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Article
Publication date: 13 July 2012

M.F. Boseman, Y.W. Kwon, D.C. Loup and E.A. Rasmussen

In order to connect a fiberglass composite structure to a steel structure, a hybrid composite made of glass and steel fibers has been studied. The hybrid composite has one…

Abstract

Purpose

In order to connect a fiberglass composite structure to a steel structure, a hybrid composite made of glass and steel fibers has been studied. The hybrid composite has one end section with all glass fibers and the opposite end section with all steel fibers. As a result, it contains a transition section in the middle of the hybrid composite changing from glass fibers to steel fibers. The purpose of this paper is to examine interface strength at the glass to steel fiber transition section, in order to evaluate the effectiveness of the hybrid composite as a joining technique between a polymer composite structure and a metallic structure.

Design/methodology/approach

The present micromechanical study considers two types of glass to steel fiber joints: butt and overlap joints. For the butt joint, the end shape of the steel fiber is also modified to determine its effect on interface strength. The interface strength is predicted numerically based on the virtual crack closure technique to determine which joint is the strongest under various loading conditions such as tension, shear and bending. Numerical models include resin layers discretely. A virtual crack is considered inside the resin, at the resin/glass‐layer interface, and at the resin/steel‐layer interface. The crack is located at the critical regions of the joints.

Findings

Overall, the butt joint is stronger than the overlap joint regardless of loading types and directions. Furthermore, modification of an end shape of the middle fiber layers in the butt joint shifts the critical failure location.

Originality/value

The paper describes one of a few studies which investigated the interface strength of the hybrid joint made of fiberglass and steel‐fiber composites. This joint is important to connect a polymeric composite structure to a metallic structure without using conventional mechanical joints.

Details

Engineering Computations, vol. 29 no. 5
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 1 January 1992

ZHI‐HUA ZHONG and JAROSLAV MACKERLE

Contact problems are among the most difficult ones in mechanics. Due to its practical importance, the problem has been receiving extensive research work over the years…

Abstract

Contact problems are among the most difficult ones in mechanics. Due to its practical importance, the problem has been receiving extensive research work over the years. The finite element method has been widely used to solve contact problems with various grades of complexity. Great progress has been made on both theoretical studies and engineering applications. This paper reviews some of the main developments in contact theories and finite element solution techniques for static contact problems. Classical and variational formulations of the problem are first given and then finite element solution techniques are reviewed. Available constraint methods, friction laws and contact searching algorithms are also briefly described. At the end of the paper, a bibliography is included, listing about seven hundred papers which are related to static contact problems and have been published in various journals and conference proceedings from 1976.

Details

Engineering Computations, vol. 9 no. 1
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 18 February 2019

Peng Yao, Xiaoyan Li, Xu Han and Liufeng Xu

This study aims to analyze the shear strength and fracture mechanism of full Cu-Sn IMCs joints with different Cu3Sn proportion and joints with the conventional interfacial…

Abstract

Purpose

This study aims to analyze the shear strength and fracture mechanism of full Cu-Sn IMCs joints with different Cu3Sn proportion and joints with the conventional interfacial structure in electronic packaging.

Design/methodology/approach

The Cu-Sn IMCs joints with different Cu3Sn proportion were fabricated through soldering Cu-6 μm Sn-Cu sandwich structure under the extended soldering time and suitable pressure. The joints of conventional interfacial structure were fabricated through soldering Cu-100 μm Sn-Cu sandwich structure. After the shear test was conducted, the fracture mechanism of different joints was studied through observing the cross-sectional fracture morphology and top-view fracture morphology of sheared joints.

Findings

The strength of joints with the conventional interfacial structure was 26.6 MPa, while the strength of full Cu-Sn IMCs joints with 46.7, 60.6, 76.7 and 100 per cent Cu3Sn was, respectively, 33.5, 39.7, 45.7 and 57.9 MPa. The detailed reason for the strength of joints showing such regularity was proposed. For the joint of conventional interfacial structure, the microvoids accumulation fracture happened within the Sn solder. However, for the full Cu-Sn IMCs joint with 46.7 per cent Cu3Sn, the cleavage fracture happened within the Cu6Sn5. As the Cu3Sn proportion increased to 60.6 per cent, the inter-granular fracture, which resulted in the interfacial delamination of Cu3Sn and Cu6Sn5, occurred along the Cu3Sn/Cu6Sn5 interface, while the cleavage fracture happened within the Cu6Sn5. Then, with the Cu3Sn proportion increasing to 76.7 per cent, the cleavage fracture happened within the Cu6Sn5, while the transgranular fracture happened within the Cu3Sn. The inter-granular fracture, which led to the interfacial delamination of Cu3Sn and Cu, happened along the Cu/Cu3Sn interface. For the full Cu3Sn joint, the cleavage fracture happened within the Cu3Sn.

