Low Temperature Soldering of Laser Structured and Metal Coated Fiber Reinforced Plastics

2021 ◽  
Author(s):  
K. Gustke ◽  
D. Kupke ◽  
R. Drehmann ◽  
T. Lampke ◽  
J. Gebauer ◽  
...  
Keyword(s):  
Low Temperature ◽  
Adhesive Bonding ◽  
Arc Spraying ◽  
Fiber Reinforced ◽  
Mechanical Joining ◽  
Metal Parts ◽  
Reinforced Plastics ◽  
Reinforced Plastic ◽  
Wire Arc Spraying ◽  
Plastic Parts

Abstract Assemblies containing fiber-reinforced plastic (FRP) and metal parts are typically fastened together via mechanical joining or adhesive bonding. Mechanical joining processes tend to weaken FRP parts by cutting fibers, while adhesives require long cures and often lead to inseparable material compounds. This paper evaluates a new joining method in which plastic parts are laser treated, then metallized via wire-arc spraying, and finally soldered to mating metal parts using a low-temperature process. Due to the effective increase in interface area resulting from laser structuring, bond strengths of up to 15.5 MPa can be achieved.

scholarly journals Cold surface treatments on fiber-reinforced plastics by pulsed laser

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Jana Gebauer ◽  
Gerd Paczkowski ◽  
Jodok Weixler ◽  
Udo Klotzbach
Keyword(s):  
Adhesive Bonding ◽  
New Technologies ◽  
Thermal Spraying ◽  
Fiber Reinforced ◽  
Cold Surface ◽  
Promising Alternative ◽  
Reinforced Plastics ◽  
Reinforced Plastic ◽  
Matrix Removal ◽  
Fiber Reinforced Plastics

When producing fiber-reinforced plastic (FRP) suitable for mass production, new technologies have to be developed to overcome existing challenges such as increased efficiency in resource consumption or higher process flexibility. In the past, laser processing has been shown to yield important advantages such as non-contact processing, no tool wear and high design flexibility.Pulsed laser ablation of FRP offers a promising alternative to state of the art mechanical blasting. The selective matrix removal enables a high potential to improve adhesive bonding, molding processes and coating deposition of lightweight materials, especially FRP-metal or FRP-ceramic hybrids. The resulting increase in surface area exhibits forms lock characteristics and simultaneously provides an expanded interface area. As a result, 40 % higher tensile strength can be reached in pull-off tests compared to a mechanically blasted organic sheet surface, joined by thermal spraying of aluminum on carbon fiber-reinforced epoxy (CFRP).

Effect of Interfacial Nanostructure on Mode Mixity in Directly Bonded Carbon Fiber Reinforced Thermoplastic Laminates and Aluminum Alloy With Thermal Stresses

2020 ◽  
Author(s):  
Hiroki Ota ◽  
Kristine Munk Jespersen ◽  
Kei Saito ◽  
Keita Wada ◽  
Kazuki Okamoto ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Aluminum Alloy ◽  
Carbon Fiber ◽  
Residual Stresses ◽  
Adhesive Bonding ◽  
Thermal Stresses ◽  
Fiber Reinforced ◽  
Mode Mixity ◽  
Mechanical Joining ◽  
Carbon Fiber Reinforced

Abstract In recent years, for the aim of weight reduction of transportation equipment, carbon fiber reinforced thermoplastics (CFRTPs), which have high recyclability and formability, are becoming suitable for mass production. Additionally, with the development of multi-material structures, excellent technologies for joining metal and CFRTPs are required. In present industry, joining between dissimilar materials include adhesive bonding and mechanical joining methods, however, these methods still have some problems, and therefore an alternative bonding method without adhesive and mechanical joining is required for joining CFRTPs and metals. Thus, this study focused on direct bonding between CFRTP and an aluminum alloy, by producing a nanostructure on the surface of the aluminum alloy. The nanostructure penetrates the CFRTP matrix causing an anchoring effect, which results in significant bonding strength improvement. The influence of the nanostructure on the fracture toughness for the directly bonded CFRTP and aluminum was evaluated by static double cantilever beam (DCB) testing. Due to the difference of the thermal expansion coefficients between the CFRTP laminates and the aluminum alloy, significant residual stresses are generated. The effect of the thermal residual stresses on the fracture toughness along with the resulting mode mixity (mode I and II) was calculated. It is found that the thermal stresses introduce a significant mode mixity of the fracture toughness.

Smart Crash Management by Switching the Crash Behavior of Fiber-Reinforced Plastic (FRP) Energy Absorbers With Shape Memory Alloy (SMA) Wires

2013 ◽  
Author(s):  
Moritz Hübler ◽  
Sebastian Nissle ◽  
Martin Gurka ◽  
Sebastian Schmeer ◽  
Ulf Paul Breuer
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Essential Element ◽  
Load Level ◽  
Switching Behavior ◽  
Fiber Reinforced ◽  
Reinforced Plastics ◽  
Reinforced Plastic ◽  
Energy Absorbers ◽  
Energy Absorbing

In this paper two innovative concepts for adjustable energy absorbing elements are presented. These absorbers can serve as an essential element in a smart crash management system e.g. for automotive applications. The adaptability is based on the basic idea of adjusting the stiffness of the absorber in relation to the actual load level in a crash event. Therefore the whole length of the absorber element can be used for energy dissipation. The adjustable absorbers are made from fiber reinforced plastics and shape memory alloy wires as actuating elements. Two possibilities for the basic design of the absorber elements are shown, the performance of the actuating SMA elements is characterized in detail and the switching behavior of the whole elements, between a stiff “on” state and a flexible “off” state, is measured.

