Scope and Objectives

SSMA-HLM has been proved. However, it requires manual changing the multiple sub-systems and aligning them for each layer which is cumbersome and impractical for industrial use. MSMA-HLM being developed in this project is the synergic integration of all sub-system under one platform so that all of them are available simultaneously and automatically. MSMA-HLM will be used to produce the near-net shape of an object that will be later finish-milled on a same or another 3-/5-axis CNC machine. MSMA-HLM will have application in the following areas: - Complex aerospace components: The objects with large undercut/overhanging features (such as impeller) can be realize by hybrid kinematics and hybrid layering strategies. Apart from the basic ferrous and Al materials, exotic materials such Titanium and Inconel can also be used. In principle, any metal in wire form amenable for MIG/TIG/laser cladding can be used. - Steam and gas turbine blades: These are typically corrosion-free materials of SS with high Cr content. - Composite tooling with conformal cooling channels: Components and Dies/moulds with conformal cooling channels and Functionally Gradient Materials (FGMs) can be realized by using multiple cladding units with different raw-stock material. The Innovate combination of Y and Z axes through scissor lift proposed in this project may be adopted by the machine tool industry.

Deliverables

Multi Station Multi Axis Hybrid Layered Manufacturing (MSMA HLM) system is the primary deliverable of this project. This is the culmination of our 2 decades of HLM research. We shall execute Transfer of Technology (ToT) agreement with an appropriate machine tool industry for its commercialization. In turn, they can display it in Indian machine tool exhibitions as well as in Form Next 2020. Under this project, several case-studies have been carried out to prove the applications of HLM. Aero engine impeller of GTRE (Figure 4) and structural bracket of ISRO (Figure 5) are two of the significant case studies. Our novel scissor lift kinematics combines Y & Z axes elegantly. This occupies less vertical space and costs less. However, machine tool industry looked down this as an inaccurate lifting device. Its poor accuracy was attributed to the stack up of tolerances of the large are number of pin joints which was a myth, because tolerances do not stack up in Z axis due to gravity. As we shall prove this concept for it technical capability and commercial viability, it can be adopted by machine tool industries. The experiences gained in this project has also helped to initiate research in the areas of Electron Beam Additive Manufacturing (EBAM) in which we are now executing a UAY project on EBAM Powder with AMS, Bangalore and a DST AMT project on EBAM Wire with L&T, Mumbai, together amounting to about Rs. 12.5 Cr funding.

Videos

Scientific Output

The following are the significant scientific outcome of the project -Residual Stress management through optimal path planning and pre & post processing -Alleviating the need for support mechanisms using 5 axis motions -Conformal grown as against horizontal growth using 5 axis motions -Residual Stress management through optimal path planning and pre & post processing Residual Stresses (RS) are substantial in metallic AM due to the high energy involved. As any layer tries to warp upward during solidification which is prevented by the substrate, AM invariably suffers tensile RS as shown in Figure 6. Anisotropy occurs in AM because of open and closed pores present in the objects. Therefore, RS Management (RSM) is very essential in HLM. We approach it in the following four ways Randomizing the path so as to make the heat input uniform (Figure 7a) Design for HLM (Figure 7b) Preheating to reduce the quantum of RS (Figure 7c) Peening to heal the RS by adding compressing stresses (Figure 7d) Alleviating the need for support mechanisms using 5 axis motions While the high deposition rates and amenability for Functionally Gradient Matrix (FGM) are the two most important benefits of cladding used by HLM, lack of support mechanism is its most important limitation which is essential for realizing undercuts. We developed an innovative 5 axis motion path planning system for HLM which captures the falling droplet at the right place by tilting and moving the substrate appropriately. Therefore, although the growth is in horizontal layers, we alleviate the need for support structures through 5 axis motions. Conformal grown as against horizontal growth using 5 axis motions An improved version of building the impeller is shown in Figure 9 in which the features of impeller were divided into 3 axis and 5 axis features so that they could be respectively built in 3 axis and 5 axis HLM systems. This, apart from higher process efficiency, results in less material wastage. This hybrid approach uses planar as well as conformal depositions appropriately. Initially this complex build strategy will be established for only impellers and blisks, subsequently, it will be made generic for all geometries as well.

