Molybdenum crucible: The core evaporation source in the precise coating process
In the modern high-tech industry, physical vapor deposition technology is a key process for fabricating various functional films. It is like a "brush" in the microscopic world, depositing materials layer by layer and atomically on the substrate, thereby endowing products with specific optical, electrical or protective properties. In this precise "painting" process, the molybdenum crucible plays an indispensable role - it is precisely the "heating brush" that precisely controls, carries and evaporates the coating materials, namely the evaporation molybdenum boat or evaporation source.
Why choose molybdenum crucibles? An analysis of their outstanding performance
Not all materials can fulfill the role of an evaporation source. This role requires stability, reliability and efficiency under extreme conditions. Molybdenum crucibles, with their unique physical and chemical properties, perfectly meet all these demanding requirements:
Extremely high melting point and thermal strength
The melting point of molybdenum is as high as 2622°C. During the PVD process, the coating materials such as aluminum, gold, silver, and copper need to be heated to their vaporization points (usually above 1000°C). Even at such high temperatures, the molybdenum crucible can maintain its structural strength and shape, without softening, deforming or melting, ensuring the stability and repeatability of the process.
Excellent thermal conductivity and resistance properties
As a resistance heating type evaporation source, the molybdenum crucible generates high temperature rapidly by directly passing through a large current. Its excellent electrical conductivity and thermal conductivity enable the heat to be evenly and rapidly transferred to the entire crucible and the internal coating material, achieving efficient and uniform evaporation.
Outstanding thermal shock resistance and structural stability
During the coating process, the molybdenum crucible needs to undergo repeated cycles from room temperature to over 1000 degrees Celsius and then cooling back to room temperature. Its low thermal expansion coefficient and excellent toughness enable it to withstand such intense temperature fluctuations without cracking, ensuring a long service life.
Various forms of design to meet different needs
In practical applications, molybdenum crucibles, as evaporation sources, have multiple flexible design forms:
Open-ended crucible: The simplest form, it directly holds metal blocks or wire materials, and is suitable for situations where the evaporation rate requirement is not extremely high.
Covered crucible / Limiting crucible: The top is equipped with small holes, which can effectively control the direction of metal vapor ejection, reduce splashing, improve material utilization and film uniformity. It is particularly suitable for evaporating granular or powdered materials.
Multi-layer silk-coated crucible: Sometimes, molybdenum sheets or molybdenum wires are directly processed into spiral or boat-shaped heaters. The material to be evaporated (such as aluminum wire) is directly placed inside to achieve continuous evaporation.
Despite its outstanding performance, the molybdenum crucible evaporation source has one strict prohibition that must be strictly followed: absolutely avoid working at high temperatures in an oxygen-containing atmosphere. Molybdenum will rapidly oxidize in the air at temperatures above 400°C, generating volatile molybdenum trioxide, which causes the crucible to rapidly deteriorate and fail. Therefore, all evaporation processes must be carried out in a high vacuum environment (usually below 10-2 Pa).
On the stage of nano-scale precision coating, the molybdenum crucible might seem like an insignificant component, but it is the cornerstone of the entire process. With its resilient "heat-resistant body" and stable "chemical barrier", it ensures the controllable, pure and efficient evaporation process. From the chips in our mobile phones to the anti-reflection coatings on glasses, from the dazzling decorative coatings to the efficient solar cells, behind these high-tech products, there is the silent contribution made by the molybdenum crucible as the evaporation source. It undoubtedly is an indispensable "behind-the-scenes hero" in the modern materials surface engineering field.
The molybdenum crucible is in high demand in various parts of the world, such as: USA, Canada, Chile, Brazil, Argentina, Colombia, Germany, France, United Kingdom, Italy, Sweden, Austria, Netherlands, Belgium, Switzerland, Spain, Czech Republic, Poland.
Mosten Alloy can produce molybdenum crucible for crystal growth, molybdenum tube, molybdenum sheet, molybdenum pellet, molybdenum block, molybdenum foil, molybdenum rod, molybdenum wire, molybdenum processing workpiece according to customer demand.
