Optimization and effect of load, sliding velocity, and time on wear behavior of AA8011- 8 wt.% fly-ash composites

The present work discusses the wear and friction studies of aluminium graphite fly ash composite. Three aluminium composites, Al with 10 wt. % fly ash, Al with 10 wt. % graphite, and Al with 5 wt. % fly ash & 5 wt. % graphite were fabricated using the stir casting technique. A linear reciprocating tribometer was used to evaluate the wear and frictional behavior at two distinctive temperatures of 36 °C and 100 °C in dry and lubricated conditions. The aluminium with 10 wt. % fly ash resulted in the least amount of mass loss and coefficient of friction in dry as well as a lubricated condition at 36 °C, however, at a higher temperature of 100 °C the aluminium with 10% graphite exhibits the lowest mass loss and coefficient of friction value. It is concluded that for dry sliding conditions, aluminium fly ash composite could be used as a potential material for applications that are to be operated at room temperature and for high-temperature applications aluminium graphite composite is more suitable.

Effect of fly ash and graphite addition on the tribological behavior of aluminium composites

Sharma¹,

Singh²,

Chaudhary³

2021

Micro groove cutting on the surfaces of Cu-B4C nanocomposites by fiber laser

Arumugam¹,

Lakshmanan

Palani³

2021

Micromachining has evolved into a key facilitating technology and is widely employed today for the creation of complex micro/nano surface features for the parts used in various industries like nano/ micro electro-mechanical systems, medical and telecommunications. At present fiber lasers have made an increasingly significant contribution to micro-fabrications to generate intricate shapes. The increased usage of copper in micro-domains is attributed to the advancements in personal computing and telecom industry. Against this backdrop, this work focuses upon the production of micro-grooves on the surfaces of copper/nano-boron carbide (Cu-B 4 C) metal matrix nanocomposites (MMNCs) by 10 μm fiber laser spot beam. To begin with, Cu-B 4 C MMNCs were synthesized through the powder metallurgical route. Response Surface Methodology-I optimal design was then attempted to optimize the laser machining factors like laser power, number of passes, scanning speed and frequency with the intention to obtain the least surface roughness, minimum kerf width, lower heat affected zone, higher depth and higher material removal. An atomic force microscope is used to inspect the surface characteristics by measuring the roughness values of the surfaces adjacent to the top of micro-grooves. A 3D surface profiler investigated the depth of the groove produced by the fiber laser. Results indicate that a minimum surface roughness of 23.06 nm and a minimum kerf width of 35.49 μm are obtained in the run order 2. Similarly, the groove with a maximum depth of cut of 245.87 μm is achieved in the run order 3. Scanning electron microscopy images helped to examine the surface morphologies and heat-affected zone of the micro-grooved samples.

Optimisation of Corrosion behaviour and hardness of Ni-B₄C Composite coated AZ31 Mg alloy using RSM

Venses¹,

Sivapragash²,

Kumar³

et al. 2022

The optimisation of process parameters in the electroplating process is imperative to improve the effectiveness of coating that meets the industry’s requirements. The present study analyses the influence of the electroplating parameters such as bath temperature, current intensity, and plating time on the hardness and corrosion properties of AZ31 Mg alloy. A preliminary electroplating coating was initially done on the AZ31 Mg alloy with zinc and copper. Subsequently, the AZ31 Mg alloy is coated with Ni-B4C composite by electroplating. Response Surface Methodology (RSM) is used to find the optimum settings for the parameters by minimising the corrosion loss and maximising the hardness. The quadratic regression models were developed for the responses based on the experiments conducted as per the Box-Behnken design method. Scanning Electron Microscopy (SEM), XRD analyses are used to investigate the effectiveness of the Ni–B4C composite coating on AZ31 Mg alloy. It is revealed from the results that the maximum hardness of 140 HV and minimum corrosion mass loss of 0.583 mg cm−2 was obtained for the optimal parameters.