Soldering Brazing | EWI - Materials Joining, Forming, Testing, Modeling, and Engineering Consulting Services

Archives For Soldering Brazing

Friction Stir Welding of 25-mm Thick Steel

Brian Thompson — June 6, 2013 — Leave a comment

At the forefront of research and development in Friction Stir Welding is the successful joining of high melting temperature materials such as steel. Recent studies have report significant costs savings when using FSW to join thicker section steel. While FSW typically travels slower than traditional arc welding processes, it is capable of joining thicker sections in a single pass. This one pass capability can translate into significant cost savings when constructing large steel structures such as oil and gas pipelines, off shore platforms, or heavy machinery.

fig 1 25mm Thick

fig 2 post-weld-image 25mmFSW
Until now, the thickest weld made by FSW reported in open literature has been 19-mm thick. Using advanced tungsten based materials, EWI conducted a series of feasibility trials to push the depths of FSW to 25-mm thick in a single pass. A series of development welds were made on 25-mm thick steel plate with a yield strength of 70-ksi. A fully consolidated weld joint was finally achieved using welding parameters of 135 RPM and 1.75-IPM (Figure 1). Most notably, the post-weld distortion was immeasurable (Figure 2) and the cross-weld mechanical properties at 25-mm thick were comparable to those tested at thinner sections (Figure 3).

x7- steel property comparison

A more detailed summary of the work EWI has been conducting to push the limits of FSW technology in steel will be presented at ISOPE 2013 in Anchorage, Alaska on July 2nd 2013.

In Aerospace, Arc Welding, Automotive, Consumer Goods, Corporate Blog, DCA, Defense, Energy, Friction Process, Government, Heavy Industry, Materials Engineering, Resistance Processes, Soldering Brazing, Structural Integrity, Ultrasonic Processes

SCC/HE of Bolts/Fasteners in Marine Environments

Jose Ramirez — February 26, 2013 — Leave a comment

In the oil and gas industry, bolted connections are often used for high integrity systems and are thus vital for the long term performance of the given structure. As the oil and gas industry explores and develops reservoirs in deeper waters where operation and intervention costs are exceptionally high, factors such as bolt/fastener design, proper material selection, materials and bolts/fastener processing, and installation of bolts/fasteners become more important to provide the required service life for the various exposure and service conditions.

Fasteners can fail as result of one or a combination of overload, corrosion, fatigue, corrosion fatigue, or environment assisted cracking (EAC) in the form of stress corrosion cracking (SCC) or hydrogen embrittlement (HE). SCC is a localized corrosion attack that propagates rapidly leading to failure of components and potentially the associated structures. SCC / HE are failure mechanisms resulting from the synergistic effect of the environment, presence of tensile stresses, and material susceptibility.

In marine environments, chlorides can act as a catalyst for chloride SCC. Hydrogen generated by corrosion reactions or cathodic overprotected systems can induce HE. Potential sources of tensile stresses in bolts/fasteners include stress applied during tightening or torquing, and residual stress from different manufacturing processes (forging or casting, surface treatment, heat treatments, forming, machining, and cutting and shearing). Mechanical properties and resistance to corrosion and EAC are critical factors for the selection of materials for bolts and fasteners in the marine application. The corrosion protection of the bolts depends on the intrinsic corrosion resistance of the bolting material and the effect of any supplementary protection measures. Such measures can include coating systems and/or cathodic protection. Available materials for subsea high-strength bolts or fasteners includes high-strength low alloy steels, stainless steels, nickel-based alloys, Cobalt-Ni alloys, beryllium-cupper alloys, and titanium alloys. High strength steels, mainly AISI 4140 and 4340, remain the most common materials for subsea fasteners.

As higher-pressure systems are being built in subsea environments large diameter fasteners made with higher-strength materials are being used. High-strength low alloy steels may provide adequate corrosion resistance in cathodic protected systems, but their resistance to SCC or HE is a concern. High-strength steel may be more susceptible to HE in seawater under cathodic protection, and the susceptibility increases with strength.
The SCC resistance of these materials to particular environments is generally expressed in maximum hardness limits.Therefore, adhering to specifications and quality assurance should be a prime concern in bolt/fastener procurement. Selectionfor subsea application still relies in qualification testing for the specific application. The oil industry challenge is to develop reliable test methods for materials qualifications and to assess the risk to HE. Experiences in the field indicate that the main drivers for bolting material HE have been susceptible microstructures, CP, and applied load levels.