Originality/value

The shear strength and fracture mechanism of full Cu-Sn IMCs joints was systematically studied. A direct comparison regarding the shear strength and fracture mechanism between the full Cu-Sn IMCs joints and joints with the conventional interfacial structure was conducted.

Details

Soldering & Surface Mount Technology, vol. 31 no. 1
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 3 February 2020

Ye Tian, Heng Fang, Ning Ren, Chao Qiu, Fan Chen and Suresh Sitaraman

This paper aims to assess precise correlations between intermetallic compounds (IMCs) microstructure evolutions and the reliability of micro-joints with a…

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Abstract

Purpose

This paper aims to assess precise correlations between intermetallic compounds (IMCs) microstructure evolutions and the reliability of micro-joints with a Cu/SAC305solder/Ni structure using thermal shock (TS) tests.

Design/methodology/approach

This paper uses 200-µm pitch silicon flip chips with nickel (Ni) pads and stand-off height of approximately 60 µm, assembled on substrates with copper (Cu) pads. After assembly, the samples were subjected to air-to-air thermal shock testing from 55 to 125 per cent. The transfer time was less than 5 s, and the dwell time at each temperature extreme was 15 min. To investigate the microstructure evolution and crack growth, two samples were removed from the thermal shock chamber at 0, 400, 1,200, 2,000, 5,800 and 7,000 cycles.

Findings

The results showed that one (Cu, Ni)6Sn5/(Ni, Cu)3Sn4 dual-layer structure formed at the Ni pad interface of chip side dominates the micro-joints failure. This is because substantial (Ni, Cu)3Sn4 grain boundaries provide a preferential pathway for the catastrophic crack growth. Other IMCs microstructure evolutions that cause the prevalent joints failure as previously reported, i.e. thickened interfacial (Cu, Ni)6Sn5 and Ni3P layer, and coarsened IMCs inside the solder matrix, only contributed to the occurrence of fine cracks. Moreover, the typical interfacial IMCs spalling triggered by thermally induced stress did not take place in this study, showing a positive impact in the micro-joint reliability.

Originality/value

As sustained trends toward multi-functionality and miniaturization of microelectronic devices, the joints size is required to be constantly scaled down in advanced packages. This arises a fact that the reliability of small-size joints is more sensitive to the IMCs because of their high volume proportion and greatly complicated microstructure evolutions. This paper evaluated precise correlations between IMCs microstructure evolutions and the reliability of micro-joints with a Cu/SAC305solder/Ni structure using TS tests. It found that one (Cu, Ni)6Sn5/(Ni, Cu)3Sn4 dual-layer structure formed at the Ni pad interface dominate the micro-joints failure, whereas other IMCs microstructure evolutions that cause the prevalent joints failure exhibited nearly negligible effects.

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Article
Publication date: 4 March 2014

Mumin Sahin

The main purpose of the present study was to evaluate the metallurgical and mechanical properties of dissimilar metal friction welds (FWs) between aluminium and type 304…

Abstract

Purpose

The main purpose of the present study was to evaluate the metallurgical and mechanical properties of dissimilar metal friction welds (FWs) between aluminium and type 304 stainless steel.

Design/methodology/approach

One of the manufacturing methods used to produce parts made from different materials is the FW method. Therefore, in the present study, austenitic stainless steel and aluminium parts were joined by FW. Tensile, fatigue and notch-impact tests were applied to FW specimens, and the results were compared with those for the original materials. Microstructure, energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis and hardness variations were conducted on the joints.

Findings

It was found from the microstructure and XRD analysis that inter-metallic phases formed in the interface which further caused a decrease in the strength of the joints.

Research limitations/implications

In this study, the rotation speed was kept constant. The effects of the rotation speed on the welding quality can be examined in future. It is important to note that the FW process was successfully accomplished in this study although it was particularly difficult to obtain the weld due to the large deformations at the interface.

Practical implications

Low-density components such as aluminium and magnesium can be joined with steels owing to being cost-effective in industry. Application of classical welding techniques to such materials is difficult because they have different thermal properties. Their welding plays a key part in industrial quality and process control, in the efficient use of energy and other resources, in health and safety. Then, this study will contribute for welded, brazed and soldered materials.

