Ultrasonic Cavitation And The Mechanical Properties Of Metallic Materials

In recent decades, with the rapid development of nonlinear acoustics and improvement of experimental conditions, cavitation potential applications and theoretical value,make it become the focus of acoustics again.The role of corrosion in all cavitation is the most cause for concern. In the space of up to a certain extent, the occurrence of erosion will be free. Cavitation can destroy any materials, including metal and nonmetal materials. Cavitation phenomenon occurs not only in the propeller and the hydraulic structures, irrigation machinery, but also in pipes, pumps, defense industry torpedoes, submarines and other deep water exercise equipment. As the ships, turbines and other fluid machinery continued to power high-speed, cavitation problem has become more common, also cavitation resistance of materials need higher demands.Cavitation on the metal material has a strong destructive effect, so there are threats to people's lives and property.At present, people in the use of cavitation have to face the damage caused by cavitation.So how can we improve the mechanical properties of materials to reduce disasters caused by cavitation?What are the kind of mechanical properties and cavitation erosion? In this paper, for the destructive effects of cavitation erosion, we combined cavitation erosion with the basic theory and principle of tensile test, by making use of cavitation erosion test equipment and tensile test platform to study the occurrence of cavitation erosion and development of properties, using scanning electron microscopic observation of corrosion of materials in the air, the surface topography before and after analysis of the various stages of cavitation process, and focused on cavitation corrosion of metal material tensile strength. As a result, the structure and components for the design, materials, applied research and anti-cavitation research and development of new materials has a certain reference value and practical significance.In this paper,we built the test-bed to study the factors which caused the mechanical properties changed in detail,and on this basis we make the analyze.1.Studied the influence of cavitation rate with time.The same material with different amplitude, the cavitation erosion rate with an empty time change is consistent. Cavitation erosion rate is then decreased, followed by cavitation erosion rate tends to a certain value.2. Studied the influence of amplitude with cavitation erosion rate. Cavitation erosion rate increased with the increase of amplitude, increased to varying degrees in different materials. Smaller in amplitude, cavitation erosion rate of aluminum is relatively small, and high resistance to cavitation. Higher cavitation erosion rate of steel, and the low level of resistance to cavitation. The amplitude is large, and vice versa.3. Studied before and after cavitation, surface morphology changes. Before ultrasonic treatment surface was uniform, but after ultrasonic treatment surface noticeable cavitation pits and gully.4. Studied the influence of the tensile strength of metal materials with cavitation erosion time. The longer cavitation time was, the greater effect on tensile strength.5. Studied the influence of ultrasonic amplitude on the tensile strength of metal materials. At t= 2h, the smaller of the amplitude, the lower effect on tensile strength of metal materials.6. Compared the tensile strength before and after the ultrasonic treatment. After ultrasound treatment the tensile strength reduced significantly. No matter at the same cavitation time or the same amplitude, the tensile strength after cavitation was higher than untreated.