical strength as compared to casted duplex steel was attributed to sigma precipitates. Tribological behaviour of heat treated duplex SLM 2507 containing sigma at 800 °C showed very low wear rate of 4.5 × 10−5 mm3/mN compared to casted duplex steel with 1.6 × 10−4 mm3/mN.

Study on Mechanical Properties at High Temperatures and Microstructure of Mg-12Gd-3Y-0.5Zr Magnesium Alloy

2014 ◽  
Vol 997 ◽  
pp. 618-623 ◽  
Author(s):  
Tian Dong Cao ◽  
Xiao Ming Yang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
High Temperatures ◽  
Tensile Tests ◽  
Strengthening Mechanism ◽  
Heat Treated ◽  
Different Temperatures ◽  
Solution Strengthening ◽  
Tension Compression Asymmetry

In this paper, tensile tests were carried out on the as-rolled and heat-treated Mg-12Gd-3Y-0.5Zr magnesium alloy at different temperatures. Tendency of tensile strength vs temperature was investigated and strengthening mechanism was discussed. It shows that both as-rolled and heat-treated Mg-12Gd-3Y-0.5Zr magnesium alloy have good mechanical properties at high temperatures. The reason why they have poor tension-compression asymmetry was discussed by their texture analysis. It is indicated that solution strengthening and precipitation strengthening were main strengthening mechanisam, and RE additons improve their thermal stability which lead to their high tensile strength at high temperatures.

Effects of particulate reinforcements on the hardness, impact and tensile strengths of AA 6061-T6 friction stir weldments

2021 ◽  
pp. 146442072199554
Author(s):  
TE Abioye ◽  
H Zuhailawati ◽  
AS Anasyida ◽  
SP Ayodeji ◽  
PK Oke
Keyword(s):  
Tensile Strength ◽  
Impact Strength ◽  
Base Metal ◽  
Welded Joint ◽  
High Hardness ◽  
Friction Stir ◽  
Heat Treated ◽  
Impact Energies ◽  
The Impact ◽  
Metal Hardness

Due to loss of structural strengthening at temperatures beyond 250°C, heat-treated aluminium alloys (e.g. AA 6061-T6) weldments are usually characterized with poor mechanical properties including hardness, tensile and impact strengths. In this work, friction stir weldments of AA 6061-T6 reinforced with the additions of SiC, B4C and Al2O3 particles at the joints were produced and investigated for improved hardness, tensile strength and impact strength over the unreinforced weldment. The results showed that the entire reinforced welded joint exhibited improved hardness because of the enhanced metal matrix grain refinement and inherent high hardness of the reinforcement particles. B4C particle addition produced hardest joint of about 81% of the base metal hardness (∼114 HV0.3). The impact energies of the SiC (16.9 J), B4C (16.5) and Al2O3 (12.2 J) reinforced weldments are closer to that of the base metal (18.6 J) compared with the unreinforced weldment (9.6 J). The reinforced weldments showed no significant improvement over the tensile strength of the unreinforced weldment. B4C and SiC reinforcements produced the highest improvements in the hardness (at the joint) and impact strength of the AA 6061-T6 friction stir weldments, respectively.

Creep and Creep Rupture of FSW Joints of 5052 Aluminium Alloy Plates

2006 ◽  
Vol 519-521 ◽  
pp. 1175-1180
Author(s):  
Makoto Sugamata ◽  
Masayuki Genei ◽  
Masahiro Kubota ◽  
Junichi Kaneko
Keyword(s):  
Tensile Strength ◽  
Base Metal ◽  
Minimum Creep Rate ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Creep Rupture ◽  
Sectional Area ◽  
Cross Sectional ◽  
Friction Stir ◽  
Round Bar

Creep and creep rupture tests were carried out for friction-stir-welded (FSW) joints of 5052 aluminum alloy plates at temperatures between 573 and 723 K. The results were compared with those of the base metal. 5052-O plates of 20 mm in thickness were joined by FSW and round bar creep specimens were machined out of the welded plates. Tensile tests were also conducted at RT, 623 and 723K for both FSW joints and base metal. The tensile strength of the joints was almost the same as that of the base metal at room and elevated temperatures. However, the FSW joints showed appreciably higher minimum creep rate and shorter rupture time than the base metal at all the tested temperatures and initial creep stresses. Creep rupture of the joints always occurred within the plastically stirred zone with lower contraction of cross-sectional area. Thus, FSW joints of 5052 alloy plates showed lower creep strength than the base metal.

