Effect of locally increased melted layer thickness on the mechanical properties of laser sintered tool steel parts

This work investigates the effect of layer thickness on the microstructure and mechanical properties of M300 maraging steel produced by Laser Engineered Net Shaping (LENS®) technique. The microstructure was characterized using light microscopy (LM) and scanning electron microscopy (SEM). The mechanical properties were characterized by tensile tests and microhardness measurements. The porosity and mechanical properties were found to be highly dependent on the layer thickness. Increasing the layer thickness increased the porosity of the manufactured parts while degrading their mechanical properties. Moreover, etched samples revealed a fine cellular dendritic microstructure; decreasing the layer thickness caused the microstructure to become fine-grained. Tests showed that for samples manufactured with the chosen laser power, a layer thickness of more than 0.75 mm is too high to maintain the structural integrity of the deposited material.

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Improving the mechanical properties of tool steel by induction chemical-thermal treatment

Journal of Physics Conference Series ◽

10.1088/1742-6596/2086/1/012200 ◽

2021 ◽

Vol 2086 (1) ◽

pp. 012200

Author(s):

P Palkanov ◽

V Koshuro ◽

A Fomin

Keyword(s):

Mechanical Properties ◽

Surface Layer ◽

Thermal Treatment ◽

Tool Steel ◽

High Speed ◽

Nitride Layer ◽

Surface Microhardness ◽

Gaseous Nitrogen ◽

Gradient Diffusion ◽

Study Results

Abstract The study results of the structure and microhardness of the surface layer of high-speed tool steel after induction chemical-thermal treatment in a gaseous nitrogen-containing medium at a temperature of 900–1100 °C were presented. Due to the strengthening treatment of products a gradient diffusion nitride layer with a thickness of about 200 μm and a surface microhardness of 1950±70 HV1 98 was formed.

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Multi-pass friction stirred clad welding of dissimilar joined AA6061 aluminium alloy and brass

JOURNAL OF MECHANICAL ENGINEERING AND SCIENCES ◽

10.15282/jmes.12.4.2018.22.0368 ◽

2018 ◽

Vol 12 (4) ◽

pp. 4285-4299

Author(s):

Nora Osman ◽

Zainuddin Sajuri ◽

Mohd Zaidi Omar

Keyword(s):

Mechanical Properties ◽

Tool Steel ◽

Microstructural Analysis ◽

Welding Process ◽

Fusion Welding ◽

Tool Steels ◽

Aa6061 Aluminium Alloy ◽

Aisi D2 ◽

Semi Solid ◽

Aisi D2 Tool Steel

Tool steels are commonly used to cut metal materials due to their distinctive hardness, resistance to abrasion and deformation. However, tool steels are difficult to be joined using conventional fusion welding process. In this study, a thixotropic property of metal was utilised to butt-join an AISI D2 tool steel by using uncommon direct partial re-melting (DPRM) method. A high frequency of induction heating is used to apply the DPRM method. From the recent study, there are many methods in achieving the globular microstructure with the success of semi-solid joining process. Though, very less information on the microstructural effect of semi-solid joining on the mechanical properties was reported. This study aims to analyse the effect of uniaxial force on the microstructural evolution and mechanical properties of the thixo-joint of D2 tool steel. The microstructural analysis showed the diffusion occurred between the grains of the thixo-joint sample with 2.5 N uniaxial force. The maximum strength of the thixo-joint sample with force was 652 MPa. This was slightly higher than the as-received sample and the thixo-joint sample without force. The average hardness value of the thixo-joint sample was 400 HV due to the transformation of ferrite to the metastable austenite.

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Process Parameter Optimization in Fused Deposition Modeling (FDM) Using Response Surface Methodology (RSM)

10.21203/rs.3.rs-122421/v1 ◽

2020 ◽

Author(s):

Muhammad Salman Mustafa ◽

Muhammad Qasim Zafar ◽

Muhammad Arslan Muneer ◽

Muhammad Arif ◽

Farrukh Arsalan Siddiqui ◽

...

Keyword(s):

Mechanical Properties ◽

Response Surface Methodology ◽

Impact Strength ◽

Response Surface ◽

Layer Thickness ◽

Fused Deposition Modeling ◽

Experimental Results ◽

Fused Deposition ◽

Deposition Modeling ◽

Printing Parameters

Abstract Fused Deposition Modeling (FDM) is a widely adopted additive manufacturing process to produce complex 3D structures and it is typically used in the fabrication of biodegradable materials e.g. PLA/PHA for biomedical applications. However, FDM as a fabrication process for such material needs to be optimized to enhance mechanical properties. In this study, dogbone and notched samples are printed with the FDM process to determine optimum values of printing parameters for superior mechanical properties. The effect of layer thickness, infill density, and print bed temperature on mechanical properties is investigated by applying response surface methodology (RSM). Optimum printing parameters are identified for tensile and impact strength and an empirical relation has been formulated with response surface methodology (RSM). Furthermore, the analysis of variance (ANOVA) was performed on the experimental results to determine the influence of the process parameters and their interactions. ANOVA results demonstrate that 44.7% infill density, 0.44 mm layer thickness, and 20C° printing temperatures are the optimum values of printing parameters owing to improved tensile and impact strength respectively. The experimental results were found in strong agreement with the predicted theoretical results.

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