Cutting Insert Powder Pressing for Uniform Green Compact Density
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Solution Overview
Problem
Cutting inserts with uneven upper and lower surfaces and varying thicknesses experience density dispersion during the powder molding process, leading to strain and deformation upon sintering.
Innovation Solution
A method involving a preliminary molding step where the upper punch with a distinct surface shape is used to fill the thick portions of the green compact with more raw material powder than the thin portions, ensuring uniform density before final molding, using a punch with a preliminary molding surface that has a downward protrusion and inclined surface to guide the powder effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If the green compact has uneven upper and lower surfaces with varying thicknesses, then the cutting insert can achieve complex shapes required by modern machining, but density dispersion occurs during powder molding leading to strain and deformation upon sintering
Solution Approach 1:
The invention applies preliminary action by performing a preliminary molding step before the final molding. In this preliminary step, the upper punch creates an uneven upper surface of the green compact that matches the desired final shape. This preliminary action ensures that thick portions are pre-formed, allowing subsequent powder filling to achieve uniform density distribution throughout the compact, thereby preventing density dispersion and deformation during sintering.
Solution Approach 2:
The invention applies local quality by varying the thickness of the green compact at different locations. The upper punch is designed with specific surface features that create locally thicker portions where needed. This local variation in thickness allows the compact to accommodate the complex uneven surface shape while maintaining uniform density, as the preliminary molding ensures proper powder distribution in each local region before final molding.
2Productivity
If a single molding step is used, then the manufacturing process is simple and fast, but the density of raw material powder becomes non-uniform in thick and thin portions
Solution Approach 1:
The invention applies segmentation by dividing the molding process into two distinct segments: a preliminary molding step and a final molding step. The preliminary molding step creates the uneven upper surface and thick portions, while the final molding step completes the densification. This segmentation allows each step to be optimized for its specific function, ensuring uniform density while maintaining overall process efficiency.
Solution Approach 2:
The preliminary molding step serves as a preliminary action that prepares the green compact for the final molding. By first creating the uneven surface and thick portions, the preliminary action ensures that the subsequent final molding can achieve uniform density distribution. This two-stage approach maintains productivity by automating both steps in sequence without requiring complex intermediate handling.
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 ensures a uniform density of the raw material powder in the cutting insert, preventing strain or deformation and enabling the manufacture of high-precision cutting inserts with uneven surfaces.
Implementation Method 1
the upper punch for preliminary molding including the preliminary molding surface having the shape different from the shape obtained by inverting the upper surface of the green compact for a cutting insert in plane symmetry is inserted into the molding space to perform the preliminary molding to the raw material powder filling the molding space
Implementation Method 2
the green compact for a cutting insert which is powder-molding-pressed is sintered to be shrunk to have a substantially similar shape
Data Source
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AI summary
The present invention provides a powder molding press method of a green compact for a cutting insert including: filling a molding space with a raw material powder in a state where a lower punch is inserted from below into a hole portion of a die; performing a preliminary molding by inserting an upper punch for preliminary molding including a preliminary molding surface having a shape different from a shape obtained by inverting the upper surface of the green compact for a cutting insert in a plane symmetry into the molding space from above such that a thick portion between the upper and lower surfaces in the direction of the insert center line is filled with more raw material powder than a thin portion therebetween, relative to a state before the step of performing the preliminary molding; and inserting an upper punch for final molding into the molding space from above to powder-molding-press the raw material powder.