Liquid metal filling process is the first stage of casting formation in which many defects of the casting are formed.This process must be mastered and controlled in order to obtain high quality sound castings.To this end, the ability of liquid metal to fill the mold is studied in order to obtain a fully formed, well-defined casting to prevent defects in the mold filling phase.The ability of a liquid alloy to fill the mold cavity to form a well-defined, well-formed, high-quality casting is called the fluidity of the liquid alloy and the filling capacity.The better the fluidity of the liquid alloy, the easier it is to cast clear, thin and complicated shapes, and the more the liquid alloy can be supplemented when it contracts in the mold, the more the gas and non-metallic inclusions in the liquid alloy can float up and get rid of.If the fluidity is not good, it is easy to cause casting to produce defects such as under casting, cold isolation, porosity, slag inclusion and shrinkage.Liquid metal filling casting is a complex physical, chemical and hydrodynamic problem, which involves various properties of liquid metal, such as density, viscosity, surface tension, oxidization, oxide properties and wettability.The size of filling capacity affects the forming of casting, and the alloy with poor filling capacity is difficult to obtain large, thin - walled, sound casting with complex structure. The factors that affect mold filling function through two ways: one is to influence the heat exchange condition between the metal and the mold, thus changing the flow time of the liquid metal; The other is to influence the hydraulic conditions of the liquid metal in the casting, so as to change the flow rate of the liquid metal.
What is a liquid metal thermal paste?Liquid metal thermal paste is a paste-like material with metallic characteristics.It has the following characteristics:1.High thermal conductivity2. Good adhesion3. High temperature resistance4. Does not flow at high temperatures5. Non-volatile6. Does not oxidize7. Does not cure at room temperature8. Conductive9. Non-flammable and explosive10. Non-toxic environmental protectionApplication fields of liquid metal thermal paste.Liquid metal thermal pastes can be used in magical aerospace and Computer configuration, and much more. This is a novel in recent years, and its thermal conductivity is far superior to traditional silicone oil-based silicone grease.The method of use is to first clean the surface of the object, take out a small amount of liquid metal thermal paste, and apply it evenly on the surface.It is also a pure metal paste-like thermal interface material, which has super high thermal conductivity and stability, can break through the traditional thermal interface materials, and has excellent thermal conductivity. Widely used for heat dissipation of electronic equipment in high temperature and high density heat flow occasions.How often to replace theliquid metal thermal paste?After testing, the performance of the liquid metal thermal paste used on the CPU for more than 2 years has not deterioratedIt can be seen that the liquid metal thermal paste has a long service life.NOTICE: Liquid metal is conductive, novices need to do a good job to insulation, and don’t put liquid metal with aluminum and aluminum alloyLiquid metal thermal paste and thermally conductive silicone greaseSilicone grease filling effectFor safety considerations, the conductivity of silicone grease must be very weak. Therefore, some silver and aluminum will be added on the basis of aluminium oxide to improve the thermal conductivity. Due to the smallest particles still can’t fill the gap completely, the effect of silicone grease is very limited.Advantages of liquid metals Even if the traditional silicone grease doesn’t care about the conductivity, full use of metal powder is useless. The cost of moving from micron to nanometre will increase exponentially, but the performance will be not very strong.Metals are directly composed of atoms, and the atoms are connected by metal bonds. Since the outer layer of the gallium atom has only three electrons, the force of constraining between the atoms is very weak, so the gallium-based alloy can be in a liquid state at normal temperature.Liquid metalfilling effectNanometrethermalpasteThe performance of liquid metal is modified by a special process. The metal thermalpaste made by adding nanometre metal particles is a 100% thick metal thermal grease with a thermal conductivity that more than 20 W / m · K, it’s veryadhesive and heatresisting. It will not flow, evaporate, oxidize or dry out in high temperature environments. It is an ideal thermally conductive material to replace silicone grease. It can also be used for IGBT and large LED cooling, power battery cooling, CPU / GPU cooling, and can maintain high thermal conductivity and safety for a long time. Metal thermal paste is a non-toxic product that complies with EU RoHS standards. It can be directly applied between the heat source and the heat sink, which can completely fill the gap and take advantage of the high thermal conductivity of the metal. The applied thickness can be between 0.01 mm and 0.2 mm. At the same time, the liquid metal does not react with copper and stainless steel, so that the safety and service life of the contact device can be achieved. ingredientGaInSnAgZnThermal conductivity>20W/m·KPackaging specifications5g, 10g, 100gConductivity3 X 106S/mViscosity8000 mPa·sOperating temperature-50℃～600℃Volatility