Aqeel Ahmed ¹, M. S. Wahab ¹, A. A. Raus ¹, K. Kamarudin ¹, Qadir Bakhsh ¹, Danish Ali ¹

Affiliations
1 Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, Parit Raja, Batu Pahat, Johor, MY

Abstract

Background/Objectives: Mechanical and thermal properties of aluminum-based piston alloys are mainly depend on the heat treatment. Conventional heat treatment techniques are also not resulted to that level where it can be used for piston of downsized engine. Methods/Statistical Analysis: Around 30 papers were reviewed to understand the thermal effects and consequences on the Al Si piston alloy. Findings: From the literature it can be understood that two-step solution treatment of the Al Si alloy resulted the good mechanical properties then the single step solution treatment. Heat treatment at 540°C for 8 h and aging at 190°C for 8 h is correctly choice to achieve optimum mechanical properties by heat treatment. To calculate the temperature effect and heat transfer to the engine piston crown, the spatial and time averaged combustion side boundary condition is a most favorable and suitable treatment method within engineering approximations. For temperature and thermal stress distributions for a coated surface piston crown, the coating surface temperature increased with coating thickness by decreasing rate and the best results are at 1 mm coating. Application/Improvements: The coated piston has low thermal conductivity then the uncoated piston.

Keywords

Al-Si Piston Alloy, Heat Treatment, Mechanical Properties, Thermal effects, Thermal Properties.

Full Text

   

Aqeel Ahmed ¹, M. S. Wahab ¹, A. A. Raus ¹, K. Kamarudin ¹, Qadir Bakhsh ¹, Danish Ali ¹

Affiliations
1 Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, Parit Raja, Batu Pahat, Johor, MY

Abstract

This paper is about the mechanical properties and shape of the automobile piston in the engine. Currently downsizing of the engine is attractive field for the research which benefitted in the reduction of fuel consumption and emission pollutants from the engine. While on the other side various pressure boosters attached with the engine piston-cylinder to maintain the output power at the bar/more than the bar. These attachments cause to produce high stresses and displacement vectors in the piston-cylinder and the gas forces generated during the combustion cause to produce thermal stresses on the face of the piston which sometime may leads to the failure of piston material. To withstand all these problems the material must be strong enough. Al-Si alloy is the main alloy material to manufacturing the piston because of low co-efficient of thermal expansion, minimum weight, high hardness and strength and good wear resistance properties. In result; Shallow depth Combustion Chamber (SCC) is most suitable for low speed while Omega Combustion Chamber (OCC) is preferred for high speed, but both combustion chamber produce high amount of NOx. Maximum suitable percentage is of Si is up to 12% to 19%. While centrifugal casting is most right method to manufacture the piston and heat treatment at 540°C for 8 h and aging at 190°C for 8 h is correctly choice to achieve optimum mechanical properties by heat treatment. The ingredient material of the Al-Si alloy, the casting techniques and heat treatment techniques directly affects the mechanical properties of the piston in downsizing engine. A very careful observation is required during the manufacturing of automobile piston to achieve desired mechanical properties.

Keywords

Alloying Elements, Casting Techniques, Hypereutectic Al-Si Piston alloy, Mechanical Properties, Shape of the Piston.

Full Text

   

Bhagwan Das ¹, M.F.L. Abdullah ¹, Mohd. Shah Nor Shahida ¹, Qadir Bakhsh ¹

Affiliations
1 Universiti Tun Hussein Onn Malaysia (UTHM)

Abstract

In optical communication systems, semiconductor lasers are widely in use as an optical source but the performance of laser are limited due to temperature variation, design incompetency, and power consumption issues. The direct output of semiconductor laser may destroy the additional component attached in the system. In this research, semiconductor laser, driver is implemented by utilizing the current mode logic technique to control the output of semiconductor laser. Current Mode Logic (CML) is one of the compatible technique to work integeratedly with optical components. CML based design of semiconductor laser driver has achieved the current ranges from 5.6 mA to 6.8 mA and efficiently working up to 10 GHz frequency and consume 75% less power than typically available laser drivers. In future, the semiconductor laser may have implemented using System on Chip (SoC) configuration to make the design more energy efficient, in terms of temperature sensitivity and power consumption.

Keywords

Current Mode Logic, Driver Circuits, N-Metal Oxide Semiconductor Transistor, Semiconductor Lasers, Switching Efficiency

Full Text