Showing 23 results for Hardness
Veeresh Kumar G B, Gantasala Sreenivasulu, Mohan C B, Ananthaprasad M G,
Volume 19, Issue 4 (12-2022)
Abstract
In the present research work physical, mechanical and tribological behavior of Aluminum (Al) alloy LM13 reinforced with Nano-sized Titanium Dioxide (TiO2) particulates were fabricated, mechanical and tribological properties were investigated. The amount of nano TiO2 particulates in the composite was added from 0.5% to 2% in 0.5 weight percent (wt %) increments. The Al-LM13-TiO2 Metal Matrix Composites (MMCs) were prepared through the liquid metallurgical method by following the stir casting process. The different types of Al LM13-TiO2 specimens were prepared for conduction of Physical, Mechanical, and Tribological characteristics by ASTM standards. Microstructural images, hardness, tensile, and wear test results were used to evaluate the effect of TiO2 addition to Al LM13. Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS), and X-Ray Diffractometer (XRD) were used to examine the microstructure and distribution of particulates in the matrix alloy. In the Al LM13 matrix, microstructure analysis indicates a consistent distribution of reinforced nanoparticles. The attributes of the MMCs, including density, hardness, tensile strength, and wear resistance, were improved by adding up to 1 wt% TiO2. Fractured surfaces of tensile test specimens were studied using SEM pictures. The standard pin-on-disc tribometer device was used to conduct the wear experiments; the tribological characteristics of unreinforced matrix and TiO2 reinforced composites were investigated. The composites’ wear resistance was increased by adding up to 1 wt% of TiO2. The wear height loss of Al LM13-TiO2 composite increased when the sliding distance and applied load were increased. Overall, the Al LM13 with one wt% of TiO2 MMCs showed excellent Physical, Mechanical and Tribological characteristics among all the percentages considered in the present study.
Adeel Hassan,
Volume 20, Issue 4 (12-2023)
Abstract
Friction stir additive manufacturing (FSAM) is a variant of sheet lamination additive manufacturing used to produce large, near-net-shaped 3D parts. Unlike traditional friction stir lap welding, FSAM introduces a new plate to one that is already joined, with the effective area limited to the nugget zone. The present study focuses on exploring the microstructure and microhardness around the nugget zone in a five-plate AA 7075-T651 laminate synthesized at 1000 rpm and 35 mm/min. Microhardness increased vertically in the weldment NZ, reaching 143 HV in the top layer with 2.0 μm fine equiaxed grains. The grains on the advancing and retreating sides were coarser compared to the nugget zone. A W-shaped microhardness profile appeared across layer interfaces. These findings contribute significantly to advancing the FSAM technique, particularly in manufacturing multi-layered, multi-pass laminates.
Zainab Dhyaa Fawzy, Saja Ali Muhsin, Taha Hassan Abood,
Volume 22, Issue 2 (6-2025)
Abstract
Ceramics in dentistry have been mainly recommended from a cosmetic perspective. Yet, the hardness behaviour may limit the application in many cases. Although amber glass is used for medications and chemicals, no studies focus on using amber glass for dental purposes as an additive material. This study aims to investigate the dark amber glass behaviour as a new additive material for dental ceramics. The amber glass powder was prepared using the ball mill technique. For the amber glass powder characterization, the SEM/EDX, particle size, DSC, Ion release, and XRD analysis were tested compared to VITA Lumex® AC ceramic. In addition, the Vickers hardness test was applied for ceramic and ceramic amber with an addition of 0.01g, 0.03g, and 0.05g amber glass powder following the DIN EN ISO 6872/ 2019. Statistically, the ANOVA (post hoc- Tukey) test was used for hardness testing analysis at a significant P-value of (P≤0.05). The results show that the amber glass behaviour and composition elements seem similar to VITA ceramics. The addition of amber glass powder to ceramic shows an increase in the HV hardness of specimens. Overall, it was concluded that the amber glass powder could be a promising material for ceramics to use as an additive powder.
