La-Mo-Ni Hard Particles for Oxide-Stable Sintered Sliding Members
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Solution Overview
Problem
Conventional sintered sliding members using hard particles fail to maintain oxide films in high temperature and low oxidation environments, leading to adhesive wear due to metallic contact, which compromises their wear resistance.
Innovation Solution
Incorporating La, Mo, and Ni within specific ranges in the hard particles, along with an iron-based base material, enhances the oxide film forming ability and wear resistance of the sintered sliding members, particularly in valve seats and valve guides.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional hard particles are used in sintered sliding members, then adhesive wear resistance is initially provided by oxide films, but in high temperature and low oxidation environments, the oxide films cannot be maintained, leading to metallic contact and adhesive wear
Solution Approach 1:
The patent changes the chemical composition parameters of the hard particles by adding La (1-7% by mass) alongside Mo (30-50% by mass) and Ni (10-30% by mass). This compositional parameter change enables the hard particles to form stable oxide films that can withstand high temperature and low oxidation environments, preventing film breakdown and subsequent adhesive wear
Solution Approach 2:
The patent creates a composite hard particle system combining La, Mo, Ni, Mn, and Co in specific proportions. This composite material approach leverages the synergistic effects of different elements: La enhances oxide film stability, Mo provides hardness and wear resistance, and Ni improves oxide film forming ability. The composite structure maintains protective oxide films under severe sliding conditions where conventional single-element or simpler alloy particles fail
2Reliability
If the composition of hard particles is modified to improve oxide film stability, then wear resistance in severe environments is enhanced, but the complexity of material composition increases
Solution Approach 1:
The patent establishes specific parameter ranges for each element (La: 1-7%, Mo: 30-50%, Ni: 10-30%, Mn: ≤10%, Co: balance) to optimize oxide film stability. By defining precise compositional parameters, the patent achieves reliable oxide film formation without excessive complexity, as the ranges provide manufacturing flexibility while ensuring performance
Solution Approach 2:
The patent merges multiple elements with complementary functions into a unified hard particle composition. La is added specifically to enhance oxide film stability, while Mo and Ni provide foundational wear resistance and oxide forming capabilities. This merging of elements with synergistic effects achieves superior oxide film stability without requiring overly complex multi-element systems
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 modified hard particles exhibit improved adhesive wear resistance and manufacturability, maintaining oxide films on the sliding surface, thereby enhancing the overall wear resistance of sintered sliding members in severe sliding environments.
Implementation Method 1
the hard particles having oxide films on the surfaces ensure avoiding or reducing adhesive wear caused by a metallic contact
Implementation Method 2
the hard particles having oxide films on the surfaces ensure avoiding or reducing adhesive wear caused by a metallic contact of the sintered sliding member with a counterpart sliding member
Data Source
AI summary
The present disclosure provides hard particles having improved wear resistance and a sintered sliding member using the hard particles. The present disclosure relates to a hard particle consisting of: 1% to 7% by mass of La, 30% to 50% by mass of Mo, 10% to 30% by mass of Ni, 10% by mass or less of Mn, 1.0% by mass or less of C, with the balance being unavoidable impurities and Co, and to a sintered sliding member using the hard particles.