Orbital Drilling End Mill Geometry for FRP Delamination Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fiber reinforced plastic (FRP) materials exhibit low inter-laminar strength, leading to fiber delamination during machining, which is not effectively addressed by conventional end mills.
Innovation Solution
An end mill with specific geometry features such as a dish angle between 2 and 6 degrees, a helix angle between 5 and 18 degrees, and a primary clearance angle between 10 and 18 degrees, combined with a diamond coating for improved tool life, is designed for orbital drilling of FRP materials to minimize fiber delamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional end mill is used for machining FRP materials, then the machining process can be performed, but fiber delamination occurs due to low inter-laminar strength
Solution Approach 1:
The patent applies parameter changes by optimizing the dish angle (2-6 degrees) and helix angle (5-18 degrees) of the end mill to reduce fiber delamination. These specific angular parameters modify the cutting action to better suit the low inter-laminar strength characteristics of FRP materials, thereby resolving the contradiction between machining capability and fiber delamination prevention.
Solution Approach 2:
The patent employs composite materials by coating the end mill with diamond particles on the cutting edges and surface. This composite structure enhances the tool's ability to machine FRP materials without causing fiber delamination, as the diamond coating provides superior cutting performance and reduces mechanical stress on the delicate fiber-reinforced structure.
2Productivity
If machining is performed on FRP materials, then holes can be created, but tool life is reduced due to material abrasiveness
Solution Approach 1:
The patent uses composite materials by incorporating diamond coating on the end mill surface. Diamond, being the hardest known material, significantly increases tool life when machining abrasive FRP materials. This composite approach maintains holemaking capability while extending the duration of tool action despite the abrasive nature of fiber reinforcements.
3Ease of manufacture
If standard end mill geometry is used, then manufacturing is simple, but hole quality deteriorates with fiber delamination
Solution Approach 1:
The patent applies parameter changes by specifying precise angular parameters (dish angle: 2-6 degrees, helix angle: 5-18 degrees) to improve hole quality and reduce fiber delamination. These modified geometric parameters enhance the cutting action for FRP materials while maintaining reasonable manufacturing complexity, thus resolving the contradiction between manufacturing simplicity and hole quality.
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
The end mill achieves excellent hole quality with reduced fiber delamination and significantly increased tool life, up to 20 times, when used for machining FRP materials.
Implementation Method 1
combined with a diamond coating for improved tool life
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A center or non-center cutting end mill (10) for orbital drilling of fiber reinforced plastic (FRP) materials includes a shank (12), a neck (14), a cutting head (16)and two or more flutes (36, 38). The end mill (10) has a tool geometry with the following features: a dish angle (28) between about 2 degrees to about 6 degrees; a helix angle (44) between about 5 degrees to about 18 degrees; an end teeth radial rake angle (46) between about 0 degrees and about 15 degrees; a peripheral teeth radial rake angle (47) between about 8 degrees and about 16 degrees; a gashing axial rake angle (48) between about 3 degrees to about 10 degrees; and a primary clearance angle between about 10 degrees to about 18 degrees. The end mill is made from a tungsten carbide substrate with cemented cobalt and a diamond coating.