Exothermic Fragmenting Material Sintering Process

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for manufacturing fragmenting materials for military applications, such as nose cones and shaped charge liners, do not effectively produce composite materials with exothermic properties that can distribute a lethal cloud of fast-moving fragments upon detonation.

Innovation Solution

A method involving densely packing metal fragments like steel, tantalum, or tungsten into a ceramic container, followed by mixing and sintering with a reactive metal powder, such as zirconium, under high temperature and vacuum conditions to bond the fragments into specific shapes, creating a composite material with exothermic properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If metal fragments are densely packed and sintered with reactive metal powder under high temperature and vacuum, then bonding strength and shape retention are improved, but manufacturing complexity and process difficulty increase

Engineering Contradiction:
Improvebonding strengthVSAvoidmanufacturing complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by controlling sintering temperature (1000-1500°C), vacuum pressure (10^-3 to 10^-6 Torr), and reactive metal powder composition (5-20 wt% of total material) to achieve optimal bonding strength. These parameter optimizations resolve the contradiction by finding the precise conditions where strong bonding is achieved without requiring excessively complex manufacturing processes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system consisting of metal fragments (steel, tungsten, tantalum) bonded by reactive metal powder (zirconium, aluminum, magnesium). This composite approach improves bonding strength by combining the structural integrity of metal fragments with the exothermic bonding properties of reactive metals, while the standardized composite formulation helps manage manufacturing complexity

Inventive Principle:
Principle #40Composite materials

2Use of energy by moving object

If reactive metal powder is used to bond fragments, then exothermic properties are achieved, but manufacturing precision and control difficulty increase

Engineering Contradiction:
Improveexothermic propertiesVSAvoidmanufacturing precision
Core Design Contradiction:
Use of energy by moving objectVSManufacturing precision

Solution Approach 1:

The patent controls the reactive metal powder content (5-20 wt% of total material) and sintering temperature (1000-1500°C) to precisely regulate exothermic reaction intensity. This parameter optimization ensures that sufficient exothermic energy is released for bonding while maintaining manufacturing precision by preventing runaway reactions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses vacuum conditions (10^-3 to 10^-6 Torr) during sintering to control the reactive metal powder's interaction with oxygen. This inert environment prevents uncontrolled oxidation while allowing precise exothermic reactions to occur, thereby maintaining manufacturing precision while achieving the required exothermic properties

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

3Shape

If high temperature sintering is applied, then bonding and shape retention are improved, but energy consumption and process time increase

Engineering Contradiction:
Improveshape retentionVSAvoidenergy consumption
Core Design Contradiction:
ShapeVSUse of energy by stationary object

Solution Approach 1:

The patent optimizes sintering temperature to the range of 1000-1500°C, which is sufficient to activate the reactive metal powder for bonding while avoiding excessive energy consumption. This temperature optimization achieves good shape retention and bonding strength without requiring extremely high temperatures that would dramatically increase energy usage

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes the phase transition and exothermic reaction of the reactive metal powder during sintering. The reactive metal undergoes oxidation and releases heat, which sustains the sintering process and reduces the need for continuous external energy input, thereby improving shape retention while moderating overall energy consumption

Inventive Principle:
Principle #36Phase transitions

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 resulting composite material exhibits enhanced fragmentation and exothermic behavior upon heat exposure, suitable for military applications like warheads, with improved bonding and shape retention.

Implementation Method 1

a reactive material that is exothermic on fragmentation of the warhead. Typically this will be a pyrophoric material that reacts with oxygen

Methodology Applied
Scientific EffectExothermic reaction: Exothermic Reaction

Implementation Method 2

Typically this will be a pyrophoric material that reacts with oxygen

Methodology Applied
Scientific EffectPyrophoricity: Pyrophoricity

Implementation Method 3

The container with the fragments and reactive material are then subjected to a high temperature sinter cycle whereby the reactive material coats the fragments and bonds them together

Methodology Applied
Scientific EffectSintering: Sintering

Data Source

PatentEP2969322B1Exothermic fragmenting material
Publication Date: 2019.01.09 AEROJET ROCKETDYNE INC
  • EP2969322B1 patent drawingFigure 1A~1C
  • EP2969322B1 patent drawingFigure 2~3

AI summary

A method for the manufacture of a composite fragmenting material having exothermic properties includes the steps of packing a mold with preformed metal fragments; filling interstitial spaces surrounding the metal fragments with a reactive metal powder to form a mixture; and then sintering the mixture at a temperature effective to both coat the metal fragments with the reactive metal powder and to bond the metal fragments together. In one embodiment the composite fragmenting material is formed into a nosecone for a warhead.