Ru-Mo-W Resistance Heating Elements Balancing Durability and Processability

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Solution Overview

Problem

Conventional resistance heating elements, such as tantalum, have limitations in durability, temperature dependence of electrical resistivity, and processability at room temperature, making them unsuitable for balanced performance in commercial applications.

Innovation Solution

A Ru-Mo-W alloy composition with specific atomic percentages of Mo and W, which can be in powder or paste form, is used to create a resistance heating element with improved durability, electrical resistivity, and processability at room temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If tantalum is used as the resistance heating element material, then processability at room temperature is improved, but durability temperature is insufficient (about 1,600°C)

Engineering Contradiction:

Improveprocessability at room temperatureVSAvoiddurability temperature

Core Design Contradiction:

Ease of manufactureVSTemperature

Solution Approach 1:

The patent uses a Ru-Mo-W alloy composite material that combines the advantages of different metals. Ruthenium provides room temperature processability, while molybdenum and tungsten contribute to high temperature durability. The specific composition range (Mo: 1-49 atomic%, W: 1-45 atomic%, total Mo+W: 30-50 atomic%) creates a composite structure that achieves both ease of manufacture and high temperature resistance simultaneously.

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If tantalum is used as the resistance heating element material, then processability at room temperature is improved, but temperature dependence of electrical resistivity is large making temperature control difficult

Engineering Contradiction:

Improveprocessability at room temperatureVSAvoidtemperature control precision

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The Ru-Mo-W alloy composite material addresses the temperature control issue by combining metals with complementary electrical resistivity characteristics. Ruthenium has low temperature dependence of electrical resistivity, while molybdenum and tungsten provide stable resistivity characteristics at high temperatures. This composite structure achieves reliable temperature control throughout the operating range while maintaining room temperature processability.

Inventive Principle:

Principle #40Composite materials

3Temperature

If tungsten or molybdenum is used as the resistance heating element material, then durability temperature is improved (higher than tantalum), but processability at room temperature becomes difficult requiring heating for production increasing manufacturing costs

Engineering Contradiction:

Improvedurability temperatureVSAvoidprocessability at room temperature

Core Design Contradiction:

TemperatureVSEase of manufacture

Solution Approach 1:

The patent creates a Ru-Mo-W alloy composite where ruthenium serves as the primary matrix material enabling room temperature processing, while molybdenum (1-49 atomic%) and tungsten (1-45 atomic%) are incorporated as strengthening phases that provide high temperature durability. This composite approach allows the material to be processed at room temperature like ruthenium while achieving the high temperature resistance of tungsten-molybdenum alloys.

Inventive Principle:

Principle #40Composite materials

4Temperature

If tungsten or molybdenum is used as the resistance heating element material, then durability temperature is improved, but manufacturing costs increase due to required heating for production

Engineering Contradiction:

Improvedurability temperatureVSAvoidmanufacturing energy consumption

Core Design Contradiction:

TemperatureVSUse of energy by stationary object

Solution Approach 1:

The Ru-Mo-W alloy composite material reduces manufacturing energy consumption by using ruthenium as the base material, which can be processed at room temperature. The addition of molybdenum (1-49 atomic%) and tungsten (1-45 atomic%) in controlled amounts provides high temperature durability without requiring the extensive heating processes needed for pure tungsten or molybdenum. This composite formulation achieves high temperature performance while significantly reducing manufacturing energy requirements.

Inventive Principle:

Principle #40Composite materials

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 Ru-Mo-W alloy composition achieves balanced performance in durability, electrical resistivity, and processability, enabling efficient temperature control and reduced manufacturing costs.

Implementation Method 1

a resistance heating element is heated by applying a DC or AC current to the resistance heating element arranged in the furnace to generate heat in the heating furnace

Methodology Applied

Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP4606917A1Composition, and resistance heating element

Publication Date: 2025.08.27 C&A CORP

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AI summary

This composition includes a Ru-Mo-W alloy having, in atomic%, a chemical composition including Mo: greater than 0% and 49% or less and W: greater than 0% and 45% or less, and the total content of Mo and W in the Ru-Mo-W alloy is greater than 30% and less than 50%.