Mechanical Engineering

1. DEFECTS IN CASTINGS: casting design, endogenous and exogenous inclusions, oxide films, expansion defects, preventive measures to avoid gas defects, shrinkage defects, contraction defects, hot tearing, distortions and residual stresses, stress relief, dimensional errors, segregations; 2. WELDING METALLURGY: WELDING PROCESSES; METALLURGY OF WELDING: welding joints, hydrogen in steel welds, functions of slags, weld metal solidification, gas porosity and cracks in the fusion zone, heat flow in welding; WELDABILITY; DISTORTIONS AND RESIDUAL STRESSES; WELDING DEFECTS; 3. NON DESTRUCTIVE TESTS: MAIN ASPECTS OF NON DESTRUCTIVE TESTS; LIQUID PENETRANT TESTING: physical principles, procedure for penetrant testing; MAGNETIC PARTICLE TESTING: principle of MPT, magnetizing techniques, dusting on magnetic particles, inspection, demagnetization, sensitivity; ULTRASONIC TESTING: piezoelectric transducers, transducers types, measurement techniques, defects measurement, welded joints inspection, AVG method; RADIOGRAPHIC TESTING: nature of radiation, wave nature of x-rays, absorption and scattering of X-rays in matter, unsharpness, penumbra, radiographic films, contrast, sensitometric curves, exposure diagrams. 4. LIMIT OF ACCEPTABILITY OF DEFECTS

For this course the knowledge of mechanical metallurgy and foundry operations is essential. Students must know the basic principles of fracture mechanics as well as the main metallic alloys and their properties.

Lecture Notes

The activities are organized in: - face to face lectures (for the acquisition of knowledge) - Laboratory tests aimed at acquiring a best knowledge of some course topics - Exercises for solving engineering problems

Attending classes is not mandatory.

For determining the final mark the following aspects will be considered: - the level of knowledge - the ability to correlate different topics - the ability to communicate the acquired knowledge and to illustrate the proposed technical solutions with clarity The minimum grade for passing the exam (18/30) is achieved only if the student proves to know, with a sufficient degree of completeness, the basic principles of non-destructive testings and if he is able to identify the causes of different foundry and welding defects. In order to obtain the highest marks (30/30 cum laude), the student must demonstrate that he has acquired excellent knowledge of all the topics covered in the course, and that he can apply this knowledge to the selection of the most suitable non-destructive method to test a particular mechanical component.

The activities are organized in: - face to face lectures (for the acquisition of knowledge) - Laboratory tests aimed at acquiring a best knowledge of some course topics - Exercises for solving engineering problems