Effect of defocusing amount on morphology and microstructure of 8-mm-thick Ti-6Al-4 V laser deep penetration welded joint

The microstructure, the regular and mechanism of various parameters on formation of weld bead of Mg alloy AMCa403 using a laser welding were investigated. The results show that sound welds without major defects can be produced. Two welding modes of deep penetration welding, heat conduction welding were found, and heat input was found to be the main factor for welding mode and shape. The microstructure of weld metal is significantly finer than the base metal. At the same power, with the increase of welding speed, the microstructure of weld metal is much finer.

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Microstructure and defect of titanium alloy electron beam deep penetration welded joint

Transactions of Nonferrous Metals Society of China ◽

10.1016/s1003-6326(11)61510-0 ◽

2012 ◽

Vol 22 (11) ◽

pp. 2633-2637 ◽

Cited By ~ 10

Author(s):

Bing-gang ZHANG ◽

Ming-xiao SHI ◽

Guo-qing CHEN ◽

Ji-cai FENG

Keyword(s):

Titanium Alloy ◽

Electron Beam ◽

Welded Joint ◽

Deep Penetration

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Investigation into plastic damage behavior of the CO2 laser deep penetration welded joint for Ti–6Al–4V alloy

Engineering Fracture Mechanics ◽

10.1016/j.engfracmech.2011.08.011 ◽

2012 ◽

Vol 83 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Zhang Jianxun ◽

Song Xu ◽

Zheng Li

Keyword(s):

Co2 Laser ◽

Welded Joint ◽

Deep Penetration ◽

Damage Behavior ◽

Plastic Damage

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Welded joint

AccessScience ◽

10.1036/1097-8542.743700 ◽

2015 ◽

Keyword(s):

Welded Joint

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Kapitalistische Krisen mit und ohne systemischer Herausforderung.

PROKLA Zeitschrift für kritische Sozialwissenschaft ◽

10.32387/prokla.v46i185.130 ◽

2016 ◽

Vol 46 (185) ◽

pp. 543-560 ◽

Cited By ~ 1

Author(s):

Ingo Schmidt

Keyword(s):

World Market ◽

Second World War ◽

Deep Penetration ◽

World War ◽

Major Overhaul ◽

Domestic Markets ◽

Global Restructuring ◽

Social Divisions ◽

Class Power ◽

Second World

This article draws on Marxist theories of crises, imperialism, and class formation to identify commonalities and differences between the stagnation of the 1930s and today. Its key argument is that the anti-systemic movements that existed in the 1930s and gained ground after the Second World War pushed capitalists to turn from imperialist expansion and rivalry to the deep penetration of domestic markets. By doing so they unleashed strong economic growth that allowed for social compromise without hurting profits. Yet, once labour and other social movements threatened to shift the balance of class power into their favor, capitalist counter-reform began. In its course, global restructuring, and notably the integration of Russia and China into the world market, created space for accumulation. The cause for the current stagnation is that this space has been used up. In the absence of systemic challenges capitalists have little reason to seek a major overhaul of their accumulation strategies that could help to overcome stagnation. Instead they prop up profits at the expense of the subaltern classes even if this prolongs stagnation and leads to sharper social divisions.

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Calculation And Experimental Substantiation Of Optimal Design Of The Welded Joint Of Plates On Соver Plates

Promyshlennoe i Grazhdanskoe Stroitel stvo ◽

10.33622/0869-7019.2020.03.17-24 ◽

2020 ◽

pp. 17-24

Keyword(s):

Welded Joint ◽

Experimental Studies ◽

Engineering Calculation ◽

Tensile Tests ◽

Physical Nonlinearity ◽

Steel Plates ◽

Optimal Parameters ◽

Actual Problem ◽

Numerical Research ◽

Cover Plates

The article is devoted to the actual problem of assigning optimal parameters for connecting steel plates on cover plates with angular welds that are widely used in construction practice. The article presents the results of a comprehensive study of operation of a welded assembly of the plates connection on cover plates. An algorithm is proposed for determining the optimal parameters of a welded joint with fillet welds on the cover plates, which makes it possible to obtain a strength balanced connection. The results of full-scale tensile tests of models were presented. These results confirmed the correctness of the assumed design assumptions, and made it possible to obtain a form of destruction, not characteristic and not described in the normative literature, expressed by cutting the main elements along the length of the overlap in the joint. The possibility of such a form of destruction was confirmed by the results of numerical research in a nonlinear formulation. The optimal parameters of the nodal welded joint determined by engineering calculation are confirmed by experimental studies, as well as by the results of numerical experiments on models of calculation schemes, taking into account the physical nonlinearity of the material operation. The obtained dependence for determining the bearing capacity of the joint by the cut-off mechanism and the expression for limiting the overlap length of the cover plates will make it possible to predict the nature of the fracture and design equally strong joints.

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An appraisal of characteristic mechanical properties and microstructure of friction stir welding for Aluminium 6061 alloy – Silicon Carbide (SiCp) metal matrix composite

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES ◽

10.15282/jmes.13.4.2019.07.0463 ◽

2019 ◽

Vol 13 (4) ◽

pp. 5804-5817

Author(s):

Ibrahim Sabry

Keyword(s):

Tensile Strength ◽

Ultimate Tensile Strength ◽

Metal Matrix Composite ◽

Matrix Composite ◽

Metal Matrix ◽

Welded Joint ◽

Rotation Speed ◽

Fusion Welding ◽

Friction Stir ◽

Al 6061

It is expected that the demand for Metal Matrix Composite (MMCs) will increase in these applications in the aerospace and automotive industries sectors, strengthened AMC has different advantages over monolithic aluminium alloy as it has characteristics between matrix metal and reinforcement particles. However, adequate joining technique, which is important for structural materials, has not been established for (MMCs) yet. Conventional fusion welding is difficult because of the irregular redistribution or reinforcement particles. Also, the reaction between reinforcement particles and aluminium matrix as weld defects such as porosity in the fusion zone make fusion welding more difficult. The aim of this work was to show friction stir welding (FSW) feasibility for entering Al 6061/5 to Al 6061/18 wt. % SiCp composites has been produced by using stir casting technique. SiCp is added as reinforcement in to Aluminium alloy (Al 6061) for preparing metal matrix composite. This method is less expensive and very effective. Different rotational speeds,1000 and 1800 rpm and traverse speed 10 mm \ min was examined. Specimen composite plates having thick 10 mm were FS welded successfully. A high-speed steel (HSS) cylindrical instrument with conical pin form was used for FSW. The outcome revealed that the ultimate tensile strength of the welded joint (Al 6061/18 wt. %) was 195 MPa at rotation speed 1800 rpm, the outcome revealed that the ultimate tensile strength of the welded joint (Al 6061/18 wt.%) was 165 MPa at rotation speed 1000 rpm, that was very near to the composite matrix as-cast strength. The research of microstructure showed the reason for increased joint strength and microhardness. The microstructural study showed the reason (4 %) for higher joint strength and microhardness. due to Significant of SiCp close to the boundary of the dynamically recrystallized and thermo mechanically affected zone (TMAZ) was observed through rotation speed 1800 rpm. The friction stir welded ultimate tensile strength Decreases as the volume fraction increases of SiCp (18 wt.%).

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