Cold Pressure Welding—The Mechanisms Governing Bonding

1979 ◽  
Vol 101 (2) ◽  
pp. 121-127 ◽  
Author(s):  
N. Bay
Keyword(s):  
Surface Layer ◽  
Bond Strength ◽  
Normal Pressure ◽  
Experimental Investigations ◽  
Virgin Material ◽  
Pressure Welding ◽  
Real Contact ◽  
Basic Parameters ◽  
Surface Expansion ◽  
Cold Pressure

Investigations of the bonding surface in scanning electron microscope after fracture confirm the mechanisms of bond formation in cold pressure welding to be: fracture of work-hardened surface layer, surface expansion increasing the area of virgin surface, extrusion of virgin material through cracks of the original surface layer, and establishment of real contact and bonding between virgin material. This implies that normal pressure as well as surface expansion are basic parameters governing the bond strength. Experimental investigations of pressure welding Al-Al under plane strain compression in a specially developed equipment allowing independent variation of normal pressure and surface expansion confirm this. Based upon a slip-line analysis of the extrusion through cracks of the surface layer and upon the establishment of real contact between virgin material, a theory for the bond strength as a function of surface expansion and normal pressure is developed. The theory is in good agreement with the experimental results.

Interfacial conditions and bond strength in cold pressure welding by rolling

1978 ◽  
Vol 5 (1) ◽  
pp. 24-31 ◽  
Author(s):  
P. K. Wright ◽  
D. A. Snow ◽  
C. K. Tay
Keyword(s):  
Bond Strength ◽  
Pressure Welding ◽  
Interfacial Conditions ◽  
Cold Pressure

Brushing for High Performance Cold Pressure Welded Bonds

2018 ◽  
Vol 767 ◽  
pp. 309-315 ◽  
Author(s):  
Christiane Gerlitzky ◽  
Stefan Volz ◽  
Peter Groche
Keyword(s):  
Bond Strength ◽  
High Performance ◽  
Crack Formation ◽  
Tensile Tests ◽  
Material Strength ◽  
Pressure Welding ◽  
High Bond ◽  
Bond Strengths ◽  
Aluminum Surfaces ◽  
Cold Pressure

Joining of steel and aluminum is a commonly applied manufacturing process to obtain lightweight components. Cold pressure welding by means of direct extrusion allows gaining high bond strengths between these two materials. The contacting surfaces are usually prepared by using scratch brushing to enhance the bond strength. Most studies have shown the benefit of the brushing whereas the resulting bond strength scatters. Variations in the parameters of the brush treatment are presumed to be a major cause for the variations in strength. Within the presented work, scratch brushing parameters are adjusted to further improve the resulting bond strength. Cracking of the surfaces at low strains is a beneficial effect to enhance the bond strength. Therefore, the crack formation of the surfaces brushed under different conditions is analyzed in tensile tests. Roughness, residual stresses and microstructural changes of the aluminum surfaces resulting from brushing processes are evaluated to enhance the understanding of the cracking mechanism. Concluding, the brushing parameters are adjusted to improve bond strengths up to the material strength of the used aluminum.

scholarly journals The influence of silicon in EN AW 6082 alloys on the bond strength in cold pressure welding

2019 ◽  
Author(s):  
Christiane Gerlitzky ◽  
Siri Marthe Arbo ◽  
Ida Westermann ◽  
Peter Groche
Keyword(s):  
Bond Strength ◽  
Pressure Welding ◽  
Cold Pressure

The Microhardness and Microstructural Changes of Mechanically Affected Zone by Cold Pressure Welding in Aluminum Rod

2014 ◽  
Vol 52 (9) ◽  
pp. 721-729
Author(s):  
Seul Gi Hwang ◽  
Jeong Hyun Jo ◽  
Shang shu Kim ◽  
Young ho Lee ◽  
Jae Kwan Ku
Keyword(s):  
Pressure Welding ◽  
Microstructural Changes ◽  
Cold Pressure

Studies on Cold Pressure Welding (Report 1)

1959 ◽  
Vol 28 (5) ◽  
pp. 331-338
Author(s):  
T. Saito ◽  
K. Yamaji
Keyword(s):  
Pressure Welding ◽  
Cold Pressure

scholarly journals The Interfacial Characterization and Performance of Cu/Al-Conductive Heads Processed by Explosion Welding, Cold Pressure Welding, and Solid-Liquid Casting

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 237 ◽  
Author(s):  
Yanni Wei ◽  
Hui Li ◽  
Fu Sun ◽  
Juntao Zou
Keyword(s):  
Corrosion Resistance ◽  
Bonding Strength ◽  
Explosive Welding ◽  
Slag Inclusion ◽  
Explosion Welding ◽  
Bonding Interface ◽  
Pressure Welding ◽  
And Performance ◽  
Solid Liquid ◽  
Cold Pressure

The Cu/Al composites conductive head is widely used in hydrometallurgy as the core component of cathode plate. Its conductive properties directly affect the power consumption, and the bonding strength and corrosion resistance determine the conductive head service life. The Cu/Al conductive head prepared by explosion welding, cold pressure welding, and solid-liquid casting methods were investigated in this paper. The interface microstructure and compositions were examined by scanning electron microscope and X-ray energy dispersive spectrometry. The bonding strength, interface conductivity, and the corrosion resistance of three types of joints were characterized. The Cu/Al bonding interface produced by explosive welding presented a wavy-like morphology with typical defects and many of brittle compounds. A micro-interlocking effect was caused by the sawtooth structures on the cold pressure welding interface, and there was no typical metallurgical reaction on the interface. The Cu/Al bonding interface prepared by solid-liquid casting consisted mainly of an Al-Cu eutectic microstructure (Al2Cu+Al) and partial white slag inclusion. The thickness of the interface transition layer was about 200–250 µm, with defects such as holes, cracks, and unwelded areas. The conductivity, interfacial bonding strength, and corrosion resistance of the conductive head prepared by explosive welding were superior to the other two.

