Laser Processing Laboratory
激光加工實驗室
Location E11-G031
Academic Staff in charge Prof. Chi Tat KWOK; Prof. Kin Ho LO
Technician Po Kee WONG; Hang Cheong WONG
Telephone (853) 8822-8057, 4292

Objective | Facilities | Experiments | Courses supported

 

Objective

Lasers have been applied extensively in industry. They are usually used for cutting, welding, drilling, surface modification, etc. The purposes of this laboratory are

  1. To allow the students to have some ideas of laser technology in manufacturing processes.
  2. To provide facilities for students' final projects and MSc and PhD students' theses.
  3. To serve local industries.

Facilities

1. Corrosion testers

Laser System

The laser system consists of the fiber-couple diode laser module (Laserline LDM 1000-1000) and the CNC XYZ table. Diode laser with near infra wavelength provides high energy absorptivity to metals.

Specifications

Classification Class IV
Central wavelength 900 - 990 nm
Maximum power 2300 W
Beam quality 110 mm rad
Optical fiber 1000 μm

Steps for laser processing:

  1. Design scanning sequences with the aid of drawing software, such as AutoCAD and Corel Draw.
  2. The drawing is converted to a CNC program that can be recognized by the controller of the CNC machine.
  3. Adjust the desired power level and scanning speed of the laser machine.

The laser beam is transmitted through an optical fiber. The high energy beam acts as a heat source and is controlled by the CNC machine for processing.

Applications of laser:

Cladding and alloying

Diode lasers are increasingly used in cladding and coating applications as well as in repair welding for improving corrosion and wear resistances. With a wide range of applications, they have proven themselves to be an extremely innovative technology.

Advantages: tailor-made surface properties, applicable for small area

Hardening

Diode lasers reliably meet all hardening requirements for improved wear protection of machine components, tools, accessories and other implements.

Materials: steel with carbon content > 0.25%

Advantages: localized, high speed, automated, minimum heat distortion, controllable treatment depth

Cutting / Drilling

Diode lasers have excellent beam quality which makes them particularly efficient for melt and blow as well as for oxygen cutting. The compactness of diode lasers provide a whole new degree of mobility in this application.

Advantages: precise, high speed, automated, low heat input, minimum heat distortion, dross free for most materials, good edge quality.

Welding of metals

Diode lasers are used in a wide range of metal welding applications in industrial high volume manufacturing. For example: spot welding in the automotive industry.

Advantages: precise, high speed, automated, excellent weld quality, low heat input, minimum heat distortion, high weld aspect ratio, no filler metal needed.

Experiments

  1. Laser transformation hardening
  2. Laser surface alloying
  3. Laser welding
  4. Laser cutting

Courses supported

EMEB121 Engineering Materials
EMEB351 Advanced Materials for Engineers
EMEB355 Corrosion, Wear and Degradation of Materials
EMEB410 Design Projects
ELME702 Physics of Materials
ELME717 Special Topics in Manufacturing I: Laser Materials Processing
ELME718 Special Topics in Manufacturing II : Surface Engineering