Processing Methods

Composite Structures Manufacturing Technology

MTI has great knowledge and experience about composite structure manufacturing technologies and strong technological capabilities in pregreg/autoclave molding, liquid molding and automatic manufacturing of composite structures. We have manufactured various wing and fuselage structures with pregreg/autoclave molding, sandwich and box structure with liquid molding and large and complex structures e.g. wings, fuselage and inlet duct with automatic manufacturing.

Fields of Application:
Light-weight structures on aircraft e.g. wing and fuselage structures, sandwich structures, inlet duct; automobile; ship, etc.


  Automatic Composite Fiber Placement

Automatic Composite Fiber Placement

  Automatic Composite Fiber Placement

Composite Fuselage Structure-1

Composite Fuselage Structure

Linear Friction Welding

Linear friction welding (LFW), a novel solid state joining technology, is suitable to weld both similar and dissimilar materials. Compared with the traditional welding methods, the benefits of LFW include higher efficiency, higher material utility, less welding defects, and smaller heat-affected zone, making LFW a reliable welding method especially suitable for welding Al and Ti alloy In the past decade, MTI has developed the solutions for welding dissimilar Ti alloy, single crystal alloy and powder metallurgy superalloy.

Fields of Application:
Titanium blisks, aeronautical structures.

Linear Friction Welding
 

Linear Friction Welding-1

Linear Friction Welding

 

Friction Stir Welding

MTI is dedicated itself to the research and application of friction stir welding (FSW) technology and has fulfilled dozens of the national key projects of the cutting-edge research on friction stir welding technology. Many core breakthroughs on the friction stir welding of the metals, including Al alloy, Mg alloy, Cu alloy and Ti alloy, have been made and mastered. In terms of FSW, MTI is the first unit in China establishing the aeronautical standards, such as the standards of “Process of friction stir welding for aluminum alloy aero-structural components” and “Friction Stir Welding Equipments”. Many innovative methods of FSW, for example friction stir spot welding, bobbin friction stir welding, stationary shoulder friction stir welding, have been well developed by MTI and applied to the industry.
There are 14 authorized patents owned by MTI in FSW area. In addition to that, 15 awards have been granted by Ministry of industry and information technology of China, China Federation of machinery industry, and AVIC group.

Fields of Application:
Subway train body joining, car hub welding, large scale flat/curved Al alloy welding


Friction Stir Welding 

Friction Stir Welding

Friction Stir Welding

 

Power Beam Welding

MTI is one of the very first research organizations in China that started to carry out fundamental and applied research on electron beam (EB) welding technology and has achieved remarkable R&D results in heavy-thickness part welding, multi-beam welding with heat treatment, EB welding of additive manufactured structures, etc. A series of research has been carried out at MTI on joint properties evaluation, process optimizing and equipment developing in regard to various materials, e.g. titanium alloy, aluminum alloy, nickel based superalloy, steel and structures that are large, complex or for special use. As one of China’s leading institute in EB welding technology and equipment R&D, MTI is committed to applying our knowledge, experience, and technologies to real industrial context. Our business includes product manufacturing, contract R&D, technical consulting service and special equipment developing.

Fields of application:
- Welding of titanium alloy, aluminum alloy, superalloy, and steel, etc
- Welding of large, complicated and special structures for aerospace, vehicles, high pressure vessels

eb welding

 

 

 

  

Additive Manufacturing

MTI’s additive manufacturing team has been comprehensively exploring power beam additive manufacturing technologies of metal materials and our fields of study include electron beam wire deposition (EBWD), electron beam melting (EBM), direct laser deposition (DLD), selective laser melting (SLM), etc.
At MTI, a series of fundamental and engineering applied research have been carried out regarding special materials, forming processes and equipments for large and complex aeronautical and astronautic metal structures and small/medium-sized precision structures. MTI’s additive manufacturing R&D capability is at a leading position and our aero-products manufactured with additive manufacturing technology have been applied on aircrafts. Our service includes developing customized laser/electron beam additive manufacturing equipments, fabricating structural parts and contract R&D.

Fields of Application:
Large and complex structures, small/medium-sized precision structures, aircraft components, etc

Laser Selective Melting
 

Typical aeronautical Ti component manufactured by electron beam wire-fed at MTI

Typical Aeronautical Ti Component Manufactured by Electron Beam Wire-fed at MTI

 

Laser Shock Processing

Laser shock processing (LSP) is a new surface treatment technology to improve surface performances such as fatigue-resistance, abrasive resistance, stress-corrosion resistance, etc. Through the interaction between high-power pulse nano-second laser and substrate materials, compressive residual stress is induced onto the substrate by high pressure shock wave, which gives contribution to the grains refining, thus improving the serving life and reliability of the products.
Compared with conventional surface processing methods, laser shock processing is a non-contact method without any heat-affected zone. The other advantages of LSP involve absence of contamination particles during the processing, adjustable depth of effect layer depending on the shock wave (up to GPa/Tpa level), and ultra-high strain up to 106 /s. In addition,LSP is a environmental-friendly technology with low energy consumption.

