There are many manufacturing methods and materials available to designers of metal components today. The processes each offer different benefits but are never without trade-offs. Similarly, different materials allow for a wide range of performance characteristics, but not without a certain cost.
As the Liquidmetal process and alloy continue gaining traction in a changing manufacturing marketplace, there is a growing need for comprehensive engineering information on the technology. Following its total update, thousands of copies of the Liquidmetal Design Guide 2.0 were read both online and in hard copy in recent months. The guide enabled engineers to identify candidate product applications for the technology as well as design new components for the process. The Liquidmetal Design Guide 3.0 will provide expanded information to customers on several topics including biocompatibility, corrosion resistance, magnetism, and more.
Welding is a joining process commonly used to build larger structures out of smaller components. Because amorphous metal formation requires specific critical cooling rates, the part size and thickness are somewhat limited. The ability to weld Liquidmetal® alloy to itself and to other dissimilar metals would extend the engineering applications of amorphous metals, helping to overcome the size limitation and offer more flexibility in part design and performance. Welds provide the strength, efficiency, versatility, and economic advantage necessary to build the myriad of structures and objects all around us – bridges, skyscrapers, automobiles, boats, oil rigs, the International Space Station, jewelry, sculptures (see Chicago’s Cloud Gate, a.k.a. “The Bean”), and more.
We are very pleased to present the results from our first round of ISO 10993 testing for our latest commercial alloy, LM105. ISO 10993 is a set of standards used for evaluating the biocompatibility of a medical device prior to clinical studies. Since several biomedical device companies have shown interest in Liquidmetal® alloys, we thought it would be beneficial to get a jumpstart on pre-screening the alloy for its potential use in biomedical applications. Of course, each biomedical device must undergo its own ISO certifications to account for its specific processing methods, but this set of tests serves to give potential customers confidence that LM105, our beryllium-free commercially available Zr-based amorphous metal alloy, is highly promising as a biomedical device material.
One of our most popular case studies compares various manufacturing methods for a missile component that controls flight. Supersonic missiles are highly sensitive to the exact geometry of control surfaces and precision is mission critical. Canards (French for “duck”) are the pivoting fins attached to the side body of missiles ahead of the main wing that provide stability and maneuverability for a projectile. Supersonic missiles must also shift between subsonic and supersonic speeds and canards affect the airflow against the main wing, altering the center of mass, and shifting the aerodynamic center. Thus, any deviation in geometric specifications will greatly affect flight control, causing extra turbulence and unanticipated movement.
A simple salt water immersion corrosion test was set up to get a general idea of the corrosion properties of Liquidmetal alloys. Here are the specimens we tested:
One of the prototypes that we have produced recently is moving closer to production. The prototype showcases the extraordinary elastic properties of Liquidmetal as a clamp. To protect customer confidentiality, we have disguised the geometry but are reporting actual results. We hope these will be of interest to other existing and potential customers.
In the first prototypes, two clamp spring designs were evaluated. A comparable steel solution would be expected to lose efficacy within 100 cycles, as the steel would yield and the clamp force would decrease. For this prototype design, a goal of at least 200 cycles without a decrease in the clamp force was specified. The clamp needed to be opened to create a gap close to the diameter of the circular clamp when closed (about 12mm).
Liquidmetal alloy has high resistance to corrosion for a number of reasons. Firstly, crystal defects, such as grain boundaries and dislocations, can act like galvanic cells to initiate localized corrosion – Liquidmetal does not have any such defects. Secondly, the elements we use in Liquidmetal form mechanically stable oxides which act as a passivating layer. Thirdly, the passivating layers form uniformly on the Liquidmetal surface, and so passivating elements are more effective than similar elements in a crystalline alloy.
Over the years, Liquidmetal Technologies have done various corrosion studies on our materials, and we are taking the chance to summarize some of the results here.
Size limit is perhaps one of the most commonly asked questions about the commercial fabrication of Liquidmetal alloys. “How big can we make it?” If you are familiar with typical commercially molded parts from Liquidmetal alloy you may have already observed a common theme; parts a few inches in any dimension and typically thin walled sections. The questions about size typically arise when engineers and designers become aware of the mechanical properties of Liquidmetal alloys: twice the strength of steel, high hardness, corrosion resistance, lustrous as-molded finishes, and high elasticity, among others. It’s not surprising that alloys with similar mechanical properties would be desired for high-performance structural applications such as aircraft bodies, I-beams, bridges, and car bodies. This post aims to help consumers understand the uses and clarify a few limitations of Liquidmetal alloys.
