scholarly journals A study of dental soldering. (Part IX). Tensile strength of nickel-chromium base metal presoldered joints, soldered by focused energy of infra-red.

1988 ◽  
Vol 32 (4) ◽  
pp. 814-820 ◽  
Author(s):  
Yoshiyuki Hagiwara ◽  
Hiromi Osawa ◽  
Masataka Shibuya ◽  
Masayuki Tomomatsu ◽  
Shinya Hanamura ◽  
...  
2021 ◽  
Vol 410 ◽  
pp. 299-305
Author(s):  
Artem S. Atamashkin ◽  
Elena Y. Priymak ◽  
Elena A. Kuzmina

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.


2021 ◽  
Vol 2079 (1) ◽  
pp. 012022
Author(s):  
Yongchao Jian ◽  
Yan Shi

Abstract Because of the uneven distribution of reinforcement particles in the molten pool during laser welding of SiCp/6061Al composites with powder, the effect of pulse frequency on the homogenization was studied in this paper. The pulse frequency of welding is changed and the macro morphology of the weld is studied by metallographic microscope. The particle uniformity of reinforcing phase and the porosity of molten pool at different frequencies were compared. The tensile strength of welded joints at different frequencies was tested by universal tensile machine. Finally, when the pulse frequency is 160Hz, the particle distribution of reinforcing phase is the most uniform and the tensile strength is the largest. The tensile strength reaches 267.06MPa, reaching 69.1% of the base metal. When the pulse frequency is 320Hz, the porosity of the weld is the lowest, reaching 1.75%.


2019 ◽  
Vol 22 (2) ◽  
pp. 143-150
Author(s):  
Hussain J. M. Al-Alkawi ◽  
Abduljabbar Owaid Hanfesh ◽  
Saja Mohammed Noori Mohammed Rauof

This research is devoted to study the influence of different weight percent concerning to the additions of Ti and Cu on mechanical and tribological properties of AA6061. The composite materials consist of different weight percentage of Ti (0.2, 0.4, and 0.6) wt% and constant weight percentage of Cu (0.2) wt% which were fabricated by liquid metallurgy route technique. Microstructural characterization and phases have been examined by using SEM (scanning electron microscopic).SEM examination showed uniform distribution of nano Ti and Cu in AA6061. The consequences of mechanical tests demonstrated clear enhancement in mechanical properties, such as ultimate tensile strength, yield strength, young modulus, ductility% and hardness at additive percentage of 0.4% Ti+0.2%Cu nano particles incorporated into molten AA6061. Percentage of enhancement ultimate tensile strength is about 73.3%, yield strength about 82.7%, young modulus is about 21.2%, the  Vickers hardness about 42.6% and the decreasing in ductility was about 25.2% compared with the metal matrix (AA6061). The wear rate test was performed by using pin on disc rig for both hybrid nano composite and base metal (AA6061) under various loads (10,15and 20) N with sliding speed (1.282) m/sec at a (10) min’s time. The results showed a decrease in wear rate at 0.4%Ti+0.2%Cu compared with the base metal (AA6061). Improvement percentage of wear rate is about 105% at 20 N load.


2014 ◽  
Vol 22 (1) ◽  
pp. 93-98
Author(s):  
Pavol Švec ◽  
Viliam Hrnčiar ◽  
Alexander Schrek

AbstractThe effects of beam power and welding speed on microstructure, microhardnes and tensile strength of HCT600X laser welded steel sheets were evaluated. The welding parameters influenced both the width and the microstructure of the fusion zone and heat affected zone. The welding process has no effect on tensile strength of joints which achieved the strength of base metal and all joints fractured in the base metal.


Author(s):  
Masaaki Kimura ◽  
Akira Yoneda ◽  
Masahiro Kusaka ◽  
Koichi Kaizu ◽  
Kazuhiro Hayashida ◽  
...  