scholarly journals Tensile and Hardness Tests on Steel Specimen

2020 ◽  
Vol 9 (4) ◽  
pp. 1607-1610
Keyword(s):  
Tensile Strength ◽  
Mild Steel ◽  
Steel Specimen ◽  
Tensile Tests ◽  
The Other ◽  
Material Strength ◽  
Maximum Hardness ◽  
Slow Cooling ◽  
Hardness Tests ◽  
Relationship Of

Steel specimens were subjected to both tensile tests and hardness tests. The tests were carried out Mild steel .The specimens were tested under various conditions. The maximum hardness was for the specimen quenched with water, however the tensile strength of that particular specimen was the minimum. While the tensile strength was highest for slow cooling and furnace cooling .However the hardness for slow cooling was the least. While furnace cooling was comparatively higher. The other specimens had varied tensile strength and hardness and it was not possible to map a relationship of the two. The motivation for this work has been that the students involved have recently been exposed to material strength and its variation with temperature

scholarly journals Influence of Heat Treatment on Microstructure and Properties of NiTi46 Alloy Consolidated by Spark Plasma Sintering

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4075 ◽  
Author(s):  
Pavel Salvetr ◽  
Jaromír Dlouhý ◽  
Andrea Školáková ◽  
Filip Průša ◽  
Pavel Novák ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Shape Memory ◽  
Spark Plasma Sintering ◽  
Scanning Calorimetry ◽  
Slow Cooling ◽  
Plasma Sintering ◽  
High Temperature Synthesis ◽  
Heat Treated ◽  
Spark Plasma

Ni-Ti alloys are considered to be very important shape memory alloys with a wide application area including, e.g., biomaterials, actuators, couplings, and components in automotive, aerospace, and robotics industries. In this study, the NiTi46 (wt.%) alloy was prepared by a combination of self-propagating high-temperature synthesis, milling, and spark plasma sintering consolidation at three various temperatures. The compacted samples were subsequently heat-treated at temperatures between 400 °C and 900 °C with the following quenching in water or slow cooling in a closed furnace. The influence of the consolidation temperature and regime of heat treatment on the microstructure, mechanical properties, and temperatures of phase transformation was evaluated. The results demonstrate the brittle behaviour of the samples directly after spark plasma sintering at all temperatures by the compressive test and no transformation temperatures at differential scanning calorimetry curves. The biggest improvement of mechanical properties, which was mainly a ductility enhancement, was achieved by heat treatment at 700 °C. Slow cooling has to be recommended in order to obtain the shape memory properties.

scholarly journals Microstructure and Mechanical Properties of the Ni/Ti/Nb Multilayer Composite Manufactured by Accumulative Pack-roll Bonding

2020 ◽  
Author(s):  
Nan Ye ◽  
Xue-ping Ren
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Tensile Strength ◽  
Energy Dispersive Spectrometer ◽  
Tensile Tests ◽  
Multilayer Composite ◽  
Micro Hardness ◽  
Roll Bonding ◽  
Transmission Electron ◽  
Equiaxed Grains

In this work, the Ni/Ti/Nb multilayer composite was successfully manufactured by accumulative pack-roll bonding. The microstructure evolution and mechanical properties of the composite during the accumulative roll bonding (ARB) process were investigated by scanning electron microscopy(SEM), energy dispersive spectrometer(EDS), transmission electron microscopy (TEM), micro-hardness and tensile tests. The results showed that after 5 passes of the ARB process, the deformations of layers were relatively uniform, and no large number of interlayer fractures occurred. The microstructures of Ni and Ti were both equiaxed grains with a grain size of 200 nm and 150 nm, respectively, and finer equiaxed grains of the Ni layer were observed at the interface. The laminar structure of Nb layer was observed. The tensile strength and micro-hardness increased significantly as the number of ARB increased. After 5 passes of the ARB process, the tensile strength of the composite reached 792.3 MPa, and the micro-hardness of Ni, Ti, and Nb were increased to 270.2, 307.4, and 243.4 HV, respectively.

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