19.09.2022

Common Low Melting Alloys and Their Characteristics


There is a wide range of low melting alloys available. Yet some are restricted in their use based on their brittleness, toxicity, and reactive qualities. Some of these elements are bismuth, gallium, tin, indium, zinc, cadmium, tellurium, antimony, thallium, mercury, and lead. Many of these minerals may also be additives placed during the formation of the low melting alloys. ;






Density Characteristics


One of the main reasons for using low melting alloys is due to how it changes when it melts and then solidify. Some alloys are eutectic and will become pure liquid instantly, while others are Non-Eutectic and will transition through a semi-liquid state that has a type of slushy texture before becoming liquids. Low melting alloys will also change in density when solidifying. Alloys such as bismuth and gallium will expand greatly when in their liquid state and then become dense when changing back into a solid.


Knowing the density of the alloy is important as the manufacturer needs to know how much it will shrink or expand. If the metal shrinks too much, it may not create the proper bond with other materials, or have the required strength it needs to withstand stresses. If it expands too much, it can become brittle when changing back into a solid as the alloy might fail during the operation of the product or equipment.


The varying densities of the alloys can also be important to manufacturers based on how they plan to use the alloy. For delicate jewelry, you may not want a material to expand too much as it could end up damaging the surrounding metal that needs to remain intact. You also need to pay attention to the elongation, strength, tensile modulus, and yield strength of the alloy during the manufacturing process.






Bismuth Alloys



Bismuth-based: Bismuth alloys will have a composition that is less of a ductile characteristic than tin, as it can become brittle. Manufacturers use bismuth due to its expansion qualities when it melts and then solidifies as it can expand to up to 3.3%. The more bismuth is in an alloy, the more it expands. It is less expensive than other alloys that are featured and the least toxic as it can be used in applications where there is drinking water present. ;


Bismuth compounds account for about half the production of bismuth. They are used in cosmetics; pigments; and a few pharmaceuticals, notably bismuth subsalicylate, used to treat diarrhea. Bismuth's unusual propensity to expand as it solidifies is responsible for some of its uses, such as in the casting of printing type. Bismuth has unusually low toxicity for heavy metals. As the toxicity of lead has become more apparent in recent years, there is increasing use of bismuth alloys (presently about a third of bismuth production) as a replacement for lead.






5 Types Of Indium Alloys You May Want To Know


A Brief Introduction To The Indium Alloy


Indium alloy is generally divided into binary alloys, ternary alloys, and multi-component alloys.


Generally, the melting temperature of indium alloy mainly composed of indium is relatively low, which is mainly used as some low melting point alloys or solders.


While some alloys have very little indium content, indium mainly plays a role in modification, such as improving the strength of non-ferrous metal alloys, improving their ductility, abrasion resistance, corrosion resistance, and changing the color of precious metals.






Classification Of The Indium Alloy


Generally, the indium alloy can be divided into 5 categories, which are bearing alloys, ferromagnetic alloys, memory alloys, decorative alloys, and dental and gemstone alloys. The following is a brief introduction to the 5 types of indium alloy:


1. Bearing Alloy


Bearing alloys are widely used in the aviation and automotive industries. The bearing alloys mainly used in the manufacture of high-speed engine bearings include silver-lead-indium alloy, lead-cadmium-indium alloy, cadmium silver-copper-indium, silver-thallium-indium alloy, lead-tin-indium alloy, copper-tin Indium alloy, lead tin antimony arsenic indium alloy.


2. Ferromagnetic Alloy


Ferromagnetic alloys are also called Heusler alloys. The most widely used ferromagnetic alloy is copper manganese indium alloy (Cu / Mn / In).


3. Memory Alloy


Indium thallium alloy (In / Tl) and indium cadmium alloy (In / Cd) are memory alloys, which belong to the new generation of alloys.


4. Decorative Alloy


The addition of indium to the gold-silver-palladium-copper alloy used for ornaments can improve the hardness and durability of the ornaments and increase their color of the ornaments. The commonly used Au75 / Ag20 / In5 alloy is commonly known as “green gold”.


5. Dental And Gemstone Alloy


Indium alloy is also used in dentistry and gemstones. Its composition is usually: gold 5 to 65% / palladium 2 to 30% / silver 10 to 15% / copper 10 to 15% / indium 0.5 to 5%.






Lead-tin


Lead-tin alloys containing up to 98 percent by weight in are used as soldiers. The strengths of these alloys increase with higher tin content, while the melting point is lowered to a minimum of 183 °C (361 °F) with a lead content of 38 percent. A half-lead–half-tin alloy is the most common general-purpose solder. Considerably lower tin contents, from around 5 to 30 percent, are used by the automotive industry for soldering radiator cores and for other applications. Tin contents as low as 2 percent are used in the canning industry. The electronics industry requires low-melting solders to protect heat-sensitive components, and so tin contents generally are around 60 to 65 percent.






Fusible Alloy Preforms


Fusible alloys are stable and can either be classified as eutectic or non-eutectic. Eutectic alloys have the lowest melting point possible—the temperature at which the material is solid is equal to the temperature at which the material is liquid. Non-eutectic alloys begin to melt at one temperature and then enter a slushy state before they fully melt at a higher temperature. Low-melting alloys are available in a variety of forms: cake, ingot, bar, shot, wire, stick, strip, and custom shapes.


Many of the low-melting alloys have good thermal conductivity, can be remelted and reused, and have combinations of elements that cause them to expand during solidification without contracting during cooling. These characteristics make fusible alloys versatile, allowing them to be used in a diverse amount of applications, including common everyday items such as fire sprinklers and pop-up turkey timers. In both cases, the alloys begin to melt at a specific temperature, triggering a mechanism that either opens a valve to let water flow or pops up a button to indicate the turkey is done.


Manufacturers can use fusible alloys to solve problems and save time and money. For instance, using a fusible alloy when bending thin-walled tubing can help prevent kinks or wrinkles. Tubes are lubricated, filled with a low-melting alloy, and cooled so that the alloy solidifies inside, supporting the tube’s wall. Once bent, the tube is reheated to liquefy and remove the fusible alloy.


Along similar lines, fusible alloy preforms can be used for manufacturing complex aerospace components that have internal cavities or as cores for forming fiberglass laminate or plastic parts. Fusible alloys also can be used to hold delicate or irregular-shaped workpieces, such as optical components, during manufacturing operations. After the component is polished or machined, the alloy is melted off and reused. Some fusible alloys are capable of sealing glass to glass or glass to ceramic in electronic devices, vacuum systems, and laboratory equipment. They can even be used as master alloys to add lead, bismuth, or tin to aluminum and other metals.






Precision Die Casting Parts and Assemblies


Why Precision Die Casting?


Precision Die Casting is the manufacturing process that pours or injects molten metals into molds made from steel, compressed sand, and other materials. This allows each part to be created with accuracy and repeatability.


Die Casting Material


Alloys that are suitable for die casting are those that are corrosion resistant and have optimal density. Our engineers assess the mechanical properties such as strength, hardness, and elongation when picking the right alloy to use for your die-cast. ;


The most common Precision Die Casting Parts are aluminum, magnesium, zinc, and copper. ;


Aluminum Die Casting


Aluminum alloys are our most common material for die cast parts. ; Aluminum die-cast parts have a lot of advantages which allows us to create parts with high dimensional stability with complex part geometries and in a very efficient way.


Zinc Die Casting


Zinc alloys are a strong, durable, and cost-effective material. They provide a very good combination of strength, toughness, rigidity, and cast-ability with superior finishing capabilities.

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