Semisolid Casting Apparatus for Microstructure Control
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Solution Overview
Problem
Current semisolid casting and forging techniques face challenges in achieving high yield rates for thin products without complex process steps or equipment, particularly in controlling the microstructure and reducing raw material usage, while maintaining mechanical properties.
Innovation Solution
A semisolid melt forging apparatus and method where a metal melt is teemed into a lower die, and the dies are moved relative to each other at controlled rates and distances to form a semisolid slurry with microfine crystal grains, allowing for rapid molding and reduced raw material usage, with adjustable temperature control and die settings to optimize product properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional rheocasting or thixocasting methods are used, then semisolid casting can be achieved, but equipment complexity and cost increase
Solution Approach 1:
The invention extracts the slurry formation process from the die cavity, performing crystallization in a separate pouring basin before injection. This eliminates the need for complex in-die cooling systems and electromagnetic agitation equipment, achieving semisolid casting with simple injection molding equipment
Solution Approach 2:
The metal melt is preliminarily solidified to form a semisolid slurry with microfine spherical crystals in the pouring basin before being injected into the die cavity. This preliminary action creates the desired microstructure in advance, eliminating the need for complex in-process control during molding
2Productivity
If thixocasting method is used to form semi-metal slurry, then casting can be performed, but energy consumption increases due to re-melting
Solution Approach 1:
The invention changes the thermal parameters by using a pouring basin temperature lower than the metal melt temperature, controlling the solidification process to form semisolid slurry without complete re-melting. This parameter control achieves energy efficiency while maintaining productivity
3Manufacturing precision
If conventional NRC process is used, then semisolidified slurry can be formed, but production time increases
Solution Approach 1:
The invention utilizes controlled phase transition from liquid to semisolid state in the pouring basin, where metal melt rapidly solidifies to form a slurry with microfine spherical crystals. This phase transition occurs quickly due to the temperature difference, reducing production time while maintaining microstructure quality
4Weight of moving object
If conventional rheocasting is used, then light-weighting can be achieved, but material recycling capability is lost
Solution Approach 1:
The invention enables the casting system to serve itself by allowing excess or defective parts to be easily re-melted and reused in the same pouring basin system. The simple equipment design facilitates material recycling without requiring separate processing lines, maintaining both light-weighting and recyclability
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables the production of products with superior mechanical properties and reduced raw material consumption, capable of achieving thin and thick sections without intricate equipment, ensuring high yield and reproducibility.
Implementation Method 1
a metal melt or molten metal is teemed or poured into a cavity in a lower die... to form a semisolid slurry
Implementation Method 2
moving an upper die closer to the lower die allows the massive mixture in the semisolid state to be compressed and deformed
Data Source
AI summary
An excellent cast and forged product that is superior in mechanical properties and has a microstructure and which may not only be a thin but also be a thick product can be made without using complicated process steps or equipment. A semisolid casting and forging method is provided in which a metal melt is teemed so that it is supercooled into a lower die in a press so controlled that the metal melt has a rate of solidification as desired, thereby preparing a semisolid slurry; an upper die is brought into contact with the semisolid slurry; and thereafter at least one of the upper and lower dies is moved relatively towards the other at a rate of movement between 0.1 and 1.5 m/sec, thereby compressing the semisolid slurry to mold it into a product. The semisolid slurry preferably has crystal grains of a grain size of 50 μm or less.