The surface of zirconia may be damaged during grinding, influencing the mechanical properties of the material. The purpose of this study was to compare the flexural strength of zirconia after different grinding procedures. Twenty bar-type zirconia specimens (21 x 5 x 2 mm) were divided into 4 groups and ground using a high-speed handpiece or a low-speed straight handpiece until the bars were re...

Silicon wafers are used as substrates to build more than 90% of integrated circuits. One of the manufacturing processes for silicon wafers is grinding. This paper reports the investigations of silicon wafer grinding using Finite Element Analysis (FEA). FEA models are first used to study the effects of process parameters on waviness reduction in the grinding of wire-sawn wafers on a rigid chuck....

objectives: micromechanical retention of resin cements to alloys is an important factor affecting the longevity of metal base restorations. this study aimed to compare the bond strength and etching pattern of a newly introduced experimental etchant gel namely nano met etch with those of conventional surface treatment techniques for nickel-chrome (ni-cr) and high noble alloys.  materials and met...

A grinding force model is developed to predict the forces during the face grinding of cast iron and aluminum alloy 319. Design of experiments methods are used to create a response surface of four process parameters: feed rate, inclination angle of the grinding wheel profile, offset angle between the grinding wheel and the workpiece, and the peripheral speed of the wheel. For each material, thre...

Grinding is one of the essential manufacturing processes for producing brittle or hard materials-based precision parts (e.g., optical lenses). In grinding, a grinding wheel removes the desired amount of material by passing the same area on the workpiece surface multiple times. How the topography of a workpiece surface evolves with these passes is thus an important research issue, which has not ...

An on-line monitoring and prediction of surface roughness in grinding is introduced with experimental verification. An adaptive neurofuzzy inference system (ANFIS) is used to monitor and identify the surface roughness online. The system uses a piezoelectric accelerometer to generate a signal related to grinding features and surface finish. The power spectral density (PSD) of this signal is used...

Diamond offers great potential for use as a thermal spreader in various applications, including power electronics and radio-frequency (RF) applications. However, to be used an efficient spreader, the atomically smooth surface of diamond is critical bonded with chips. Herein, polishing technique 2-inch diameter wafer-scale bulk polycrystalline substrate proposed. In this work, 350 μm thick grown...

background and aims. the aim of this study was to evaluate the effect of different etching times on enamel color stability after immediate versus delayed exposure to colored artificial saliva (cas). materials and methods. human first premolars were divided into five groups of twenty. a colorimeter was used according to the cie system on the mid-buccal and mid-lingual surfaces to evaluate initia...