Criteria for Best Performance of Pre-Optimized Solid Dampers

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Chiara Gastaldi ◽  
Muzio M. Gola
Keyword(s):  
High Performance ◽  
Nonlinear Finite Element ◽  
Design Stage ◽  
Experimental Investigations ◽  
Early Design Stage ◽  
Real Contact ◽  
Starting Point ◽  
Definition Of ◽  
Stiffening Effect ◽  
Contact Parameters

This paper furthers recent research by these authors. The starting point is the pre-optimization of solid dampers, which ensures that all dampers bound to “misbehave” are excluded since the early design stage. The authors now enlarge the scope of their investigations to explore those damper configurations selected inside the admissible design area. The purpose of the paper is to present a set of criteria apt to select a damper configuration which not only avoids unwanted situations, but in addition guarantees high performance under different design conditions. The analysis starts with the definition of a set of requirements a high performance damper should meet. In detail, the present investigation seeks to answer the following questions: in the low excitation regime, what is the frequency shift and the stiffening effect each damper can provide? for increasing excitation levels, which damper will start slipping sooner? in the high excitation regime, which damper provides the maximum dissipation? Like pre-optimization, it does not involve nonlinear finite element calculations, and unlike existing optimization procedures, is not linked to a specific set of blades the damper may be coupled to. The numerical prediction of the blade-damper coupled dynamics is here used only for validation purposes. The approach on which this paper rests is fully numerical; however, real contact parameters are taken from extensive experimental investigations made possible by those purposely developed test rigs which are the distinctive mark of the AERMEC Lab of Politecnico di Torino.

scholarly journals Quality assurance of ring gear in cylindrical wheels at processing with combined grinding-polishing worm disk

2019 ◽  
Vol 2018 (2) ◽  
pp. 22-28
Author(s):  
Владимир Макаров ◽  
Vladimir Makarov ◽  
Наталья Ворожцова ◽  
Natalia Vorozhtsova ◽  
Александр Горбунов ◽  
...  
Keyword(s):  
Quality Assurance ◽  
Surface Layer ◽  
Quality Parameters ◽  
Experimental Investigations ◽  
Ring Gear ◽  
Micro Hardness ◽  
Gear Grinding ◽  
Gear Honing ◽  
Surface Residual Stresses ◽  
Comparative Results

The investigation results of technological potentialities in the finish gear grinding of a ring gear of cylindrical wheels with the combined grinding-polishing worm disk with the assurance of geometrical accuracy and quality parameters of a surface layer are shown. The comparative results of experimental investigations of the structure of surface micro-hardness, its depth and surface residual stresses at cog-wheels finish processing with gear honing and gear polish are given.

Criteria for Best Performance of Pre-Optimized Solid Dampers

2018 ◽  
Author(s):  
Chiara Gastaldi ◽  
Muzio M. Gola
Keyword(s):  
High Performance ◽  
Nonlinear Finite Element ◽  
Design Stage ◽  
Experimental Investigations ◽  
Early Design Stage ◽  
Real Contact ◽  
Starting Point ◽  
Definition Of ◽  
Stiffening Effect ◽  
Contact Parameters

This paper furthers recent research by these authors. The starting point is the pre-optimization of solid dampers, which ensures that all dampers bound to misbehave are excluded since the early design stage. The authors now enlarge the scope of their investigations to explore those damper configurations selected inside the admissible design area. The purpose of the paper is to present a set of criteria apt to select a damper configuration which not only avoids unwanted situations, but in addition guarantees high performance under different design conditions. The analysis starts with the definition of a set of requirements a high performance damper should meet. In detail the present investigation seeks to answer the following questions: – in the low excitation regime, what is the frequency shift and the stiffening effect each damper can provide? – for increasing excitation levels, which damper will start slipping sooner? – in the high excitation regime, which damper provides the maximum dissipation? Like pre-optimization, it does not involve nonlinear Finite Element calculations, and unlike existing optimization procedures, is not linked to a specific set of blades the damper may be coupled to. The numerical prediction of the blade-damper coupled dynamics is here used only for validation purposes. The approach on which this paper rests is fully numerical, however real contact parameters are taken from extensive experimental investigations made possible by those purposely developed test rigs which are the distinctive mark of the AERMEC Lab of Politecnico di Torino.

scholarly journals IMPROVEMENT OF MACHINE SAFETY DEVICES

2018 ◽  
Vol 58 (1) ◽  
pp. 17 ◽  
Author(s):  
Bohdan Matviiovych Hevko ◽  
Roman Bohdanovych Hevko ◽  
Oleksandra Mykolaivna Klendii ◽  
Mykola Vasyliovych Buriak ◽  
Yurii Volodymyrovych Dzyadykevych ◽  
...  
Keyword(s):  
Optimum Design ◽  
Test Bench ◽  
Theoretical Calculations ◽  
Experimental Investigations ◽  
Dynamic Parameters ◽  
Safety Devices ◽  
Basic Parameters ◽  
Machine Safety ◽  
Made In ◽  
New Machine

The article presents a development of new machine safety devices, which provide protection of operating elements from overload. Theoretical calculations have been made in order to determine the optimum design, kinematic and dynamic parameters of safety devices. A test bench has been developed and experimental investigations have been conducted in order to determine basic parameters of overload clutches.

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