Fields of Application:
Metal surface treatment, e.g. engine fan blade, root, leading edge and trailing edge of blade.

Laser Shock Processing
 

A Moment of Plasma Explosion during Laser Peening

A Moment of Plasma Explosion during Laser Peening

Electro-stream Machining

Small-hole electro-stream machining technology was self developed and patented by MTI. It is a high-energy and high-efficient processing method under the combined effects of both electrochemical and chemical processes. There is no recasting layer, micro-cracks, or heat-affected zone left behind after the machining process, thus retaining the mechanical performance of targeting materials. The achievement of this technology has been well recognized by the clients and granted the National Science & Technology Progress Award.

Fields of Application:
Machining small holes onto metallic products, for application of aerospace components and aero-engine blade.

DSC_1101-1

A Moment of Electro-stream Machining

Shot Peen Forming

MTI has produced large wing and fuselage components for different civil aircrafts by using shot peen forming technology. One example is that the China self-developed advanced regional jet, ARJ 21, has employed the shot peen formed wing panels delivered by MTI. In addition, the numerical controlling (NC) is recruited to improve shot peen forming capability so as to develop the ribbed/unribbed integrated panels of supercritical wings.

Fields of Application:
Aircraft wing & fuselage panels, cylinder skin panels, complex/ribbed integrated panels, etc.

Lower Wing skin panel for ARJ21aircraft(12500mm×1000mm)

Lower Wing Skin Panel for ARJ21 Aircraft

 

SPF/DB

As a pioneer in developing superplastic forming/diffusion bonding (SPF/DB) technology, MTI is leading China’s R&D work on material superplasticity and SPF/DB technology.
In terms of applying SPF/DB into real production, MTI-developed components and structures have been widely used on various aeronautical structures and aero-engine parts. Based on different requirement, our products cover fuselage panel, lid, firewall, aircraft door, airframe structures, aero-engine inlet, state/ rotor blade, wing and appendage, spacecraft fuel tank and other flight vehicle structures.
Regarding fundamental and theoretical research on metallic material superplasticity and superplastic forming, MTI-developed SPF/DB technologies are widely adopted in aeronautical and astronautic industry for processing Ti alloy, Al alloy, Ti-All intermetallic compound and nickel-based superalloy. The benefits of SPF/DB include light-weight manufacture (can make metallic hollow structures), high materials utilization, and manufacture of complex structures.
MTI owns more than 10 sets of SPF/DB equipments with different pressure and working table space and as such, can meet the R&D needs of products with different specifications.

Fields of application:
Forming thin and light-weight integral structures e.g. fuselage panel, lid, aero-engine blade, spacecraft fuel tank, wing and appendage, etc.

SPF/DB
 

spfdb

 

 

 

Coating & Spraying

MTI has dedicated itself to the coating technologies since 1960s. In the past decades, MTI concentrated on various kinds of coating techs including plasma spraying, ultrasonic flame spraying, EBPVD, etc., and is capable to provide both technical support and equipments. The as-prepared coatings, depending on the requirement, present the excellent performances of heat resistance, abrasion resistance, corrosion resistance, bonding, and wear protection. Several patents have been authorized to MTI in terms of plasma spraying.

Fields of Application:
Aviation, aerospace, machine production, bio-industry, automobile, and petrochemical engineering, etc.

Coating Technologies

 

Fastener Manufacturing Technology

New series of bimetal rivets have been developed by MTI to replace the traditional TB2 rivets and high-lock bolts. The rivets were welded by inertia friction welding (IFW) by other MTI facility using Ti64 as the upper body and Ti45Nb as the tail. The relevant testing and assessment onto the products approved that bimetal rivets have obtained high shearing strength and good weld ability at room temperature. In addition, the weight of bimetal rivets is reduced by 20-50% compared with that of bolt-nut lock form.

Bimetal Rivets Manufacturing Technology
 

Bimetal rivets Manufacturing Technology

 

Picture of Inertia Welding Process

Picture of Inertia Welding Process

 

Large twisted blade Measuring

Aiming at the inspection of large twisted engine blades which are composed of complex thin structures, variable curvature, and single-dovetail tenon, MTI has developed a special profile measurement method by combining the rotary continuous scanning probe of 3-axis measurement machine (hardware) and the coordinate system (software) set up by the best fitting method. An innovative method that scans the blade tips by auxiliary coordinate system was accordingly adopted. This effectively eliminates the problems of tip-probe resonance phenomenon, variable geometric tolerance, and reduction of stiffness of blade tips caused by increasing scanning height. This method greatly improves the measurement accuracy of large twisted blade and is one of the significant measuring methods for engine structures.

Inspection of large twisted engine blade

Inspection of Large Twisted Engine Blade