Toy Hinge Titanium Alloy Lost-wax Casting

1. Mold Design and Manufacturing: Based on the toy spinner design drawings, precise modeling is performed using Computer-Aided Design (CAD) software. Then, CNC machining and other technologies are used to manufacture the mold used to press the wax model. The precision of the mold directly affects the quality of the wax model; therefore, manufacturing tolerances must be strictly controlled.

2. Wax Selection and Melting: A suitable wax is selected, commonly a medium-temperature wax composed of paraffin wax, stearic acid, etc. The wax is heated to an appropriate temperature to completely melt, with constant stirring during the melting process to ensure uniformity and absence of air bubbles.

3. Wax Pattern Pressing: Molten wax is poured into the mold under pressure to fill the mold cavity. After the wax cools and solidifies, the mold is opened and the wax pattern is removed. The wax pattern is inspected, and defects such as flash and burrs are removed.

4. Wax Pattern Assembly: To improve casting efficiency, multiple wax patterns are usually combined into a wax pattern assembly. Individual wax patterns are fixed to the sprue bar by welding or bonding to form a complete gating system.

1. Coating: The wax pattern assembly is immersed in a coating composed of refractory materials (such as silica sol, zircon powder, etc.) and a binder, so that the surface of the wax pattern is evenly covered with a layer of coating. The viscosity and thickness of the coating will affect the quality of the mold shell and need to be adjusted according to specific process requirements.

2. Sand Sprinkling: After coating, the wax pattern assembly is immediately placed in sand, allowing the sand to adhere to the coating surface. The particle size of the sand is selected according to the number of mold shell layers and casting requirements, generally starting with coarse sand and progressing to fine sand in multiple applications.

3. Drying and Hardening: After coating and sanding, the wax mold assembly needs to undergo drying and hardening treatment to allow the shell to gradually solidify. The drying process is usually carried out in a specific environment, controlling temperature, humidity, and ventilation conditions to ensure stable shell quality. Repeat the coating, sanding, drying, and hardening steps until the shell reaches the required thickness.

4. Dewaxing: Place the prepared shell into a dewaxing device, where the wax model is melted and flows out using steam, hot water, or other methods. The dewaxing process must ensure complete removal of wax to prevent residual wax from affecting the casting quality. After dewaxing, the shell is cleaned and inspected to remove residual wax and impurities.

1. Titanium Alloy Smelting: Select suitable titanium alloy raw materials and precisely batch them according to alloy composition requirements. Place the raw materials in a vacuum induction furnace for melting. The vacuum environment prevents the titanium alloy from reacting with oxygen, nitrogen, and other elements in the air, ensuring alloy quality. Strict temperature and time control is required during the melting process to ensure uniform alloy composition.

2. Pouring: Once the titanium alloy has been melted to a suitable temperature and achieved the desired fluidity, it is rapidly poured into a preheated mold. The pouring process should be smooth and rapid to avoid defects such as porosity and inclusions. Pouring temperature and speed have a significant impact on casting quality and need to be adjusted according to the size, shape, and complexity of the casting.

1. Mold Removal: After the casting has cooled, the mold shell is removed using methods such as mechanical vibration or sandblasting. Care should be taken to avoid damaging the casting surface during shell removal.

2. Gate Removal: The casting is separated from the sprue using cutting equipment. After removing the sprue, the cut is ground and finished to ensure a smooth surface.

3. Heat Treatment: The casting is heat-treated to improve its mechanical properties. Common heat treatment processes include annealing, quenching, and tempering. The appropriate heat treatment process is selected based on the composition of the titanium alloy and the application requirements.

4. Surface Treatment: To improve the corrosion resistance and aesthetics of the toy's hinge, surface treatment can be performed. Common surface treatment methods include electroplating, spraying, and passivation.

1. High Precision: Lost-wax casting can produce toy shafts with high dimensional accuracy and good surface quality, meeting the high precision requirements of toy design.

2. Complex Shape Forming: It can manufacture toy shafts with complex shapes, providing more possibilities for toy design.

3. Excellent Material Properties: Titanium alloys possess superior mechanical properties and corrosion resistance, making toy hinges more durable.

1. High Cost: Lost-wax casting is a complex process involving multiple stages and specialized equipment, resulting in relatively high raw material and manufacturing costs.

2. Long Production Cycle: From wax model making to finished casting, multiple processes are required, leading to a long production cycle and hindering rapid response to market demands.

3. High Technical Requirements: Lost-wax casting demands high levels of process technology and operator skill, requiring extensive experience and professional knowledge.