Z-pin insertion process for through-thickness reinforced thermoplastic composites

2018 ◽  
Vol 53 (2) ◽  
pp. 173-181 ◽  
Author(s):  
Julian Hoffmann ◽  
Alexander Brast ◽  
Gerhard Scharr
Keyword(s):  
Thermoplastic Composites ◽  
Fiber Reinforced ◽  
Fiber Waviness ◽  
Reinforced Plastics ◽  
Pullout Tests ◽  
Glass Fiber Reinforced ◽  
Reinforced Plastic ◽  
Novel Method ◽  
Fiber Reinforced Plastics ◽  
Insertion Process

This paper presents a novel method for the ultrasonically assisted insertion of metallic z-pins into thermoplastic composites. Mechanical and microstructural investigations were carried out on glass fiber-reinforced polyamide and polypropylene specimens. The insertion of steel pins into thermoplastic composites led to microstructural changes that differ significantly from the known microstructure of z-pinned thermoset fiber-reinforced plastics. Optical microscopy showed an absence of notable fiber waviness and resin-rich zones around each pin. Instead, the fibers were predominantly deflected in the through-thickness direction by the high insertion forces arising during pin penetration. To gain an initial insight on the resulting properties of the z-pin/thermoplastic interface, the mechanical properties of z-pinned thermoplastic composites under mode I loading were investigated using pullout tests. For reference, the pullout behavior of thermoset carbon fiber-reinforced plastic specimens, reinforced with steel pins was determined too. Due to the poor bonding and lack of friction between the pin and laminate, the determined traction loads of the thermoplastic specimens are well below typical values achieved from pin pullout in thermoset laminates.

Study on Acoustic Emission Detection Technology of Fiber Reinforced Plastic Pressure Vessel

2020 ◽  
Author(s):  
Daoxiang Wei ◽  
Yuqing Yang ◽  
Jun Si ◽  
Xiang Wen
Keyword(s):  
Acoustic Emission ◽  
Pressure Vessel ◽  
Pressure Vessels ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Glass Fiber Composites ◽  
Reinforced Plastics ◽  
Detection Technology ◽  
Reinforced Plastic ◽  
Emission Detection

Abstract Fiber reinforced plastics are used in pressure vessel manufacturing because of their high strength and corrosion resistance.Defects may occur in the manufacture and use of the pressure vessel. To ensure safe operation of the pressure vessel, it is necessary to conduct periodic safety assessment of the pressure vessel put into operation. It is difficult to evaluate the safety status of fiber-reinforced plastic pressure vessels by conventional nondestructive testing.Acoustic emission detection technology is a dynamic detection method, which has obvious advantages for the performance and fracture process of fiber reinforced plastic materials. ASME section V or ASTM section on acoustic emission detection of FRP pressure vessels, in which the localization of defects is mainly based on acoustic emission instruments. Due to the anisotropy of FRP material, the instrument can only give the area of the defect, and then use other non-destructive testing methods supplementary detection, so the author proposes a regional positioning method, which can locate defects more accurately. In this paper, acoustic emission detection method and lead breaking method were used to simulate the deficiency, and acoustic velocity attenuation and variation of fiber reinforced plastics were studied, and confirmative tests were carried out to obtain the positioning accuracy of the deficiency in different areas.In order to achieve the acoustic emission (AE) response behavior of stretching damage of glass fiber composites with fiber pre-broken and weak bonding, stretching tests and real-time AE monitoring of glass fiber composites were conducted.Experimental results showed that damage model such as matrix cracking and fiber fracture and bending could be occurred in the process of damage and failure. The composition and content of signal frequency of AE is also different because of difference of preset defect.

Surface Pretreatment of Fiber-Reinforced Plastics via VUV Radiation

2017 ◽  
Vol 742 ◽  
pp. 70-73
Author(s):  
Christoph Schmüser ◽  
Kira Rosanova ◽  
Christopher Dölle
Keyword(s):  
Surface Energy ◽  
Power Plants ◽  
Adhesive Bonding ◽  
Surface Preparation ◽  
Transport Sector ◽  
Contact Method ◽  
Fiber Reinforced ◽  
Release Agent ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics

Fiber-reinforced plastics (FRP) are of great importance for the transport sector, the aerospace industry, for wind power plants, in the building sector and in the field of sports and leisure applications. Optimization of the adhesive bonding process for FRP structures, especially the surface preparation prior to bonding, will be of a central importance in forthcoming expansion of FRP use. In this connection the key problem depends on the FRP polymer matrix. In the case of duroplastic matrix the main problem is the presence of release agent on the surface of joining components. For the thermoplastic matrix such as polypropylene (PP), the main problems are the low surface energy and the inertness of its surface. Conventional pretreatment methods, such as manual grinding, shall be replaced by energetic radiation technics like VUV lamps (vacuum ultraviolet spectral range: 100 – 200 nm). This approach is a non-contact method, characterized by high treatment homogeneity and material-saving properties, combined with no further fibers to be released. The surface of the thermoplastics is activated by the incorporation of oxygen, release agent contamination on the thermoset is cleaned or modified [1 - 8]. The results of the VUV surface activation of PP and CFRP with regard to the incorporation of functional groups, increase of surface energy, matrix degradation and the adhesion increase of adhesive bonds are presented. In addition, studies on the release agent coating and the release agent modification by VUV radiation are presented. The work is completed by considerations concerning possibilities to accelerate the process (in particular, wavelength dependence, influence of an inert gas or the moisture content). Finally, an evaluation of the VUV pretreatment is carried out on the basis of two specific applications.

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