Press-fit Pick With Superhard Tip For Wear Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing picks used in industries like asphalt recycling, mining, and excavation have tungsten carbide tips that are prone to rapid wear, necessitating frequent replacements and increased operational costs due to their short lifespan during hard milling operations.
Innovation Solution
A pick design featuring a cemented metal carbide core press-fitted into a steel body, bonded with a superhard material impact tip, optimized for wear resistance through specific geometric configurations and materials like diamond or cubic boron nitride, and a wear-resistant coating on the steel body to enhance durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If tungsten carbide tips are used in picks, then the picks can effectively break up hard materials like asphalt and rocks, but the tips wear out rapidly and require frequent replacement
Solution Approach 1:
The invention uses a composite structure combining a cemented carbide core with a superhard material impact tip. The cemented carbide core provides structural support and shock absorption, while the superhard material tip (such as diamond, cubic boron nitride, or polycrystalline diamond) provides extreme wear resistance. This composite approach allows the pick to maintain its ability to break hard materials while significantly extending the lifespan of the impact tip compared to using tungsten carbide alone.
2Duration of action of stationary object
If a larger cemented carbide core is used to extend pick lifespan, then the durability improves, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The pick is segmented into distinct functional zones: a steel body for shock absorption, a cemented carbide core for structural support and shock distribution, and a superhard material impact tip for wear-resistant material removal. This segmentation allows each component to be optimized for its specific function while being manufactured separately and assembled through brazing, thereby managing complexity through functional decomposition rather than creating a monolithic complex structure.
Solution Approach 2:
Different materials are applied to different parts of the pick based on local requirements: the steel body provides toughness and shock absorption where needed, the cemented carbide core provides structural support and shock distribution in the intermediate zone, and the superhard material provides extreme wear resistance only at the impact tip where material removal occurs. This localized material assignment optimizes performance while managing overall complexity.
3Reliability
If superhard materials like diamond are used for the impact tip, then wear resistance is significantly improved, but the manufacturing cost increases
Solution Approach 1:
Superhard materials are applied only to the impact tip surface where wear resistance is critical, rather than using them for the entire pick. The cemented carbide core and steel body provide sufficient performance for structural functions at lower cost. This localized application of expensive superhard materials significantly reduces overall manufacturing cost while maintaining high reliability where it is most needed.
Solution Approach 2:
The invention creates a cost-effective composite structure by combining expensive superhard materials with more economical cemented carbide and steel materials. Each material is used in the specific zone where it provides the most value, creating an optimized cost-performance balance that would not be achievable with a single material throughout the entire pick structure.
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 design significantly extends the lifespan of picks by distributing impact forces effectively, reducing wear and tear, and improving the ability to break up hard materials like asphalt and rocks, thereby lowering maintenance and replacement costs.
Implementation Method 1
A cemented metal carbide core is press fit into a steel body with an interference of between 1 and 5 thousandths of an inch proximate to a second end of the core
Implementation Method 2
The cemented metal carbide core and the impact tip may be brazed together with a braze material comprising a melting temperature from 700 to 1200 degrees Celsius
Implementation Method 3
The impact tip comprises a superhard material opposite the core. The superhard material may comprise diamond, polycrystalline diamond, cubic boron nitride, refractory metal bonded diamond
Implementation Method 4
a steel body, a cemented metal carbide core press fit into the steel body opposite the shank
Data Source
AI summary
In one aspect of the invention, a pick comprises a shank attached to a base of a steel body, a cemented metal carbide core press fit into the steel body opposite the shank, and an impact tip bonded to a first end of the core opposite the shank. The impact tip comprises a superhard material opposite the core, and the core comprises a second end and a largest diameter. A distance through the body from the shank to the second end of the core is less than the largest diameter of the core.