Results and outcome till date

Under this project, several case-studies have been carried out to prove the applications of HLM. Aero engine impeller of GTRE (Figure 4) and structural bracket of ISRO (Figure 5) are two of the significant case studies. Experimental verifications of the sub-systems of HLM have been done individually. Substantial achievements have been made in RSM through four methods described above. We have patented and published these investigations. The detailed design of the integrated MSMA HLM was evolved over the first 18 months of the project through several design iterations and discussions with the fabricators. The final design shown in Figure 3 went through global tendering and the competitive vendor has been identified. The value of its purchase order is Rs. 140 lakh. We have total sufficient funds to procure it but less under only equipment. We applied for fund transfer to IMPRINT coordinator from other heads to equipment head in May 2019. MHRD has finally given its consent on October 4, 2019 and we are waiting for the final approval from IMPRINT coordinator. As soon as this approval is received, we shall place purchase order. The custom fabrication and integration of MSMA HLM will take about 6 months after the receipt of the Purchase Order.

Societal benefit and impact anticipated

HLM is an Additive Manufacturing (AM) process. As the manufacturing in Nature also largely additive, HLM derives some of the of characteristics of Nature. So, HLM has less wastage of material which means higher sustainability. HLM is a very innovative manufacturing process that makes use of simple processes like arc cladding. It is an integrated transfer type of manufacturing system which will produce with parts with excellent integrity fast. Therefore, it will find easy applications in the Indian industries. It also has export possibilities.

Next steps

As soon as we receive the permission for transfer of the required funds to equipment, we shall place order. Within 6 months, MSMA HLM will be delivered to us. We shall then integrate all sub systems within 2 months We shall then carry out a few benchmarking case studies of actual parts. MSMA HLM has already been patented. We shall sign a ToT agreement with an industry for its commercialization. We shall together conduct a few promotional seminars in important cities. The industrial partner will also display it in appropriate national and international exhibitions.

Publications and reports

In journals:

Negi, S., Kapil, S., Sharma, A., Choudhary, P., Bhargava, P., & Karunakaran, K. P. (2020). Retrofitment of Laser Cladding System with CNC Machine for Hybrid Layer Manufacturing. In Advances in Additive Manufacturing and Joining (pp. 47-59). Springer, Singapore.

Seema Negi, Athul Arun, Sajan Kapil, Prathamesh Joshi, Manivannan. R, K.P. Karunakaran and Parag Bhargava (2020). Review on Electron Beam based Additive Manufacturing, Rapid Prototyping Journal, RPJ-07-2019-0182.R1 (now appearing online; soon in print)

Sajan Kapil, Pravin Kulkarni, Prathamesh Joshi, Seema Negi & K. P. Karunakaran, 2018, Retrofitment of a CNC Machine for Omni-Directional Tungsten Inert Gas Cladding, Virtual and Physical Prototyping, Vol. 14 (3), pp. 293-306.

Sajan Kapil, Prathamesh Joshi, Pravin Kulkarni, Seema Negi, Ranjeet Kumar, and K. P. Karunakaran, 2018, Elimination of Support Mechanism in Additive Manufacturing through Substrate Tilting, Rapid Prototyping Journal, Volume 25 (2), pp. 1155-1165

Sajan Kapil, Fisseha Legesse, Ranjeet Kumar, K. P. Karunakaran, Hybrid Layered Manufacturing of Turbine Blades, Materials Today: Proceedings, Volume 4 (8), 2017, pp. 8837-8847, ISSN 2214-7853

