At present, there are no large-scale mass-produced commercial engineering projects adopting metal foam composite blast-resistant doors worldwide. Existing cases fall into three categories: test prototypes developed by universities/research institutes, patented R&D prototypes from enterprises, and lightweight protective structural test schemes for overseas defense sectors. No publicly available large-scale industrial demonstration projects exist.

Market Status

Domestic Cases (Test Prototypes, Patented Prototypes & Live Blast Test Research Cases)

Case 1: Steel Plate Sandwich Composite Blast-Resistant Airtight Door (Civil Air Defense / Tunnel Protective Door Prototype)

Developer: Domestic Civil Air Defense Research Institute + Explosion Impact Laboratory of University

Structural Scheme

Blast-facing high-strength steel plate + 30–80 mm metal foam energy-absorbing interlayer + back steel plate; modular filling inside the whole door leaf. The metal foam serves as an energy-dissipating core layer, which is not directly subjected to tension and shear forces and restrained by steel plates on both sides.

Test Condition

Simulation test of gas explosion shock wave inside tunnels

Core Conclusions

With identical blast resistance indicators, the self-weight of the door leaf is reduced by over 30% compared with traditional reinforced concrete airtight doors. Under explosion impact, the metal foam undergoes plastic collapse to absorb shock wave energy, drastically lowering residual deformation of the door backboard and reducing anchoring loads on door frames and hinges.

Reference Value

Basic structural scheme for lightweight blast-resistant doors; suitable for developing principle prototypes of indoor blast-resistant doors for energy storage cabins.

Case 2: Metal Foam Composite Bulletproof & Blast-Resistant Door

Structure

Outer high-strength armored steel plate (3–6 mm) + 20–100 mm metal foam interlayer + inner steel plate; aramid bulletproof auxiliary layer can be added optionally.

Protection Indicators

Static blast and ballistic tests carried out on prototypes: capable of resisting standard 7.62 mm ammunition and impact from small explosive charges, with certain fire resistance performance.

Target Application Scenarios

Integrated lightweight armored blast-resistant doors for ammunition depots and confidential rooms.

Feature

One of the few domestic enterprises with publicly filed patents for metal foam blast-resistant doors.

Case 3: Comparative Live Blast Test on Graded Density Metal Foam Sandwich Blast-Resistant Door by University (Public Test Data Published in Journal of Vibration and Shock and Explosion and Shock Waves)

Test Setup

Explosion Load

Close-range static blast with 0.5 kg–2 kg TNT equivalent

Measured Test Data

The maximum plastic deformation of the graded metal foam structural door leaf is reduced by 42% versus the solid steel door; the peak pressure of shock wave transmitted to the backboard drops by 55%. The test verifies the advantages of graded-pore metal foam: large pores on the blast-facing side for buffering, and small inner pores for continuous energy absorption.

Engineering Insight

Single uniform foam layers deliver limited performance; graded structures are the key optimization point for blast-resistant doors and can be directly adopted for structural design schemes.

Case 4: Pre-research Prototype of Blast-Resistant Door for Energy Storage Cabinets (Jointly Developed by Domestic New Energy Equipment Manufacturers)

Application Scenario

Isolation blast-resistant doors inside lithium battery prefabricated cabins to prevent deflagration caused by thermal runaway of battery cells.

Upgrade Optimization Roadmap

Basic scheme: steel plate + metal foam interlayer; iterative upgraded scheme adopts through-hole metal alloy foam interlayer for improved high-temperature resistance and water vapor corrosion resistance.

Matched Pain Points of Industry Demand

Floor load capacity of energy storage projects is limited, and civil reconstruction cost for traditional heavy-duty blast-resistant doors is high; customers demand lightweight blast protection solutions.

Current Progress

Simulation and small-specimen impact tests completed; live blast type approval test pending. This cutting-edge pre-research direction is highly aligned with relevant business sectors.

Case 5: Combined Protection System of Prefixed Metal Foam Buffer Layer + Blast-Resistant Door for Tunnels (Verified via Numerical Simulation & Physical Tests)

Scheme Form

Instead of filling metal foam inside the door leaf, an independent sacrificial metal foam buffer layer is installed on the blast-facing side of the blast-resistant door.

