Hardfaced Wear Part Using a Sacrificial Shell Mold
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Solution Overview
Problem
Existing wear parts in abrasive environments face challenges with wear resistance and durability, particularly in applications like mining and mineral processing, where conventional hardfacing methods require complex and costly molds that struggle with thermal expansion and substrate support issues.
Innovation Solution
The use of a thin metal shell connected to a substrate to create a cavity for infiltration brazing, where hard particulate material is bonded with a metallic brazing material, forming a wear-resistant composite that can be easily fabricated and applied to large, heavy substrates with minimal additional material and cost, while accommodating thermal expansion and substrate orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional hardfacing methods use complex molds, then wear resistance is improved, but device complexity and cost increase
Solution Approach 1:
The patent employs a disposable sacrificial mold made of inexpensive material that is intentionally designed to be consumed or degraded during the brazing process. This eliminates the need for complex, expensive reusable molds while achieving the same hardfacing result. The mold serves its purpose temporarily and is discarded after use.
Solution Approach 2:
The patent changes the material parameters of the mold to match the thermal expansion characteristics of the substrate. By selecting mold materials with compatible thermal expansion coefficients, the process eliminates thermal stress and distortion issues that would otherwise require complex mold designs and procedures.
2Reliability
If conventional hardfacing methods use complex molds, then wear resistance is improved, but manufacturing cost increases
Solution Approach 1:
The patent employs a disposable sacrificial mold made of inexpensive material that is intentionally designed to be consumed or degraded during the brazing process. This eliminates the need for complex, expensive reusable molds while achieving the same hardfacing result. The mold serves its purpose temporarily and is discarded after use.
Solution Approach 2:
The patent changes the material parameters of the mold to match the thermal expansion characteristics of the substrate. By selecting mold materials with compatible thermal expansion coefficients, the process eliminates thermal stress and distortion issues that would otherwise require complex mold designs and procedures.
3Reliability
If conventional hardfacing methods struggle with thermal expansion, then wear resistance is achieved, but manufacturing precision deteriorates
Solution Approach 1:
The patent changes the material parameters of the mold to match the thermal expansion characteristics of the substrate. By selecting mold materials with compatible thermal expansion coefficients, the process eliminates thermal stress and distortion issues that would otherwise require complex mold designs and procedures.
Solution Approach 2:
The patent creates a homogeneous thermal expansion behavior between the mold and substrate by selecting materials with matching expansion coefficients. This ensures uniform dimensional stability throughout the brazing process, preventing warping and maintaining manufacturing precision.
4Reliability
If conventional hardfacing methods have substrate support issues, then wear resistance is achieved, but ease of operation deteriorates
Solution Approach 1:
The patent segments the hardfacing process into distinct functional components: the sacrificial mold provides cavity definition and substrate support, while the brazing material provides the wear-resistant layer. This segmentation allows each component to be optimized independently for its specific function.
Solution Approach 2:
The sacrificial mold acts as an intermediary between the substrate and the brazing material. It provides the necessary support and positioning during the brazing process, then is removed to reveal the finished hardfaced component, simplifying the overall operation.
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 method provides a cost-effective, durable wear-resistant coating with improved thermal expansion matching, reduced risk of cracking, and efficient fabrication for complex shapes, enhancing the lifespan and performance of wear parts in abrasive environments.
Implementation Method 1
formed using infiltration brazing or another brazing technique
Implementation Method 2
The assembly is then heated to activate the bonding powder
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
A wearpart for earth engaging equipment comprises a metal substrate formed for attachment to earth engaging equipment, the substrate having a surface; an expendable, thin sheet metal shell connected to the surface of the substrate by welding or brazing to form a mold with the substrate and define a cavity between the shell and the surface of the substrate; a hard particulate material within the cavity in close proximity to the surface and the shell; a metallic brazing material infiltrated in the particulate material when in molten form to contact the surface of the substrate and the shell and be contained by the shell and substrate, and when solid to bond the hard particulate material to the substrate and the shell to form a wear resistant composite coating on the surface of the substrate.