Originality/value

The main value of this paper is to contribute and fulfill the influence of the interface on properties in welding of various materials that is being studied so far in the literature.

Details

Industrial Lubrication and Tribology, vol. 66 no. 2
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 1 March 1991

M.F. SNYMAN, W.W. BIRD and J.B. MARTIN

The paper considers a plane joint or interface element suitable for implementation into a standard non‐linear finite element code. Sliding of the joint is assumed to be…

Abstract

The paper considers a plane joint or interface element suitable for implementation into a standard non‐linear finite element code. Sliding of the joint is assumed to be governed by Coulomb friction, with a non‐associated flow rule and no cohesion. The constitutive equations are formulated in a manner appropriate for a backward difference discretization in time along the path of loading. It is shown that the backward difference assumption can lead to an explicit formulation in which no essential distinction need be drawn between opening and closing of the joint and sliding when the joint is closed. However, an inherent limitation of the dilatant Coulomb model becomes evident; the final formulation is internally consistent but does not describe reversed shear displacement in a physically reasonable way. Explicit equations for the consistent tangent stiffness and for the corrector step (or return algorithm) of the standard Newton—Raphson iterative algorithm are given. The equations have been implemented as a user element in the finite element code ABAQUS, and illustrative examples are given.

Details

Engineering Computations, vol. 8 no. 3
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 26 September 2008

Hilmi Kuscu, Ismail Becenen and Mumin Sahin

The purpose of this paper is to evaluate temperature and properties at interface of AISI 1040 steels joined by friction welding.

Abstract

Purpose

The purpose of this paper is to evaluate temperature and properties at interface of AISI 1040 steels joined by friction welding.

Design/methodology/approach

In this study, AISI 1040 medium carbon steel was used in the experiments. Firstly, optimum parameters of the friction welding were obtained by using a statistical analysis. Later, the microstructures of the heat‐affected zone are presented along with micro hardness profiles for the joints. Then, the temperature distributions are experimentally obtained in the interface of the joints that is formed during the friction welding of 1040 steels with the same geometry. This study was carried out by using thermocouples at different locations of the jointinterface. The results obtained were compared with previous studies and some comments were made about them.

Findings

It was discovered that temperature had a substantial effect on the mechanical and metallurgical properties of the material.

Research limitations/implications

The maximum temperature in the joint during frictional heating depends not only on the pressure, but also on the temperature gradient which depends on the rotational speed in particular. It is important to note that the measurement process was successfully accomplished in this study although it was particularly difficult to obtain temperature due to the large deformations at the interface. Future work could be concentrated on the temperature measurement of the joined materials.

Practical implications

Temperature is one of the most important of all physical quantities in industry. Its measurement plays a key part in industrial quality and process control, in the efficient use of energy and other resources, in condition monitoring and in health and safety. This paper contributes to the literature about temperature measurement in welded, brazed and soldered materials.

Originality/value

The main value of this paper is to contribute and fulfill the influence of the interface temperature on properties in welding of various materials that is being studied so far in the literature.

Details

Assembly Automation, vol. 28 no. 4
Type: Research Article
ISSN: 0144-5154

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Article
Publication date: 20 August 2019

Ghadanfer Hussein Ali and Sabah Khammass Hussein

The purpose of this paper is to join an anodized aluminium alloy AA6061 sheet with high-density polyethylene (HDPE) using friction spot process.

Abstract

Purpose

The purpose of this paper is to join an anodized aluminium alloy AA6061 sheet with high-density polyethylene (HDPE) using friction spot process.

Design/methodology/approach

The surface of AA6061 sheet was anodized to increase the pores’ size. A lap joint configuration was used to join the AA6061 with HDPE sheets by the friction spot process. The joining process was carried out using a rotating tool of different diameters: 14, 16 and 18 mm. Three tool-plunging depths were used – 0.1, 0.2 and 0.3 mm – with three values of the processing time – 20, 30 and 40 s. The joining process parameters were designed according to the Taguchi approach. Two sets of samples were joined: the as-received AA6061/HDPE and the anodized AA6061/HDPE.

Findings

Frictional heat melted the HDPE layers near the lap joint line and penetrated it through the surface pores of the AA6061 sheet via the applied pressure of the tool. The tool diameter exhibited higher effect on the joint strength than processing time and the tool-plunging depth. Specimens of highest and lowest tensile force were failed by necking the polymer side and shearing the polymer layers at the lap joint, respectively. Molten HDPE was mechanically interlocked into the pores of the anodized surface of AA6061 with an interface line of 18-m width.

