Non-destructive Quality Evaluation of the Die- Casting by Laser Control System

Automotive quality demands are getting higher every year. Aluminium die-castings are especially important components in the automotive industry because of their light weight, rigidity, good corrosion resistance and heat dissipation. Since the pressure die-casting process is a very complex procedure, there must also be a number of quality controls to avoid dimensional, internal and surface defects. The dimensional and internal objective quality controls are already implemented on in-line real time production. As for the surface quality control of die-castings only subjective visual control of the worker is used. This subjective visual control of surface is substituted with objective surface quality control by the laser control system. The laser control system acquires the three-dimensional (3D) data by the principle of laser triangulation and analyses the surface defects by LACO (Laser Casting Control) analysis. 3D data representing the measured surface of the die-casting is statistically analyzed and evaluated. It is capable of detecting the most common die-casting surface defects, such as laminations, cold shuts, non-fills, stains and imprints. We found that the LACO system satisfies the requirements for detecting surface defects on diecastings. Combined with the dimensional and internal quality controls, it is a good way of obtaining a total automatic quality inspection with records of die-castings in real time production.