EWI Named Top Ten Company on List of Ohio Innovators

Rebecca Gurk — January 4, 2013 — 1 Comment

I just heard that EWI was listed on COLUMBUS BUSINESS FIRST’s prestigious “Central Ohio Innovators” list in 2012. While this may not be a surprise to EWI associates and partners, its great recognition for the leading-edge work – including nine patents between 2006 and 2010 – developed by our small corps of engineers.

COLUMBUS BUSINESS FIRST ranked EWI among such prestigious organizations as Honda of America, The Ohio State University, Battelle, and Nationwide Children’s Hospital – good R&D company, for sure! The journal also gave a special callout to our patent for ultrasonic additive manufacturing, which served as the basis for the partnership between EWI and its newly-formed spinout company Fabricsonic LLC.

To see the list, go to http://digital.bizjournals.com/launch.aspx?eid=cbdd003b-6013-46ca-a599-d3c290375f46&loc=pcmod.

Congrats to our talented team of trailblazers!

EWI Establishes New Forming Center

Rebecca Gurk — November 16, 2012 — Leave a comment

EWI announces the launch of the EWI Forming Center, established to focus on sheet metal forming and forging processes. Under the leadership of Director Ron Brown of EWI, Chairman Taylan Altan of the Ohio State University Center for Precision Forming (OSU-CPF), and Technical Director Hyunok Kim of EWI, the new center addresses issues in forming and allied technologies for automotive, aerospace and other manufacturing industries.

The EWI Forming Center is a collaborative endeavor, the first of its kind in the United States. Its mission is to develop and advance innovative metal forming processes, tooling, and equipment, and to provide a technology and knowledge base to industry. In doing so, the center is working and in cooperation with the Ohio State University Center for Precision Forming. The center’s inaugural event, a joint workshop with OSU-CPF on Advance Sheet Metal Forming Technology, was held at EWI headquarters on November 14. More than 60 participants from industry and academia attended.

Supported by a broad array of resources, the EWI Forming Center is unique in its capacity to provide forming, modeling, and joining-related services to manufacturers. “EWI’s capabilities create an unmatched combination of expertise in testing, modeling, and simulation-based engineering to provide practical solutions for stamping and forging applications,” says Ron Brown, Center Director. “We are excited about the opportunity to enhance our customers’ manufacturing competitiveness through the capabilities of the EWI Forming Center.”

For more information about the EWI Forming Center, contact Ron Brown at rbrown@ewi.org or 614.688.5085.

Lighten Up – Joining Technology for Lightweighting

Steve Massey — November 2, 2012 — Leave a comment

Lightweighting is an important focus for design folks in the automotive and aerospace worlds. Reducing the weight of a vehicle helps to improve fuel economy and reducing the weight of an airplane additionally enables more cargo to be carried. Magnesium-Aluminum-Zinc (Mg-Al-Zn) alloys have the highest strength to weight ratios of structural metals. AZ31B (Mg-3Al-1Zn) is 35-percent less dense than aluminum, but has 89-percent of the strength of 6061-T6 aluminum.

One of the challenges when trying to join Mg is that it rapidly oxidizes at temperatures above 400-degrees Celcius as the image below shows.

Through our unique soldering approach, EWI has been able to join Mg to both aluminum and steel with very limited oxidation.

Shown below are cross sections of a Mg to steel joint. The first one is shown with no magnification and the second shows the bond line at 50x magnification.

Here are the cross sections of a Mg to Al joint. The first one is shown with no magnification and the second shows the bond line at 50x magnification.

If you would like more information on joining solutions for lightweighting, or dissimilar metals joining, please contact Kirk Cooper of the EWI Materials Group.

You can reach Kirk at 614.688.5000 or kcooper@ewi.org.

You can also contact me, Steve Massey, at smassey@ewi.org.

Thanks for your interest in EWI.

Get it Right – It’s Movember!