Abstract To obtain dissimilar joint for easily making multi-material structures, the characteristics of friction welded joint between ductile cast iron (FCD400) and 5052 Al alloy (A5052) was investigated. The relatively high tensile strength of joint was obtained when that was made with a friction speed of 27.5 s−1, a friction pressure of 20 MPa, a friction time of 1.5 s, and a forge pressure of 270 MPa, respectively. However, this joint had approximately 77% in the tensile strength of the A5052 base metal and that was fractured at the weld interface. Although the weld interface had no intermetallic compound layer, the fractured surface at the A5052 side had some graphite particles that were supplied from the FCD400 side. To improve the joint strength, the graphite particles were reduced from the weld faying surface at the FCD400 side by decarburization treatment. The joint had approximately 96% in the tensile strength of the A5052 base metal and that was fractured between the A5052 side and the weld interface. The joint with high tensile strength as well as the possibility improving the fractured point of that were obtained when those were made with opportune friction welding condition and no graphite particles at the weld faying surface of the FCD400 side.


Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3300
Author(s):  
Boxian Zhang ◽  
Chunhuan Chen ◽  
Jianchao He ◽  
Jinbao Hou ◽  
Lu Chai ◽  
...  

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.


2019 ◽  
Vol 269 ◽  
pp. 02006
Author(s):  
Li Fu ◽  
Fenjun Liu

Al-Mg-Si (6061-T6) alloy with 0.8 mm thick plate was welded successfully by use of high speed friction stir welding (FSW) technology. The microstructural characteristics and mechanical property of the butt joints prepared by high speed FSW were analyzed in detail, the influence of welding parameters, fixture condition and after welding heat treatment were also explored. The results shown that sound surface topography and defect-free bonding interface were observed in the nugget zone (NZ). The microhardness of the as-welded joint was lower than that of the base metal because of the welding heat effect. Compared with the conventional speed FSW, the number of β-Mg2Si, Al2CuMg and Al8Fe2Si precipitated phases existed in the high speed FSWed NZ increased, which made the microhardness in the NZ improved significantly. The rod-shaped precipitates (Mg2Si) have the greatest influence on the microhardness distributions. The maximum tensile strength of 301.8 MPa, which was 85.8% of the base metal, was obtained at high rotation speed of 8000 rpm and fast welding speed of 1500 mm/min. The tensile strength of the ultra-high speed FSWed butt joints were improved significantly by post-weld artificial aging, with a maximum joint efficiency of 90.4%.


1984 ◽  
Vol 52 (5) ◽  
pp. 666-672 ◽  
Author(s):  
Allan G. Marshall ◽  
Richard J. Goodkind

2011 ◽  
Vol 255-260 ◽  
pp. 132-136
Author(s):  
Hong Yu Qi ◽  
Jian Xie ◽  
Dong Pan ◽  
Shao Lin Li ◽  
Xiao Guang Yang

Forged Ti-6Al-4V welded structure by electronic beam welding (EBW) as integrally bladed disk (blisk) structure in advanced aero-engine has been widely applied. It is necessary to analyze microstructure and mechanical properties of Ti-6Al-4V welded joints by EBW for failure analysis and structure design of blisk. Firstly the microstructure and mechanical properties of forged Ti-6Al-4V welded joints was focused on. Grains in the weld zone become coarse and large gradient organization structure appears in the heat affected zone (HAZ), which presents significant local heterogeneity. Microhardness of the weld zone is about 20% higher than that of the base metal. The size of different region of the welded joints was estimated. Then static tensile test of three different specimens were carried on. Experiment results show that the tensile and yield strength of welded joints are not less than that of the base metal. Finally the empirical relationship between strength and hardness of Ti-6Al-4V alloy is established. Tensile strength of the weld zone and the base metal were estimated. Compared to experiment data, the deviation is 3.56%, 0.097% respectively.


2014 ◽  
Vol 40 (3) ◽  
pp. 239-249 ◽  
Author(s):  
Jaini Jaini Lalithamma ◽  
Sreekanth Anantha Mallan ◽  
Pazhani Appan Murukan ◽  
Rita Zarina

The study compared the marginal accuracy of premade and cast abutments. Premade titanium, stainless steel, and gold abutments formed the control groups. Plastic abutments were cast in nickel-chromium, cobalt-chromium and grade IV titanium. The abutment/implant interface was analyzed. Analysis of variance and Duncan's multiple range test revealed no significant difference in mean marginal microgap between premade gold and titanium abutments and between premade stainless steel and cast titanium abutments. Statistically significant differences (P < .001) were found among all other groups.


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