Session: 15-01-01: ASME International Undergraduate Research and Design Exposition

Paper Number: 95019

95019 - Computational Design and Development of Sialon Composites for Cutting Tools 

Owing to its excellent thermomechanical and tribological characteristics, SiAlON has become a promising engineering ceramic material that is widely used for a large range of industrial applications. SiAlON is formed when silicon nitride (Si₃N₄), aluminum oxide (Al₂O₃), and aluminum nitride (AlN) chemically react such that some of the Si-N bonds are replaced by Al-N and Al-O bonds. SiAlON is commonly synthesized in either of the two crystallographic forms, α-SiAlON or β-SiAlON, or their combinations. β-SiAlON is amorphous and has elongated grains and high fracture toughness. On the other hand, α-SiAlON is crystalline and has relatively better hardness and tribological properties. However, its fracture toughness, machinability, and thermal conductivity are relatively poor. This hinders its heat dissipation ability and service life during metal cutting operations. Furthermore, manufacturing SiAlON-based tools has become very costly as a result of its high hardness and low electrical conductivity. Recently, studies have shown that the properties of α-SiAlON are best improved through doping with alkaline/rare earth metals as well as the addition of second phase inclusions to form a SiAlON matrix composite. 

In the present study, a computational design approach is used to design particle-reinforced α-SiAlON ceramic composites with properties tailored for cutting tools application. Both ceramic, as well as metal particles, are considered at the design stage. Effective medium approximation and mean-field computational homogenization schemes are used to predict the effective properties of reinforced α-SiAlON composites using different combinations of inclusions, particle sizes, and volume fractions. The effect of inclusion volume fraction and size, thermal interfacial resistance between the inclusion and matrix, as well as porosity are studied. The predicted properties include thermal conductivity, thermal expansion coefficient, modulus of elasticity, fracture toughness, and electrical conductivity. The properties are optimized to arrive at the most suitable inclusion materials for attaining the functional requirements for the use of SiAlON as an effective cutting tool material. As a validation, several ceramic composite samples are developed via the Spark Plasma Sintering Process (SPS). Microstructural analysis of the sintered samples is conducted using scanning electron microscopy (SEM), optical microscopy (OM), and X-ray diffractometry (XRD). The predicted properties of the desired composite material are measured and compared with that of the computational predictions. The porosity of the obtained composite is estimated using the Archimedes technique in order to relate it with variation in properties, while the hardness is measured using the micro-indentation technique.

Presenting Author: Hasan Syed King Fahd University of Petroleum and Minerals

Presenting Author Biography: I am an undergraduate student at King Fahd University of Petroleum and Minerals (KFUPM), Dhahran, majoring in Mechanical Engineering with a concentration in Materials Engineering. <br/><br/>My research interests are:<br/> - Understanding the properties of materials by integrating experimental and computational techniques<br/> - Material design/optimization, synthesis and characterization of materials for energy, electronics, biomedical, water, environment, etc.<br/> - Manufacturing, modeling, and simulating mechanical structures/devices involving multi-physics

Authors:

Hasan Syed King Fahd University of Petroleum and Minerals
Abba Abubakar King Fahd University of Petroleum and Minerals
Abbas Hakeem King Fahd University of Petroleum and Minerals