Boron Carbide Sheet Lamination for Lightweight Shock Absorption

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Solution Overview

Problem

Existing shock absorbing members using ceramic materials are often heavy, difficult to scale, and costly, with previous approaches complicating production and increasing weight, which hinders practical application in protective equipment.

Innovation Solution

A shock absorbing member is created by bonding multiple sheet-like ceramic members with a bonding layer containing aluminum, copper, or gold, allowing for efficient energy absorption and reduced weight, featuring a stepwise thickness increase and voids at the bonding interface to enhance shock wave deflection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a protective member is made by combining ceramic materials with different properties or same kind with different porosity to achieve intended function, then the member can exhibit desired shock absorption properties, but the production steps become complicated and cost increases

Engineering Contradiction:
Improveshock absorption propertyVSAvoidproduction steps
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The ceramic member is divided into multiple thin sheets (5-1000 sheets) with thickness of 0.1 to 50 mm each, which are then laminated and bonded together. This segmentation allows the use of a simpler bonding process while achieving the desired shock absorption function through the layered structure itself.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the bonding parameters by using metal bonding materials (Al, Cu, Ag, Au) and controlling the bonding temperature (600-1600°C) and pressure (30 kPa or less), enabling simplified production while maintaining reliability.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a protective member combines multiple ceramic materials with different properties to achieve intended function, then the member can exhibit desired shock absorption properties, but the cost increases

Engineering Contradiction:
Improveshock absorption propertyVSAvoidcost
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The invention uses sheets containing the same ceramic material (60 mass% or more boron carbide) throughout the laminated structure, eliminating the need for multiple different ceramic materials. This homogeneous approach reduces material costs while maintaining shock absorption performance.

Inventive Principle:
Principle #33Homogeneity

Solution Approach 2:

The invention employs inexpensive metal bonding materials such as aluminum and copper instead of expensive specialized ceramic bonding materials, significantly reducing production cost while achieving reliable bonding between sheets.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Strength

If a laminated sintered body is produced by sintering under pressurization to achieve structural integrity, then the member can be produced, but it becomes difficult to increase in size

Engineering Contradiction:
Improvestructural integrityVSAvoidsize
Core Design Contradiction:
StrengthVSLength of stationary object

Solution Approach 1:

The invention divides the large-sized member into multiple thin sheets that are bonded together. This allows the production of large-sized shock absorbing members by assembling smaller, manageable sheets without requiring high-pressure sintering of the entire large structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention replaces the high-pressure sintering mechanical system with a low-pressure bonding system using metal bonding materials, enabling the production of large-sized members that would be difficult to produce by conventional pressurized sintering.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If a shock absorbing member uses a thick single-layer ceramic structure to absorb shock energy, then the member can provide sufficient protection, but the weight increases

Engineering Contradiction:
Improveshock absorption capabilityVSAvoidweight
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The invention divides a thick single-layer structure into multiple thin sheets (5-1000 sheets), each contributing to shock absorption. This segmented approach provides sufficient protection while reducing overall weight compared to a solid thick layer.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention creates a composite structure by bonding multiple ceramic sheets with metal bonding materials, achieving a lightweight yet strong shock absorbing member that combines the advantages of ceramic hardness with reduced weight.

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 solution results in a lightweight, high-performance shock absorbing member capable of effectively destroying high-speed projectiles, minimizing fragment energy and preventing shock wave transmission, while being cost-effective and easier to produce.

Implementation Method 1

a step of forming the ceramic bonded body by heating the obtained laminated body at a temperature of 600 to 1600°C

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

at least one metal selected from the group consisting of aluminum, copper, silver, and gold is used as bonding material in the bonding layer

Methodology Applied
Scientific EffectThermal bonding:

Implementation Method 3

a function of absorbing energy that a high-speed projectile or the like has with a high efficiency

Methodology Applied
Scientific EffectShock wave deflection: Shock Wave

Data Source

PatentEP2821381B1Shock absorbing member and method for producing same
Publication Date: 2019.07.24 MINO CERAMIC
  • EP2821381B1 patent drawingFigure 1A~1B
  • EP2821381B1 patent drawingFigure 2~3
  • EP2821381B1 patent drawingFigure 4~5

AI summary

A shock absorbing member 50 having a ceramic bonded body 15 having: a plurality of first sheet-like members 5 each having a ceramic containing 60 mass% or more of boron carbide and each having a thickness of 0.1 to 50 mm; and a bonding layer arranged between the first sheet-like members 5 adjacent to each other, the bonding layer bonding surfaces to be bonded facing each other of the first sheet-like members adjacent to each other, wherein the bonding layer has a bonding material containing at least one metal selected from the group consisting of aluminum, copper, silver, and gold.