Source

Domestic research literatures on military tunnel protection

Advantages

Detachable metal foam components can be replaced separately after blast damage without full door leaf replacement, suitable for working conditions with high explosive equivalent impact.

Two Technical Development Routes for Reference

• Route A (Built-in interlayer inside door leaf): Integrated structure, applicable to medium/low-pressure indoor blast-resistant doors.

• Route B (External sacrificial buffer layer): For heavy-duty protective doors under high blast pressure.

Overseas Cases (Test Schemes from Defense & Material Enterprises)

Case 1: Lightweight Protective Structure Test of Through-Hole Metal Foam (USA)

Application Directions

Protective doors for lightweight defense cabins and vehicle-mounted armored compartments

Technical Features

Adopts through-hole metal foam (instead of closed-cell metal foam) with outstanding high-temperature resistance and corrosion resistance. Most tests simultaneously verify dual functions of shock wave energy absorption and flame retardancy.

Public Test Conclusions

The sandwich composite structure effectively cuts peak stress waves and reduces impact load transferred to door frames; widely applied to vehicle-mounted shelters and small airtight compartment door protection.

Limitation

High material cost; mainly deployed for special equipment overseas with rare large-scale adoption in civil industrial blast-resistant doors.

Case 2: Live Blast Experimental Research on Lightweight Metal Foam Sandwich Blast-Resistant Doors (South Korea)

Document Project Title

Blast Protective Systems using Aluminum Foam Panels

Structure

Prototype blast-resistant door with steel plate-metal foam sandwich core

Core Test Conclusions

The metal foam interlayer acts as a sacrificial energy-absorbing layer to drastically reduce permanent deformation of door leaves and evenly disperse concentrated impact stress under local explosion loads, realizing lightweight design while maintaining equivalent protection rating.

Key Reminder from Research Paper

Metal foam has weak tensile resistance and must be restrained by rigid panels on both sides; bare foam without face plates shall not bear direct pressure loads.

Case 3: Composite Metal Foam Armored Protective Structure (Ballistic & Blast Resistance Tests), North Carolina State University

Research Directions

Blast-resistant doors and vehicle-mounted armored plates

Structural Form

Composite system of ceramic face plate + metal foam core + back plate, which successfully blocks armor-piercing projectiles. The test verifies metal foam’s capacity to slow down fragments and attenuate impact loads.

Reference Value

Provides layered composite design ideas for high-grade bulletproof and blast-resistant armored doors.

Comprehensive Summary of All Cases

① Sufficiently Verified Technical Feasibility

Numerous domestic and overseas prototypes and academic experiments confirm that steel plate-metal foam sandwich structures have obvious advantages over traditional solid steel doors in lightweight design, shock wave attenuation and residual deformation reduction.

② Industrialization Gap

No commercial engineering cases have passed the national standard GB37481 and third-party live blast type approval tests for mass deployment. All existing products remain at prototype/pre-research stage as innovative upgrade solutions.

③ Experience Summarized for Material Selection from All Cases

● Indoor normal temperature & low-corrosion working conditions: conventional metal foam.

● Chemical industry, energy storage scenarios with high-temperature flue gas and water vapor: through-hole metal foam is preferred.

● High-grade bulletproof and blast-resistant scenarios: multi-layer composite structure combining graded metal foam with aramid fiber/ceramic sheets.

④ Two Commercialization Development Routes for Promotion

● Route 1 (Primary Promotion): Modular metal foam interlayer built inside door leaves, targeted at lightweight indoor blast-resistant doors for lithium energy storage and fine chemical industries.

● Route 2: Detachable sacrificial metal foam buffer modules mounted externally on the blast-facing side of doors, oriented to heavy-duty blast protection under high-pressure working conditions.

Project Initiation Promotion Remarks

Many universities and new material manufacturers at home and abroad are developing prototypes of metal foam composite blast-resistant doors, yet no mature standardized products have been launched. Drawing on our accumulated experience in material research, simulation analysis and physical testing for flame venting applications of metal foam, we carry out synchronous R&D of metal foam composite blast-resistant doors to form a complete blast protection product line. Our goal is to build the first domestic commercial demonstration project certified by live blast tests ahead of competitors and establish differentiated competitive edges.