Fisseha Legesse,Sajan Kapil, Hari Vithasth, Viren Sangwan and K. P. Karunakaran, 2017, Additive Manufacturing of H13 Tooling Element with Conformal Cooling Channel Using MIG Cladding, International Journal of Rapid Manufacturing, Vol. 7 (1), pp. 1-24

Sajan Kapil, Fisseha Legesse, Pravin Milind Kulkarni, Prathmesh Joshi, Ankit Desai and K. P. Karunakaran, 2016, Hybrid Layered Manufacturing using Tungsten Inert Gas Cladding, Progress in Additive Manufacturing, 1 (1), pp. 79-91

In conferences:

K.P. Karunakaran, Sajan Kapil, Seema Negi, Michael Sealy, Shengyong Pang, Dmitriy N. Trushnikov, Alain Bernard, 2018, Omni-Directional Cladding for Hybrid Layered Manufacturing, 7th International Conference on Power Beam Processing Technologies (ICPBPT-2018).

K. P. Karunakaran, Sajan Kapil, Seema Negi, A. Bernard, Zhen HONG, Yicha ZHANG, Michael Sealy, Shengyong Pang and Dmitriy N. Trushnikov, 2018, Synergistic Integration of Hybrid Processes and Multiple Technologies, Key note presentation in European Forum on Additive Manufacturing, Centrale Superlec, Paris, June 19-21, 2018.

Sajan Kapil, Seema Negi, K. P. Karunakaran, Omni-directional Cladding, International Conference on Digital Fabrication 2018, IIT Hyderabad, India.

Sajan Kapil, Seema Negi, K. P. Karunakaran, Topology Optimization of the Linkages of a Novel Hybrid CNC machine, National Conference on Multidisciplinary Design, Analysis, and Optimization, 23-24 March 2018, IISc Bangalore, India.

Seema Negi, Sajan Kapil, K. P. Karunakaran, Parag Bhargava, Laser Cladding based Hybrid Layered Manufacturing, Department Symposium 2017, Department of Metallurgical Engineering & Materials Science, IIT Bombay, Mumbai, India.

S. Kapil, Seema Negi, Prathamesh Joshi, Jitendra Sonwane, Arun Sharma, Ranjeet Bhagchandani and K. P. Karunakaran, 5-Axis Slicing Methods for Additive Manufacturing Process, 2017 Annual International Solid Freeform Fabrication Symposium, University of Texas, Austin, USA.

K. P. Karunakaran, Alain Bernard, S. Kapil, Jitendra Sonwane, Seema Negi, Arun Sharma, Rakesh Kumar, Synergistic Integration of Hybrid Processes and Multiple Technologies, 2017 Annual International Solid Freeform Fabrication Symposium, University of Texas, Austin, USA.

Patents

K. P. Karunakaran, S. Kapil and Seema Negi, 2018, Multi-Station Multi-Axis Hybrid Layered Manufacturing System, Indian Patent, Application Number: 201821038516
K. P. Karunakaran, S. Kapil and Pravin Kulkarni, 2016, In-situ Stress Relieving Process for Additive Manufacturing, Indian Patent, Application Number: 201621028306
K. P. Karunakaran, S. Kumar and S. Kapil, (2015), Realization of the composite injection moulds with conformal cooling channels through Hybrid Layered Manufacturing. Indian Patent, Application Number: 4762/MUM/2015
K. P. Karunakaran and S. Kapil, (2015), Elimination of Support Mechanism in Additive Manufacturing through Five Axis Deposition, Indian Patent, Application Number: 3366/MUM/2015.

Scholars and Project Staff

1) Ronald H Ely Project Staff Sep 2018 - ongoing 2) Sajan Kapil Project Manager July 2018 - Nov 2018 3) Praveen Kumar Project Assistant June 2018 - Feb 2019 4) Manivannan Project Research Engineer Dec. 2018 - March 2019

Challenges faced

We did not anticipate so much of paper work and hence tried to manage these with the help of students. We hired a dedicated administrative staff a year ago. Now the papers are moving faster, thanks to her efficient follow up.