Influence Of Abrasive Size Research Articles

The influence of abrasive size and applied load on abrasive wear of Al-Si–SiCp composite

The influence of abrasive size and applied load on abrasive wear of Al-Si–SiCp composite

Experimental Investigation on Two-Body Abrasion of Cast Aluminum–Alumina Composites: Influence of Abrasive Size and Reinforcement Content

Abstract The occurrence of abrasion is inevitable in most engineering systems. Abrasive wear specifically two-body causes higher material and dimensional loss than other modes of wear. Two-body abrasion is yet to be fully comprehended as it is governed by several intrinsic and extrinsic variables. In this article, tribo-performances of Al-composites were experimentally studied with specific emphasis on the role of abrasive size and amount of reinforcement. AA7075 alloy matrix composites with different amounts of alumina particles were fabricated by the advanced stir-casting method. Besides measurements of density, porosity, and Vickers hardness, in-depth characterizations of microstructures were performed. Specific wear-rate (SWR), coefficient of friction (COF), and abraded surface roughness (SR) of developed materials were measured under two-body abrasion over a vast range of distance, load, velocity, and abrasive size. Under all abrasion conditions, composites exhibited higher SR but lower SWR and COF over alloy; the differences increased with reinforcement quantity. SWR, COF, and SR rose with an increase in abrasive size; however, only SR varied with sliding distance for any material. The effects of different variables on the recorded tribo-performances were explained through identification of various micro-mechanisms of abrasion via extensive post wear characterizations and microstructural features. Finally, the criteria for the occurrence of three-body abrasion even in two-body test configuration were highlighted. The wear coefficient value of 10 × 10−3 was identified as the demarcation between two-body and two-body plus three-body abrasion for Al-matrix composites.

The influence of abrasive size on high-pressure chemical mechanical polishing of sapphire wafer

Demand for sapphire wafer has increased with growth of LED market. Chemical mechanical polishing (CMP) comprises a large part of wafering cost since the CMP process requires approximately 3–6 hours. For longer polishing times, the cost of consumables (COC) in CMP increases the total wafering cost; hence, considerable efforts have been made to decrease the polishing time of sapphire wafers to reduce the COC. There are two main approaches to reduce polishing time: controlling the chemical factor and adjusting the mechanical factor. Controlling the chemical factor is a common approach to manipulating the removal rate and roughness. However, it is hard to control the chemical factor. Instead, this study investigates the effects of various mechanical factors. This paper focuses on the effect of high-pressure CMP on the material removal performance; the maximum applied pressure is ∼800 g/cm2. The removal rate increases linearly with gradual increase of CMP pressure to 800 g/cm2. Finally, the effect of high pressure on the removal rate of, and frictional force on, sapphire wafer during CMP using different sized abrasives is investigated; the effect of the abrasives on the removal rate is likewise analyzed at different pressures.

Research on Prediction Model of Surface Roughness in Ultrasonic Polishing Nano-ZrO<sub>2</sub> Ceramics

The orthogonal test of surface roughness in ultrasonic polishing nano-ZrO2 ceramics was carried out in the present paper. Through the test, the influence of machining parameters on the surface roughness was investigated. The test results showed that the influence of abrasive size on surface roughness is the most remarkable, and the other important factors are the depth of cut, on/off work situation of ultrasonic generator, axial feed speed, and working table speed in turns. Furthermore, through the regressive analysis of test data, an empirical formula of surface roughness was established to select reasonable polishing parameters.