Steve Massey — October 31, 2012 — Leave a comment

Well folks, Movember is upon us. Some of you call this no-shave November and use it as an excuse to grow a beard or a goatee or something like that. It is officially called Movember and growing a sweet moustache is the proper way to raise awareness and money for men’s health issues. Prostate cancer research is a primary benefactor of the funds raised during Movember.

EWI is back fo’ Mo’ in 2012!

Last year, the 45 member team from EWI raised $2525 for men’s health issues. One member raised over $1000 all by himself! Last year there was a lot of excitement around Movember at EWI. We even had Monica Day from NBC4 visit us to kick off the event.

Check out the TV spot that originally aired on Channel 4 last year:

Watch this at WCMH

Maybe this year, once everybody is safe from Hurricane Sandy – aka Frankenstorm, we could get Jen Carfagno to stop by!

Our goal this year is to raise $4000 for research of men’s health issues.

If you would like to join our team, please visit this link: Join the Team to grow a ‘stache and help raise money for the cause.

If you would like to donate, please visit this link: Donate to the Team

Thanks for your support!

Ed Herderick Talks Silicon Carbide (SiC) Joining for Nuke Apps

Steve Massey — October 19, 2012 — 2 Comments

In this video published by The American Ceramic Society, Ed talks about the development and testing that EWI has been working on related to joining silicon carbide (SiC) ceramic matrix composites for use in nuclear reactors.

Please see the video posted on ceramics.org:

Video of Ed Herderick talking SiC joining

If you would like more information related to this topic, please contact Ed Herderick. You can reach him at 614.688.5000 or eherderick@ewi.org

You can also contact me (Steve Massey) at smassey@ewi.org. Please also see the other blogs introducing the members of the Materials team:

Ultrasonic soldering for medical and other electronic devices

Tim Frech — September 17, 2012 — Leave a comment

Ultrasonic soldering a variant of traditional iron soldering, where instead of requiring a flux to chemically reduce the metals’ surface oxides, the ultrasonic vibration from the soldering iron produces cavitation bubbles in the liquid solder. When the cavitation bubbles collapse, the mechanical motion of the collapse abrasively removes the surface oxides from the metal to be soldered. Once this occurs, the liquid solder can bond to the metal substrate. In both cases, the soldering iron tips are heated and keep the solder liquid or molten on the tip.

What happens to the surface oxide? Being an oxide, it is usually lighter than the liquid metal solder, and floats to the surface. This gives an ultrasonically-soldered joint more of a mottled or matte finish. However, the shear strengths of the joints are the same as a joint with the same alloy, soldered with flux.

Advantages of ultrasonic soldering include the cost savings in flux and post-solder flux removal operations, no fumes, and the ability to solder to difficult-to-wet metals. This last advantage provides design engineers with many more options for electronic components. Most metals need to be plated with nickel, tin, or both to provide a “solderable” surface. Metal plating is not a “green” process and is often a source of quality issues downstream in the manufacturing plant.

Ultrasonic soldering provides the ability to join most any metal to any other metal, such as a tungsten wire to a stainless steel leadframe, or a copper wire to a nickel tab. Joints will be limited in operating temperature based on the particular solder used. However, all solders can be used with ultrasonic soldering, including lead-free and zinc-based solders.

This is a photo of a 0.025” wide, 0.001” thick silver ribbon bonded to a polyimide-backed device. The ribbons were soldered to gold pads on the plastic substrate, without overheating the plastic. Additionally, due to the application, flux residue was not allowed. Therefore ultrasonic soldering with a tin-silver alloy was a great solution to join the leads to the device.

This article explained some benefits of ultrasonic soldering, along with a simple application example. For more information on how the process works, or how it might be applied to your difficult-to-solder materials, please contact me.

In Automotive, Consumer Goods, Energy, Resistance Processes, Soldering Brazing, Ultrasonic Processes microjoining, small-scale joining, soldering, ultrasonic

Adhesive Joining of Thermoplastics

George Ritter — September 11, 2012 — 2 Comments

Got a tough combination of molded components? Normally we weld, but sometimes the two materials are welding incompatible or the welding conditions are too extreme in temperature or time for the size of the part or complexity of the design. In that case, the option is to bond the materials.

