Roshan Sebastian

16 Questions 27 Answers 0 Followers

Questions related from Roshan Sebastian

In COMSOL simulation of SLM- AM process, how do we add the powders in cubic packing over the build substrate?

Am trying to simulate the SLM process for a single layer of Alloy 718. I need to add 718 powders of 40 microns thick over the substrate plate and simulate the printing. How could one add up the...

10 October 2019 2,174 10 View

What would be the initial and the ending melt pool dimensions when the laser beam shines on the powder material in the SLM process?

Melt Pool dynamics determine the features of the part produced in the SLM. The question is about the initial and ending melt pool shapes during the 3D printing and how much time would it take to...

07 July 2019 6,196 3 View

In SLM process, what are the reasons for part to protrude out from the surface and how to avoid it?

During the SLM printing process, it was observed that the recoater blade constantly touch the parts and as a result less amount of powders were seen to deposit over the printed part. Why would...

05 May 2019 1,489 4 View

Reference books to learn in depth about Creep in alloys and its various testing methods?

Could you please suggest me a book for understanding more about Creep properties of metal. In addition, I want to know the various testing methods available.

01 January 2019 4,781 8 View

Is it true that the residual stress in EBM process are smaller compared to SLM process due to long time exposure to high temperatures in the former?

I want to know the exact reasons for residual stress formation and the standard adopted practices to avoid them during 3D printing.

12 December 2018 1,481 10 View

What does micro-pores present on the microstructure of additive manufactured alloys signify?

In the analysis of the etched microstructure of the additive manufactured nickel superalloy, micro pores in the nano-meter dimensions were found in the matrix and also on the dendrite structures....

05 May 2018 1,902 7 View

Could anyone suggest books to read about Automobile Crankshafts and their failure mechanisms?

Wants to learn about the basics of Crankshafts and the different failure mechanisms.

02 February 2018 9,534 2 View

Is differential etching for SLM processes associated with the thermal stress or any high-energy associated during the process?

The sample showed processed by SLM shows differential etching with respect to surface and the bulk. The cross-sectional samples after the deposition are etched. What could be the reasons for the same?

02 February 2018 3,865 5 View

How is the heat extracted as the melt pool Solidifies in the Laser Beam Melting Process ?

Consider an hemispherical molten pool, which has a higher temperature at the top surface and a lower temperature at the bottom surface. I am confused about the direction of heat extraction and the...

01 January 2018 7,192 3 View

Why does FCC structured materials Hardness indent does not show the typical depression zone around it, even though the hardness is over 400 HV ?

As per literature, FCC materials show larger depressions around it after hardness indentation. But an additively manufactured sample having hardness around 400 HV and is assumed to be FCC, does...

01 January 2018 5,701 7 View

XRD data for a sample, which is a mix of two dissimilar alloys and its Interface. How to analyse the data and separate out the constituent phases?

The data for a bulk sample is obtained in Powder mode. How could one separate out the constituents using JCPDS search?

09 September 2017 5,639 2 View

What is the appropriate etchant for micro-structure analysis of the Interface between Inconel 625 and Cast iron

In order to examine the micro-structure in cross-section of the Inconel alloy on Cast iron, I'm not able to find a suitable etchant which could give good image. There are various etchants for both...

05 May 2017 8,051 13 View

Why is certain non-metals such as Nitrogen, Phosphorous and Sulfur (in very small wt %) added to INCONEL-625 alloy?

In the Inconel 625 superalloy, the metallic elements have a specific purpose, but I'm unable to find the purpose and application of adding these Non-metals

05 May 2017 5,888 3 View

What are the present application of NC Nickel, its alloys and oxides for Electrocatalysis and hydrogen storage, in Industrial Applications?

Use of Nanocrystalline Nickel and its alloys for Fuel cells, batteries, where HER and OER plays a role.

11 November 2016 486 0 View

Residual stress measurements for Additively manufactured Samples- Correct Procedures ?

Need to measure the residual stress measurements for the additively manufactured Inconel 718 alloy. What would be the correct procedures to measure the residual stress using XRD for the alloy for...

01 January 1970 6,761 8 View

How to store Glacial Acetic Acid for laboratory purpose?

I'm using Glacial Acetic Acid for etching purposes. It's mentioned in MSDS sheets that it should be stored in proper ventilated place with temperatures less than 30 degree Celsius, but should be...

01 January 1970 7,367 1 View