Metallurgically Bonded Wear-Resistant Coating for Undercarriage Components
Solution Overview
Problem
Current undercarriage assembly components of track-type machines, such as track pins and track pin bushings, experience significant wear and corrosion due to harsh operating environments, leading to reduced service life and increased maintenance costs, with existing hardening methods providing limited protection against abrasive and corrosive conditions.
Innovation Solution
A wear-resistant coating comprising a fused hard metal alloy with at least 60% iron, cobalt, or nickel is metallurgically bonded to non-carburized steel components, such as track pin bushings, rollers, and links, before case hardening or induction hardening, to enhance wear resistance and corrosion protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional case hardening or induction hardening is applied to track pins and track pin bushings, then surface hardness is improved, but wear resistance under harsh operating conditions deteriorates
Solution Approach 1:
The patent applies a metallurgically bonded coating comprising a fused hard metal alloy (at least 60% iron, cobalt, or nickel) to the surface of non-carburized steel components. This creates a composite structure where the coating layer provides superior wear resistance (Vickers Hardness 950-1250 HV) while the substrate maintains its structural integrity, resolving the contradiction between surface hardness and wear resistance under harsh conditions
Solution Approach 2:
The patent changes the surface properties by applying a coating with fundamentally different material characteristics than conventional hardening treatments. The coating material composition (iron, cobalt, or nickel-based alloy) and its metallurgical bonding create a surface layer with Vickers Hardness 950-1250 HV, significantly exceeding the hardness achievable through case hardening or induction hardening alone, thereby improving wear resistance while maintaining reliability
2Strength
If carburizing is performed to harden the surface, then hardness is improved, but the ability to metallurgically bond coating deteriorates
Solution Approach 1:
The patent reverses the conventional sequence by applying the metallurgically bonded coating to non-carburized steel components before any case hardening or induction hardening treatment. This preliminary coating application ensures optimal bonding conditions since the non-carburized surface provides better metallurgical compatibility with the coating material, while subsequent hardening treatments then harden both the substrate and the coating together, achieving both excellent bondability and surface hardness
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 solution significantly extends the service life of undercarriage components by providing a wear-resistant layer with a Vickers Hardness of 950 HV to 1250 HV, reducing maintenance needs and operational costs while maintaining a streamlined production process.
Implementation Method 1
a wear-resistant coating that is metallurgically bonded to portions of the component subject to wear
Implementation Method 2
wear-resistant coating comprising a fused hard metal alloy... providing a wear-resistant layer with a Vickers Hardness of 950 HV to 1250 HV
Implementation Method 3
before case hardening or induction hardening
Implementation Method 4
before case hardening or induction hardening
Data Source
AI summary
Undercarriage assembly components of track-type machines having a metallurgically bonded wear-resistant coating and methods for forming such coated undercarriage assembly components is taught herein. The bodies of the undercarriage assembly components, formed of an iron-based alloy, have a hard metal alloy slurry disposed on a surface or into an undercut or channel and then fused to form a metallurgical bond with the iron-based alloy. The wear-resistant coating comprises a fused, metal alloy comprising at least 60% iron, cobalt, nickel, or alloys thereof. The portion of the outer surface of the undercarriage assembly components having the wear-resistant coating corresponds to a wear surface of the component during operation of the endless track of the track-type vehicle.