Michael Ashby, a professor from Cambridge, England, has developed strategy for the selection of particular materials for a specific application, a process called Materials Selection for Mechanical Design. In this method, all material properties are plotted against one another on axes displaying different mechanical properties (strength vs. toughness or cost vs. density, for example).
The difference in microstructure between Liquidmetal alloy and other materials may be the most underappreciated difference between Liquidmetal alloy components and products manufactured with other techniques such as metal injection molding (MIM) or additive manufacturing (AKA “3D Printing”).
If you have studied our website or have researched “bulk metallic glass”, you have likely seen an illustration of randomly distributed circles against a white background representing the liquid-like microstructure of Liquidmetal alloys. It is this random atomic structure that fundamentally enables the material properties and process advantages of our alloys. For more background and a history of bulk metallic glasses, please download our Liquidmetal whitepaper.
Many experienced product designers confuse Liquidmetal Injection Molding with MIM* (Metal Injection Molding). In an attempt to clarify the difference we have been crafting our message more carefully, and our new website is an attempt to do just that.
However, a picture is worth 1,000 words:
As Liquidmetal Technologies manufactures parts for new and exciting applications, Liquidmetal alloys continue to gain substantial attention from material scientists and physicists due to the unique properties and performance advantages of its amorphous molecular structure.
In the cover story in the February 2013 (Volume 66, Issue 2) print edition of Physics TodayIssue Cover, Liquidmetal Technologies’ class of materials (scientifically refered to as bulk metallic glasses) is featured in the article written by Dr. Jan Schroers, Professor of Mechanical Engineering & Materials Science at Yale.
In material science, deformation (described quantitatively as strain) occurs when a load (described quantitatively as stress) is applied to a material sufficient enough to cause the material to change shape. A temporary shape change that is completely reversible after the force is removed, so that the object returns to its original shape, is called elastic deformation.
When a load is sufficiently large enough to deform the metal irreversibly, so that the object does not return to its original shape after the load is removed, it is called plastic deformation. Plastic deformation involves the breaking of atomic bonds by the movement of dislocations which cause the material to yield. Dislocations are irregularities within a crystal structure which allow the atoms in crystal planes to slip past one another at low-stress levels.
While metallic glass has existed for decades, the majority of people became aware of its revolutionary properties when it was introduced as a product by Liquidmetal Technologies. Many people have seen our popular ”bouncing ball” demonstration on Youtube, where ball bearings dropped on plates of steel and titanium stop bouncing after a few seconds, while the ball on a plate of Liquidmetal seems to bounce well over a minute.
For designers who have traditionally expected dull, unattractive and pitted surfaces of traditional metal injection molded and die-cast parts, seeing the gorgeous as-cast surface of a Liquidmetal part comes as a shock. Liquidmetal parts have a shiny metallic luster straight from the mold without the need for time-consuming and costly secondary operations.
Liquidmetal alloy’s beautiful finish begins with using high purity alloy feedstock provided by one of the world’s leading metallurgical companies, Materion Brush. Liquidmetal Technologies then feeds that alloy into its own proprietary high purity vacuum injection molding platform.
There is a secret to designing an explosive device that penetrates heavy armor. More than a hundred years ago designers discovered a munitions device is more powerful when the explosive material is pressed into a concave shape on the open end of the casing, creating a cavity. When detonated, at just the right distance from the target, the force of a shaped charge can penetrate the thickest armor. When the cavity is covered by a copper or glass liner, the force from the explosive is much stronger. While in use for decades, the properties of this phenomenon were not fully understood. Pioneering work from the world-renowned Lawrence Livermore National Laboratory now allows the properties of the supersonic jet that escapes from lined shaped charges upon detonation to be accurately modeled. Detonation forces the liner to collapse inwardly with tremendous force, projecting a tightly focused jet of liner material with enormous energy.
Mirrors are used every day by nearly everyone. A reasonably accurate, inexpensive mirror can be made by simply silvering a plate of glass. Deliberate distortions can be made by forming the glass into shapes, such as fun-house mirrors that can make you appear shorter, taller, stout or slender.
You may have been reading about recent developments in metals technology from a diverse range of sources. Many of the exotic metal alloys being described are actually the same material being referred to by different names. For example, Liquidmetal Alloys, amorphous metal and metallic glass are basically synonyms for the same new class of metals which exhibit a non-crystalline atomic structure.