Bonding thermoplastics is a little tricky because the surface energy is low compared with a thermoset material. It may be necessary to use a surface preparation technique to raise the wetting level. Dispensing can also be challenging, especially on small parts, but syringe units are quite sophisticated and give reproducible results. Once the components are joined, the curing can be fast if we used a cyanoacrylate or UV/VIS curable.

If you have a weird combination of materials to join, don’t be shy about asking us for suggestions. We work with all brands of adhesives and curing methods, and our goal is to get you running and successful. If you need testing or analysis, that’s no problem – we do that too. Bring it on, bring it over.

My name is Dr. George Ritter. I’m a materials engineer at EWI and I’ve been doing this for thirty years. Post your materials joining question below or contact me at gritter@ewi.org or 614.688.5199.

In Aerospace, Automotive, Consumer Goods, Government, Heavy Industry, Materials Engineering, Soldering Brazing adhesive bonding, adhesive joining, manufacturing, materials bonding, materials joining, thermoplastic bonding, thermoplastics

Making micro-scale wire welds

Tim Frech — September 10, 2012 — 2 Comments

When most people hear the word “welding” they think of the guy in the local garage with an arc welder and a mask, or the army of spot welding robots used to build a car body. You might be surprised to learn that there are many more welds in the sensors and motors in a typical car than are used to hold the body together. These include welds for the electric motors used for windows, door locks, and seat adjustments, as well as the sensors for engine emission, fuel level, and various lights and switches.

These welds are all “small-scale” welds, generally meaning the materials are less than a half millimeter in thickness, and are dissimilar welds; i.e. a copper wire to a nickel-plated brass terminal, or gold bonds to a microelectronic circuit.

In other electronics, like cell phones, laptops, and digital music players, much of the assembly of the electrical components is done with soldering. Soldering is a great technology for assembling circuit boards. The circuit board-to-battery, antenna, and other components are all soldered by hand or a specialized machine, but in today’s world, with ever-shrinking device sizes, the solder joint requires a major amount of “real estate” as there is a practical lower-limit to pad size. The main reasons for this are the limitations of robotic soldering equipment, ability for a person to reliably solder something less than 100 microns in size, and requirement of a solder fillet.

An option favored by many electronic device manufacturers is to weld the fine wires to assemble the device. Welding has many advantages over soldering: is it much faster (several welds per second vs. more than one second per solder joint), uses no consumables (no solder, no flux) and can be monitored for in-process quality control. Welding can be accomplished with resistance welding or ultrasonic metal welding.

In the past few months we have completed some projects to replace soldering in some electronic devices. The photo below shows a bridge wire for a pyrotechnic detonator.

The scale at the bottom of the photo is in mm. The wire spanning the two vertical legs is about 25 microns in diameter. This assembly is produced in the millions per year and is a single-use device. Soldering can be used to solder the wire, but the solder joint can bridge between the vertical legs, or more importantly, varying solder volumes affects the resistance of the wire. This, in turn, varies the “fusing current” and therefore can throw off the precise timing required for detonating the pyrotechnics. A resistance welding process was developed to precisely weld the wire at each end, producing a repeatable resistance in the joint. An additional, important benefit was the ability to monitor weld current, force, and electrode displacement for each weld. This provided in-process weld quality data and confidence that each and every weld was consistent.

Another application was the need of one of our clients to join a thin film of titanium to a platinum wire. This very specialized medical device application was very limited in the selection of materials, and the small pads needed to be produced at specific intervals along the wire’s length. Soldering was not an option as it would have added a non-biocompatible metal, and increased the overall size of the assembly. The titanium film was vapor-deposited on a glass slide, which was intended to be etched away later. Parallel-gap resistance welding was developed to resistance braze the platinum to the titanium film. A photo of the braze joints are shown here:

In the above photo, the silver wire runs left-to-right, and is 75 microns in diameter, and the titanium thin film is about 10 microns. Two braze joints are shown in this photo.

This article explained some benefits of welding over soldering for small-scale joining, using a couple of application examples. EWI has worked on a number of other applications, and would be pleased to discuss the potential of replacing your challenging soldering application with an appropriate welding solution.

In Consumer Goods, Energy, Resistance Processes, Soldering Brazing, Ultrasonic Processes microjoining, small-scale, wire bonding