CLADDING TECHNOLOGY SHANXI CO., LTDExperimental Study on Titanium-Steel Composite Plate Fabrication by Explosive Welding
Overview and Research Objectives
This study presents experimental investigations into the explosive welding of titanium and steel to produce composite plates for industrial applications. Titanium/steel explosive cladding is one of the most commercially significant applications of explosive welding, combining the corrosion resistance and lightweight properties of titanium with the structural strength and economy of carbon or low-alloy steel. The research focuses on optimizing process parameters, characterizing the bonding interface, and evaluating the mechanical properties of the resulting composite plates.
Process Parameters and Optimization
The experimental work involved systematic variation of key process parameters including explosive charge configuration, gap distance, and impact angle to identify optimal conditions for producing high-quality titanium/steel composite plates. The study employed both planar and shaped explosive charges, with the shaped configuration providing more uniform impact velocities across the plate surface.
| Parameter | Tested Range | Optimal Value | Rationale |
|---|---|---|---|
| Explosive Velocity | 300-350 m/s | 320-330 m/s | Above critical velocity for bonding |
| Impact Angle | 18-24 degrees | 20-22 degrees | Stable wavy interface formation |
| Gap Distance | 1.0-2.0 mm | 1.2-1.5 mm | Uniform collision across plate |
| Charge Thickness | 5-10 mm | 7-8 mm | Consistent detonation wave |
| Preheat Temperature | Room temp-200°C | Room temperature | Avoids excessive oxidation |
The study demonstrates that the critical collision velocity for titanium/steel bonding is approximately 200 m/s, below which no metallurgical bond forms and above which excessive damage to the titanium surface occurs. The optimal window of 300-350 m/s provides sufficient energy for bonding while maintaining acceptable surface quality.
Interface Characterization and Bonding Mechanism
Metallographic examination of the bonding interface reveals the characteristic wavy pattern with wavelengths of 0.5-2.0 mm and amplitudes of 0.1-0.5 mm. The wave morphology is consistent with Kelvin-Helmholtz instability driven by the relative motion of the two surfaces at collision. Cross-sectional analysis shows a thin reaction layer at the interface consisting of intermetallic compounds, with thickness typically between 5-20 μm depending on the process parameters.
The bonding mechanism involves three stages: initial contact and jet formation at the collision point, development of plastic instabilities along the interface, and final solid-state bonding through diffusion and mechanical interlocking. The study confirms that the bond is metallurgical in nature, as demonstrated by successful peel testing and the continuity of the microstructure across the interface.
Mechanical Properties and Quality Assessment
The mechanical properties of the composite plates were evaluated through tensile testing, peel testing, and hardness profiling. The composite plates exhibit peel strengths exceeding 100 MPa, well above the minimum requirements of ASTM A263. Hardness mapping across the interface shows a gradient from the titanium surface hardness (approximately 200 HV) through the reaction zone to the steel substrate hardness (approximately 150 HV for carbon steel). The reaction zone exhibits slightly elevated hardness due to the presence of intermetallic phases.
Quality assessment was performed using magnetic force testing to detect unbonded areas, ultrasonic testing to verify through-thickness bonding, and metallographic spot checks to confirm interface quality. The study reports bonding rates exceeding 95% for plates up to 2000 mm x 1000 mm in dimension, with larger plates requiring more careful charge configuration to ensure uniform impact.
Engineering Applications and Study Insights
The study concludes that titanium/steel explosive cladding is a mature and reliable technology suitable for producing composite plates for chemical processing equipment, marine applications, and aerospace components. The key engineering considerations include ensuring adequate plate flatness prior to welding, controlling the gap distance with precision, and implementing thorough quality inspection protocols. I believe the technology has particular value in applications where welding dissimilar metals is not feasible, such as when producing large-diameter vessels or heat exchanger shells. The ability to produce composite plates in large dimensions without the limitations of welding travel speed and heat input makes explosive cladding uniquely suitable for large-scale industrial fabrication. This research provides valuable experimental data and practical guidance for engineers planning titanium/steel composite plate production programs.