Description:FIELD OF THE INVENTION
This invention is for a device that holds a graphite stirrer and improves the mechanical stirring of molten metal during stir casting. The device is designed to fit different sizes of stirrers and can be adjusted to prevent the coagulation of reinforced particles in melt-based composites.
OBJECTIVES OF THE INVENTION
The prime objective that is aimed to be achieved through this invention is that the stirrer holder should accommodate a range of stirrer diameters to ensure effective swirling of molten metal and it should also operate efficiently, be mechanically driven, and require minimal maintenance.
BACKGROUND OF THE INVENTION
Mechanical stirrers are used to agitate molten metal in a crucible, creating a swirling effect that helps to break down dendritic structures and evenly distribute reinforced particles. The primary function of the stirrer is to ensure thorough mixing of the molten metal matrix and the reinforcement materials (such as ceramic particles, fibers, agricultural and industrial wastes or other materials) to create a homogeneous mixture. This mixing is essential to achieve uniform distribution of the reinforcement within the matrix. The stirrer helps disperse the reinforcement materials evenly throughout the molten metal, preventing clustering or agglomeration of the reinforcement particles. This uniform dispersion contributes to the mechanical properties and overall performance of the resulting composite. It aids in maintaining a consistent temperature throughout the mixture. Homogeneous heating and mixing are critical to prevent localized overheating or cooling, which can affect the properties of the final composite material. Also, by controlling the speed and movement of the stirrer, manufacturers can influence the microstructure and properties of the composite. Optimal stirring conditions, such as rotational speed and direction, contribute to achieving desired mechanical and structural properties in the composite.
The stirrer produces swirling motion in the molten metal during motion. The swirling motion is a crucial aspect of the stirring process in stir casting. It ensures that the molten metal and reinforcement materials are thoroughly mixed and uniformly dispersed, leading to the creation of high-quality metal matrix composites with enhanced mechanical properties and performance characteristics. However, variations in the swirling motion of the molten metal from the center to the outer edges can lead to uneven dispersion of the reinforced particles, which can pose challenges during composite fabrication. The present invention addresses this issue by employing a flexible stirrer holder that allows for adjustments in stirrer diameter. While mechanical stirrers have been developed in the past, none have specifically addressed this problem. U.S. Patent No. 3,902,544, issued to Flemings et al., describes a mechanical stirring process for agitating molten metal before pouring to produce non-dendritic primary solids. U.S. Patent No. 4,373,950,538, issued to Shingu et al., discloses the use of mechanical stirring to break down dendrites that extend from the liquid-solid interface into the liquid phase.
Based on the aforementioned challenges, this research aimed to design a stirrer holder that enables the simple attachment of a graphite stirrer without the need for internal threading, gluing, clips, or bolts.
Summary of the Invention
The objectives outlined above have been successfully achieved through this invention. The investigation has resulted in the development of a stirrer holder that can accommodate graphite stirrers of various diameters, enabling the generation of sufficient vortex for uniform dispersion of reinforcements in molten metal during stir casting for metal matrix composites fabrication. The holder's easily interchangeable design allows for integration of graphite stirrers with a variety of profiles and diameters to meet specific user requirements. Moreover, its low energy consumption and effective design make it ideal for fragmentation of fine-grained castings and reinforced particles.
Brief description of drawings
The invention will be described in detail with reference to the exemplary embodiments shown in the figures wherein:
Figure 1: A 3D pictorial representation of stirrer holder according to an embodiment of the present invention;
Figure 2: An exploded view of embodiment parts
Figure 3: An isometric view of the holding device with an installed graphite stirrer
Detailed description
The holder for a stirrer in stir casting is an essential component within the casting apparatus, playing a pivotal role in the intricate process of fabricating metal matrix composites. Designed to secure and support the stirrer, this holder is crucial for ensuring stability, alignment, and effective functionality during the mixing phase. Stability stands as a paramount requirement for the holder, as it directly influences the overall performance of the stirring process. By providing steadfast support to the stirrer, the holder mitigates excessive vibrations or erratic movements, thereby ensuring a consistent and reliable mixing environment. This stability is pivotal in guaranteeing the uniform distribution of reinforcement materials within the molten metal, a fundamental aspect contributing to the quality and integrity of the resultant composite material. Alignment precision is another key attribute of the stirrer holder. Proper alignment of the stirrer within the holder framework is imperative for achieving an even dispersion of the reinforcement materials throughout the molten metal matrix. Any misalignment can compromise the uniformity of the mixing process, potentially leading to irregular distribution or clustering of reinforcement particles. Therefore, the holder's design emphasizes the importance of aligning the stirrer accurately, facilitating the creation of a homogeneous mixture that enhances the mechanical and structural properties of the resulting composite. Versatility and adjustability also find their place within the realm of stirrer holders. Some holders are engineered with features allowing adjustments in the position or angle of the stirrer. This adaptability empowers manufacturers to optimize the stirring process, accommodating diverse materials or adapting to varying production conditions. The ability to modify the orientation or placement of the stirrer within the holder provides a level of flexibility, enabling the customization of the mixing process for different composite materials and ensuring consistent quality across various production runs. Compatibility remains a cornerstone consideration in stirrer holder design. The holder must seamlessly integrate with the specific stirrer being utilized, considering factors such as size, shape, and attachment mechanisms. This compatibility ensures a snug and secure fit, optimizing the stirrer's functionality within the holder structure. A harmonious compatibility between the holder and stirrer guarantees an efficient and effective stirring process, fostering the uniform dispersion of reinforcement materials and the creation of high-quality metal matrix composites
Refereeing to Fig. 3, the stirrer holder is used for holding a graphite stirrer in accordance with a preferred embodiment of the invention. The holder is composed of a hollow metallic pipe 1. The fastening assembly 2 is mounted inside the hollow pipe 1. One end of assembly 2 is mounted on a spacer 3 and other end is attached accordance with Fig. 1. The fastening assembly 2 comprises a trapezoidal-shaped nut 2, 3 and a hexagonal nut 2, 2 which are rotated on a threaded bar 2, 1 (both ends are threaded in opposite side). Hexagonal nut 2, 2 is rested on spacer 3 to the distal end of the pipe 1. In each rotation of the hexagonal nut 2, 2, the trapezoidal-shaped nut 2, 3 moves upwards. The upward motion of the trapezoidal-shaped nut 2, 3 expands slotted section of the hollow pipe 1 (refer to fig. 1). As a result, assembly tightly holds the graphite stirrer without any threaded section, glue or clips. The attached graphite stirrer with the assembly is shown in fig. 3. , Claims:The scope of the invention is defined by following claims:
Claim
The scope of the invention is defined by following claims:
1. A stirrer holding device comprising:
a. A specially designed one end slotted hollow pipe 1.
b. A fastening assembly which includes a both end threaded bar 2, 1, a trapezoidal-shaped nut 2,3 and a hexagonal nut 2,2.
c. The fastening assembly 2 is placed inside the hollow pipe 1, according to the figure 1.
d. The outwards and inwards expansion of the slotted section of the hollow pipe 1 is responsible for the tightening and releasing of the graphite stirrer (refer to fig. 3).
2. The stirrer holder of claim 1, comprising one end slotted hollow pipe 1.
3. The stirrer holder of claim 2, wherein the fastening assembly unit comprises: a both ends threaded bar. One end comprises a hexagonal nut 2, 2 and the other end is specially designed trapezoidal shaped nut.
4. The stirrer holder of claim 3, wherein fastening assembly further comprising the end which rests on the spacer 2 and the other end is freely attached with the hollow pipe 1 according to arrangement shown in fig. 1.