Investigation of heat transfer and mechanical properties of Saccharum officinarum leaf board

Selective Laser Melting (SLM), a laser powder-bed fusion (PBF-L) additive manufacturing method, utilizes a laser to selectively fuse adjacent metal powders. The powders are aligned in a bed that moves vertically to allow for layer-by-layer part construction-Process-related heat transfer and thermal gradients have a strong influence on the microstructural features, and subsequent mechanical properties, of the parts fabricated via SLM. In order to understand and control the heat transfer inherent to SLM, and to ensure high quality parts with targeted microstructures and mechanical properties, comprehensive knowledge of the related energy and mass transport during manufacturing is required. In this study, the transient temperature distribution within and around parts being fabricated via SLM is numerically simulated and the results are provided to aid in quantify the SLM heat transfer. In order to verify simulation output, and to estimate actual thermal gradients and heat transfer, experiments were separately conducted within a SLM machine using a substrate with embedded thermocouples. The experiments focused on characterizing heat fluxes during initial deposition on an initially-cold substrate and during the fabrication of a thin-walled structure built via stainless steel 17-4 powders. Results indicate that it is important to model heat transfer thorough powder bed as well as substrate.

Download Full-text

Effect of Zn Addition on the Microstructure and Properties of Simulated-Brazing 7072Al Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.852.33 ◽

2016 ◽

Vol 852 ◽

pp. 33-37

Author(s):

Xing Long Xu ◽

Dong Yan Ding ◽

Wen Long Zhang ◽

Yong Jin Gao ◽

Guo Zhen Chen ◽

...

Keyword(s):

Heat Transfer ◽

Electron Microscopy ◽

Mechanical Properties ◽

Transmission Electron Microscopy ◽

Tensile Testing ◽

Corrosion Potential ◽

Cladding Layer ◽

Electrochemical Testing ◽

Transmission Electron ◽

Zn Addition

7072Al is widely used as cladding layer for heat-transfer components. In this paper, the microstructure, mechanical properties and electrochemical properties of simulated-brazing 7072Al alloy with Zn addition were investigated. Transmission electron microscopy (TEM) observations revealed that, in the simulated-brazing state, Zn-addition could promote the precipitation in the 7072Al alloy. Tensile testing results indicated that, in comparison with 7072Al alloy, the mechanical properties were improved after Zn-addition. Electrochemical testing results revealed that the simulated-brazing alloy showed a negative shift of the corrosion potential with the addition of Zn element.

Download Full-text

Thermal and Mechanical Properties of Cement Mortar Composite Containing Recycled Expanded Glass Aggregate and Nano Titanium Dioxide

Applied Sciences ◽

10.3390/app10072246 ◽

2020 ◽

Vol 10 (7) ◽

pp. 2246 ◽

Cited By ~ 4

Author(s):

Ali Yousefi ◽

Waiching Tang ◽

Mehrnoush Khavarian ◽

Cheng Fang ◽

Shanyong Wang

Keyword(s):

Heat Transfer ◽

Mechanical Properties ◽

Compressive Strength ◽

Titanium Dioxide ◽

Energy Consumption ◽

Transfer Rate ◽

Water Resistance ◽

Cement Mortar ◽

Residential Buildings ◽

Nano Titanium Dioxide

One of the growing concerns in the construction industry is energy consumption and energy efficiency in residential buildings. Moreover, management of non-degradable solid glass wastes is becoming a critical issue worldwide. Accordingly, incorporation of recycled expanded glass aggregates (EGA) as a substitution for natural fine aggregate in cement composites would be a sustainable solution in terms of energy consumption in the buildings and waste management. This experimental research aims to investigate the effects of EGA on fresh and hardened properties and thermal insulating performance of cement mortar. To enhance the mechanical properties and water resistance of the EGA-mortar, nano titanium dioxide (nTiO2) was used as nanofillers. The results showed an increase in workability and water absorption of the EGA-mortar. In addition, a significant decrease in bulk density and compressive strength observed by incorporating EGA into the cement mortar. The EGA-mortar exhibited a low heat transfer rate and excellent thermal insulation property. Furthermore, inclusion of nTiO2 increased compressive strength and water resistance of EGA-mortar, however, their heat transfer rate was increased. The results demonstrated that EGA-mortar can be integrated into the building envelop or non-load bearing elements such as wall partition as a thermal resistance to reduce the energy consumption in residential buildings.

Download Full-text

MECHANICAL AND THERMAL PROPERTIES OF SAWDUST CONCRETE

Jurnal Teknologi ◽

10.11113/jt.v79.9341 ◽

2017 ◽

Vol 79 (6) ◽

Cited By ~ 1

Author(s):

Ruhal Pervez Memon ◽

Abdul Rahman Mohd. Sam ◽

A. S. M. Abdul Awal ◽

Lemar Achekzai

Keyword(s):

Heat Transfer ◽

Mechanical Properties ◽

Tensile Strength ◽

Thermal Properties ◽

Lightweight Concrete ◽

Physical And Mechanical Properties ◽

Developing Nations ◽

Mechanical And Thermal Properties ◽

Construction Technology ◽

Long Duration

Industrialization in developing countries has resulted in an increase in agricultural output and consequent accumulation of unmanageable agro wastes. Pollution arising from such wastes is a matter of concern for many developing nations. The aim of this study is to investigate the behavior of lightweight concrete and the utilization of sawdust as waste material in concrete. This paper focuses on the manufacturing of concrete which possess long duration heat transfer by using sawdust waste. In this research, cement to sawdust ratio of 1:1, 1:2 and 1:3 by volume was prepared for sawdust concrete, and the ratio of sand was kept constant that is 1. At these ratios, the mechanical and thermal properties like density, workability, strength and heat transfer were measured after, 7, 28 and 56 days of air curing. The tests results show that with the increase in the amount of sawdust, the workability, compressive strength, tensile strength and flexural strength decreased. It also resulted in reduction of heat transfer of sawdust concrete. Taking into account the overall physical and mechanical properties, sawdust concrete can be used in construction technology.

Download Full-text