Lian Chen

Bio: Lian Chen is an academic researcher from Southwest Petroleum University. The author has contributed to research in topics: Drill bit & Drill. The author has an hindex of 6, co-authored 20 publications receiving 201 citations.

The research status and development trend of additive manufacturing technology

Abstract: The paper first presents a brief review of development courses of additive manufacturing technology and summarizes the development status and the application fields of additive manufacturing technology, then, according to the manufacturing methods, it focuses on the principles and characteristics of several main additive manufacturing technologies. This paper also analyzes the existing problems and challenges of additive manufacturing technology and its future development trend. This paper aims to provide references for the development direction of additive manufacturing technology in developing countries.

Sliding bearing of floating sleeve with forced floating function

Abstract: The invention provides a sliding bearing for a floating sleeve with forced floating function, comprising an inner revolving body, an outer revolving body and the floating sleeve between the inner revolving body and the outer revolving body. The sliding bearing is characterized in that a rolling element groove which is penetrated in radial direction is arranged on the cylindrical surface of the floating sleeve; a rolling element is arranged in the rolling element groove; and the diameter of the rolling element is slightly larger than the wall thickness of the floating sleeve. When the inner revolving body and the outer revolving body rotate oppositely, the diameter of the rolling element is slightly larger than the wall thickness of the floating sleeve, so the rolling element which is deformed by stress can roll between cylindrical surfaces of the inner revolving body and the outer revolving body, and push the floating sleeve to force the floating sleeve to slide, thereby realizing stable rotation of the floating sleeve relatively to the inner revolving body and the outer revolving body. The floating performance of the floating sleeve is less influenced by manufacturing errors of a bearing pair, material performance, surface condition and other factors, so the sliding bearing has longer service life at high speed and heavy load. The sliding bearing can be used for various revolving machinery, in particular to oil drilling machinery enduring heavy load and strong impact.

Wheel type drill for breaking rocks in cutting mode

Abstract: The invention discloses a wheel-type drill for breaking a rock in a cutting mode. The drill comprises a drill body (1) and rotating wheels (2), wherein the drill body (1) is provided with wheel palms (3); the rotating wheels (2) are arranged on the shaft necks (6) of the wheel palms (3) and form rotary connection with the wheel palms (3); external cutting tooth rings (4) are distributed on the rotating wheels (2); and the deviation angle alpha of each rotating wheel (2) is in a range that the absolute value of the alpha is greater than or equal to 20 degrees and less than or equal 90 degrees. Cutting teeth of the invention break the rock in an alternate cutting mode, so that high rock breaking efficiency, uniform abrasion and a good cooling effect are achieved; the service life of teeth is long; bearing operating conditions are good; and the service life of the drill is long.

Additive manufacturing: Challenges, trends, and applications:

Abstract: Additive manufacturing is a recent trend in production processes owing to its many benefits. It can be defined as the process of producing parts through the deposition of material in a layer-by-lay...

Microstructure and mechanical properties of Inconel 625 fabricated by wire-arc additive manufacturing

Abstract: In the present study Inconel 625 alloy fabricated using Cold Metal Transfer (CMT) Wire Arc Additive Manufacturing (WAAM) has been investigated. The microstructure and mechanical properties of the fabricated Inconel625 alloy, and the influence of torch travel speed on the properties of the manufactured specimens were researched. Microstructural studies revealed variation in microstructure in different layers of the specimen, with the bottom layer consisting of fine primary cellular grains. Mechanical properties that include hardness and tensile properties showed that with the increase in the travel speed, average micro-hardness of the manufactured specimens slightly improved from 248 HV to 253 HV. The ultimate tensile strength (UTS) increased from 647 MPa to 687 MPa, while yield strength (YS) increased from 376 MPa to 400 MPa. Results showed that the mechanical performance of the manufactured components by CMT-WAAM method was better than the mechanical properties of Inconel 625 alloy casting parts except UTS, which demonstrated that the Inconel 625 alloys can be fabricated by cold metal transfer process.

Additive Manufacturing for the Aircraft Industry: A Review.

Abstract: Considering the stringent regulations, manufacturing of aircraft parts is often quite complex and time consuming. The multi-million components, multi-tier manufacturing systems and the severe constraints surrounding the sector lead to heavy inventory investments to achieve the just-in-time supply of parts often needed to reduce the airplane ground times. Additive manufacturing evolved allowing for the direct production of complex parts based on digital data with no complex tooling or machinery, a messiah of true just in time production. Appropriate integration of additive manufacturing with the aircraft industry could resolve some of the supply chain and inventory hurdles. Significant progress is already evident in these lines, but the lack of quality assurance attributes and certification standards is hampering the progress. The state-of-the-art of the application of additive manufacturing in the aircraft industry is reviewed in this paper.