Lock Cylinder Rotor Titanium Alloy Lost-wax Casting

o High Strength: Titanium alloys have strength similar to alloy steel, but a much lower density, allowing for weight reduction while maintaining sufficient strength in the lock cylinder rotor. This is significant for specialized locks with weight constraints, such as those used in aviation.

o Corrosion Resistance: A dense oxide film forms on the surface of titanium alloys. This oxide film has excellent chemical stability, effectively resisting corrosion from various media, including humid air and seawater. This means that lock cylinder rotors made of titanium alloys can be used for extended periods in harsh environments without corrosion, extending the lock's lifespan.

o Biocompatibility: While biocompatibility is not a critical factor in ordinary locks, in some special applications, such as locks for medical devices, the biocompatibility of titanium alloys can prevent adverse effects on the human body.

o Composition Selection: Based on the specific usage requirements and performance indicators of the lock cylinder rotor, a suitable titanium alloy composition is selected. Common titanium alloys include Ti-6Al-4V, where aluminum (Al) improves the strength and thermal stability of the titanium alloy, while vanadium (V) helps improve the alloy's machinability and toughness.

* Mold Design: Based on the three-dimensional model of the lock cylinder rotor, a mold for making the wax model is designed and manufactured. The precision of the mold directly affects the dimensional accuracy of the wax model; therefore, high-precision machining equipment and processes are required to manufacture the mold.

* Wax Model Forming: Molten wax is injected into the mold. After the wax cools and solidifies, the wax model is removed from the mold. To ensure the quality of the wax model, process parameters such as wax temperature, injection pressure, and cooling rate need to be controlled.

* Wax Model Assembly: Individual wax models are assembled into a wax model assembly by welding or bonding to facilitate subsequent casting operations. During assembly, it is crucial to ensure secure connections and accurate positioning between the wax models.

* Applying Slurry: The wax model assembly is immersed in a slurry composed of refractory materials, binders, and additives, ensuring a uniform coating of slurry on the surface. A layer of refractory sand is then sprinkled onto the slurry surface to ensure firm adhesion.

* Drying and Hardening: The wax model assembly coated with slurry and refractory sand undergoes drying and hardening treatment. This allows the binder in the slurry to react chemically, forming a robust shell. The drying and hardening time and temperature parameters need to be carefully controlled based on the slurry composition and environmental conditions.

* Repeated Coating: To ensure the strength and thickness of the shell, the slurry and sand coating process is repeated, typically requiring 3-5 layers. Each layer must be dried and hardened after application.

* Dewaxing: The prepared mold shell is placed in a dewaxing device. Heating melts the wax model, causing it to flow out of the mold shell, thus forming a cavity inside the mold shell that matches the shape of the lock core rotor. During dewaxing, the heating temperature and time must be carefully controlled to prevent the mold shell from cracking.

* Titanium Alloy Melting: The titanium alloy raw material is placed in a vacuum induction furnace for melting. During melting, parameters such as vacuum level, temperature, and melting time must be strictly controlled to ensure the uniformity and purity of the titanium alloy composition.

* Casting: Once the titanium alloy has reached the predetermined temperature and composition requirements, it is quickly poured into the preheated mold shell. During casting, attention must be paid to the pouring speed and method to avoid defects such as porosity and inclusions.

* Mold Shell Cleaning: After the casting has cooled, the mold shell is removed using methods such as mechanical vibration and sandblasting.

* Heat Treatment: The lock core rotor undergoes heat treatment to improve its microstructure and properties. Common heat treatment processes include annealing, quenching, and tempering. Specific heat treatment parameters need to be determined based on the titanium alloy composition and the application requirements of the lock cylinder rotor.

* Machining and Surface Treatment: According to the design requirements of the lock cylinder rotor, it is machined, such as through drilling and milling, to achieve precise dimensions and surface roughness. Finally, the lock cylinder rotor undergoes surface treatment, such as electroplating and spraying, to improve its wear resistance and corrosion resistance.