NAME：Wenqing QU GENDER：Male
DATE of BIRTH：Feb. 1, 1972
TITLE：Associate Professor, Beijing University of Aeronautics & Astronautics(Beihang University)
ADDRESS：No. 37 Xueyuan Road, Haidian District, Beijing City, China
WORK PHONE： 86-10-82317702
Sep. 1997 — Dec. 2000 Beihang University, Ph.D, Mechanical Engineering & Automation
Sep. 1994 — July 1997 Beihang University, Master, Welding
Sep. 1990 — July 1994 Beihang University, Bachelor, Welding Process & Equipment
Dec. 2014-Dec.2015 Visiting Scholar, University of Western Antario, Canada
Since Sep. 2003 Associate Professor, School of Mechanical Engineering & Automation(SMEA)，Beihang University
Since Jan. 2003 Staff (Deputy Dean for Graduate Studies), SMEA, Beihang University
Jan. 2001-Dec. 2002 Post-Doctor Researcher, SMEA, Beihang University
Vacuum Brazing of non-metal with metal
The vacuum brazing process of Carbon fiber composites jet tube and niobium alloy using copper-free silver base filler metal was developed, and the laminate injector of stainless steel(or Titanium alloy) was also vacuum brazed, and the heat run had been passed in shanghai in 2009, shown as Fig.1.
High Frequency Induction Brazing of dissimilar metals
The brazing processes of dissimilar metals tube such as Aluminum alloy with stainless steel, Aluminium alloy with Titanium alloy, Titanium alloy with stainless steel were developed, and three patents for invention were authorized, shown as Fig.2. These technologies were used in the validation structure of the tube structures in a certain satellite propulsion subsystem. The brazed tube structures of Titanium alloy with stainless steel were used in the heat exchanger liguate tube of a certain launch vehicle, shown as Fig.3.
Other Brazing Processes of Special structures
The High frequency induction brazing processes of Aluminum alloy square tube with stainless steel tube was developed. After 24 hours marinating in liquid nitrogen, the leak rate of brazed joint is lower than 1×10-10Pa.m3/s, shown as Fig.4. The locule leak detection assembly is the key equipment which detecting whether the rendezvous and docking is successfully or not in the first mission of manned space flight project. We completed the optimization of structure design, and developed the brazing technology of the locule leak detection assembly. This technology has been used in the mission of rendezvous and docking of No. 8, No. 9, and No. 10 of Shenzhou spaceship with No. 1 of Tiangong spacecraft, shown as Fig.5.
Large Area Soldering for Loop Heat Pipe vaporizer structures
As the most important component of LHP(Loop Heat Pipe), the evaporator consists of aluminum alloy saddle seat and stainless steel heat collection pipe. Using the large area soldering process, the aluminum alloy saddle seat and stainless steel heat collection pipe was bonded together. The thermal property is higher nearly ten times than that of the evaporator glued joint by the thermally conductive adhesive. The relevant research results have been applied two patents of invention. Two types of LHP vaporizer brazed structures has been used in the thermal control subsystem of certain satellite and spacecraft.
Low temperature interface diffusion bonding Process
Supported by the superpower and high density of heat flow interface heat transfer enhancement technology, now a new low temperature interface diffusion bonding technology was invented, it can be achieved that bonded at 80℃ but not remelted over 250℃. And the thermal conduction of the interface bonded structure is over 10 times than that of glued interface by the thermally conductive adhesive, shown as Fig.7. The relevant research results have been applied two patents of invention.
Solder Sealing Process of inertial instrument system
The High frequency induction soldering process and the equipment for the aluminum alloy inertial controlling device were developed. The inertial controlling unit can be solder sealed in tens seconds, the heating time is shorter than that using iron, so good quality and productivity can be achieved, shown as Fig.8.
3、Special Active Welding Process
The new DCSP-TIG welding process of Aluminum alloy
Well known, The porosity is the worst problem of Aluminum alloy welding, and Aluminum alloy can not be welded by DC straight polarity (DCSP) TIG welding process, because the compact Al2O3 layer covers on the surface of Aluminum alloy. A new DC straight polarity TIG welding process for Aluminum alloy was developed to wipe away the welded porosity, and 7 patents of invention had been applied. New brazing flux was used to remove Al2O3 and H2 pore in the welding process. No porosity appeared in the welded seam, and the joint property and productive efficiency were elevated, shown as Fig.9.
Active Friction Stir Welding(Soldering) Process
S line is the defect difficult to avoid from FSW seam of Aluminum alloy, caused by Al2O3 layer. The new active FSW process was developed to avoid the appearance of S line，shown as Fig.10. And another active friction stir welding/Soldering process was developed for Aluminum alloy wall panel to improve the fatigue property of Aluminum alloy FSW joint. The relevant results have been applied two patents of invention.
Low-Temperature Metal Bonding process
Many problems exist in the Thermally Conductive Adhesive and conductive adhesive, such as poor heat and electric conduction, short time in service etc. A new metal bonding process has been developed as the replacer of thermally conductive adhesive and conductive adhesive, many metals such as Aluminum alloy, stainless steel, Titanium alloy and copper can be bonded under the temperature of 100℃, with the advantage of excellent heat and electric conduction, long time in service.
Active Soldering process
The process for directly bonding ceramic with metal in air was developed, one patents of invention have been authorized.
4、Microstructures and Properties of bonded joints
Microstructures and Properties of 2219 welded joints
2219 aluminum alloy is the conduithead body metal of china new launch vehicle, its microstructure, property and welding performance has the most important effect on the safety of the welded conduithead. So the microstructures, mechanical properties, and fracture properties of base metal and the welded joints of two heat treatment state(T62, T87) 2219 Aluminum alloy were studied, the welded joints include the variable polarity TIG (VP-TIG) welded joint, variable polarity plasma arc (VPPA) welded joint, friction stir welded (FSW) joint, and FSW/VPPA cross welded joint. The results have the important significance to the welding and safe assessment of launch vehicle conduithead.
Microstructures and Properties of Aluminum alloy FSW joints
The microstructures and properties of FSW joint of Aluminium alloy(such as 2024, 7050, 6082, Al-Li-S-4 alloy etc) were studied, including tensile strength, impact toughness, fracture toughness, fatigue property, shown as Fig.12 and13.
Microstructures and Properties of Brazed joints in electron device
The microstructures and properties of brazed joints of vacuum electron device were studied. Many materials combinations were used in the vacuum electron device, such as oxygen-free copper, stainless steel, iron, Monel, kovar alloy. They are all brazed together in the vacuum electron device, so their microstructures and properties were obtained in order to direct structural design and optimizing of process.
Complex Thermal-mechanical environmental assessment of golden alloy soldered joint in aerospace control subsystem
The microstructures and properties of soldered joints of golden alloy in aerospace control subsystem in complex thermal-mechanical environment were studied, including room temperature tensile test, room temperature creep test, high temperature tensile test, high-low temperature cyclic test, high temperature storage test. The soldered joints include SnPb soldered joint, InPb soldered joint, and InPbAg soldered joint.