Originality/value

For the first time, HDPE was joined with the anodized AA6061 by the friction spot process. The joint strength reached an ideal efficiency of 100 per cent.

Details

World Journal of Engineering, vol. 16 no. 4
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 2 April 2019

Roman Koleňák, Igor Kostolný, Jaromír Drápala, Martin Kusý and Matej Pašák

This study aims to solder AlN ceramics with a Cu substrate using an active type Sn-Ag-Ti solder. Soldering was performed with power ultrasound. The Sn3.5Ag2Ti alloy was…

Abstract

Purpose

This study aims to solder AlN ceramics with a Cu substrate using an active type Sn-Ag-Ti solder. Soldering was performed with power ultrasound. The Sn3.5Ag2Ti alloy was first studied.

Design/methodology/approach

It was found to contain a Sn matrix, where both Ag phase – ɛ-Ag3Sn – and Ti phases ɛ-Ti6Sn5 and Ti2Sn3 – were identified. Ti contained in these phases is distributed to the interface with ceramic material. A reaction layer was thus formed. This layer varies in thickness from 0.5 to 3.5 µm and ensures the wettability of an active solder on the surfaces of ceramic materials.

Findings

X-ray diffraction analysis proved the presence of new NTi and AlTi2 phases on the fractured surface. Sn plays the main role in bond formation when soldering the Cu substrate with Sn-Ag-Ti solder. The Cu3Sn and Cu6Sn5 phases, which grow in direction from the phase interface to solder matrix, were found in all cases within the solder/Cu substrate interface. The combination of AlN ceramics/Cu joint maintained a shear strength of 29.5 MPa, whereas the Cu/Cu joint showed a somewhat higher shear strength of 39.5 MPa.

Originality/value

The present study was oriented towards soldering of AlN ceramics with a Cu substrate by the aid of ultrasound, and the fluxless soldering method was applied. Soldering alloy type Sn-Ag-Ti was analysed, and the interactions between the solder and ceramic and/or Cu substrate were studied. The shear strength of fabricated soldered joints was measured.

Details

Soldering & Surface Mount Technology, vol. 31 no. 2
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 13 January 2021

Gui-sheng Gan, Liujie Jiang, Shiqi Chen, Yongqiang Deng, Donghua Yang, Zhaoqi Jiang, Huadong Cao, Mizhe Tian, Qianzhu Xu and Xin Liu

Low-Ag SAC solder will lead to a series of problems, such as increased the melting range and declined the solderability and so on. These research studies do not have too…

Abstract

Purpose

Low-Ag SAC solder will lead to a series of problems, such as increased the melting range and declined the solderability and so on. These research studies do not have too much impact on the improvement of solders’ performance but were difficult to achieve satisfactory results. It is urgent to develop new soldering technology to avoid the bottleneck of lead-free solder. low-temperature-stirring soldering and ultrasonic-assisted soldering was developed in the authors’ early work, but slag inclusion and pore would gather and grow up to lead decreasing of the shear strength. In this paper, Cu/SAC0307 +Zn power/Cu joints with ultrasonic-assisted at low-temperature was successfully achieved.

Design/methodology/approach

45um Zn-powder and SAC0307 No.4 solder powder were mixed to fill the Cu-Cu joint, and the content of Zn-powder were 0 and 5%, 7.5% and 10%, 12.5% and 15% respectively. During the soldering process under ambient atmosphere %252C the heating platform provided a constant 220%253 F and the ultrasonic vibrator applied a constant pressure of 4 MPa to the copper substrate. The soldering process was completed after holding 70 s at 300 W.

Findings

The Zn particles made the IMC at the joint interface and in the soldering seam from scallop-type Cu6Sn5 to flat-type Cu5Zn8. The shear strength of joints without Zn was only 12.43 MPa, the shear strength of joints with 10% Zn reached a peak of 34.25 MPa, and the shear strength of joints containing 10% Zn was 63.71% higher than that of joints without zinc particles, and then the shear strength decreased. In addition, with the increase of zinc content, the fracture mode of the joint changed from the brittle fracture of the original layered tears to the mixed tough and brittle fracture.

Originality/value

A new method that Zn micron-size powders and SAC0307 micron-size powders was mixed to fill the joint, and successfully achieved micro-joining of Cu/Cu under ultrasonic-assisted without flux at low-temperature.

Details

Soldering & Surface Mount Technology, vol. 33 no. 4
Type: Research Article
ISSN: 0954-0911

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