Attachment 1 PWS Welding Wire.pdf

PERFORMANCE WORK STATEMENT (PWS)

Custom Aluminum Production

1.0 DESCRIPTION OF SERVICES/INTRODUCTION:

The proposed research supports Task 2 shown in Table 1 of the NSWCCD collaborative project with Johns Hopkins University (JHU) proposal aimed at creating custom aluminum wire feedstock for using with Naval wire arc additive manufacturing (WAAM) systems. Task 2 in the original proposal is an ICME-based (Integrated Computational Materials Engineering) alloy development approach to enhance precipitation and grain refinement and the formation of stable equiaxed microstructures. For the purposes of this contract, the performance work statement will focus on Task 2 while Tasks 1 and 3 are handled solely by the ongoing collaboration of NSWCCD and JHU. For the contractor’s portion of Task 2, there are 2 subtasks:

1. Assist in deploying ICME tools and optimizing results to develop 2nd phases (intermetallic primary phases, dispersoids, and precipitates) to produce an equiaxed grain morphology and potentially strengthen and toughen the weldment or WAAM structure.

2. Produce the alloys designed in Task 2 Subtask 1 for

a. Autogenous bead-on-plate weld screening at NSWCCD and characterization at JHU.

b. Identifying best performing materials for production of 1.2 mm wire for printing at NSWCCD and further characterization at JHU.

1.1 ICME design of weld filler alloys

The contractor will collaborate with NSWCCD to design alloys with primary phases and dispersoids designed to inoculate a fine, homogeneous grain structure during weld solidification. Task 2 will involve screening alloy compositions in two iterations of modeling and experiment.

1. Screening iteration 1 shall focus on the optimization of Fe, Mn, Si additions to produce a fine dispersion of primary phases to inoculate a refined dispersion of equiaxed grains.

2. Screening iteration 2, if needed, will optimize primary dispersoid formers that can serve as grain inoculants.

Dispersoids can also be precipitated in the solid state via aging to restrict grain boundary motion and strengthen via precipitation.

1.2 Solidification modeling

The contractor shall be able to utilize the following tools and metrics for solidification modeling:

1. Scheil solidification

2. Columnar to Equiaxed Transition (CET)

3. Crack Susceptibility Coefficient (CSC)

1.3 Solid-state phase transition modeling

The contractor shall utilize solid-state phase transition modeling while designing alloys. The following solid-state modeling tools shall be utilized:

1. Continuous cooling transformation (CCT) diagrams

TASK 1: Tailor, through modeling and experiments, WAAM processing to promote α-Al(Fe,Mn)Si precipitation using commercial Al-Mn-Fe-Si (3xxx and 4xxx) wires.

TASK 2: Use an ICME-based alloy development approach to enhance precipitation and grain refinement and the formation of stable equiaxed microstructures.

TASK 3: Measure the salient room and intermediate temperature mechanical properties (e.g. hardness, tensile, and creep strength) and develop structure-property relations.

Table 1: Specific research tasks to be addressed in the ongoing collaboration between NSWCCD and JHU

2. Non-isothermal calculations

3. Time-temperature transformation (TTT) diagrams

1.4 Optimization methods

Alloy development for WAAM has many parameters that can be adjusted to various different degrees, making identification of the impacts of any one change difficult to parse without extremely large experimental test plans. To reduce the need for these large, time consuming test plans, the contractor shall utilize design of experiments (DOE) during alloy development.

1.5 Custom aluminum extrusion plate production

Alloys will be screened at NSWCCD using autogenous bead-on-plate welding. This means that the experimental alloys shall be fabricated by the contractor as plates. The contractor must be able to produce plate dimensions from 6-12 mm in thickness, 25-50 mm in width and at least one meter in length.

1.6 Custom aluminum alloy weld-wire production

The contractor shall produce five minimum weight 0.5kg batches of custom wire compositions with 1.2 mm diameter for evaluation at NSWCCD. The diameter tolerance of the custom wire shall be compatible with Fronius iWave 400i power supplies, liners, and weld torches.

2.0 BACKGROUND:

As mentioned previously, this contract is in support of the project Aluminum Alloy Development for Hybrid Wire Arc Additive Manufacturing by PI Professor Kevin Hemker and co-PI Professor Mo-Rigen He in the Department of Mechanical Engineering at JHU. The contractor will assist with computational design and production of custom aluminum welding alloys.

This contract supports the funded work of Professors Hemker and He. Tables 1 and 2 are copied from original proposal of Hemker and He and will be used to show how the contractor’s capabilities integrate with the proposed work. The proposal consists of three tasks (Table 1), with the contracting team assisting in Task 2, which includes computational design and production of alloys with enhanced grain refinement and precipitation to form stable equiaxed structures. The contractor will help with Task 2 milestones C, D, E, F in Table 3. ICME in Task 2 stands for Integrated Computational Materials Engineering.

Table 2. Project schedule and milestones from the NSWCCD and JHU collaborative project

Project Tasks and Subtasks:

Year 1: 2024 Year 2: 2025 Year 3: 2026 Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q11 Q12

Task 1: WAAM of commercial wires A B

Rapid assessment w/ OM and hardness G G m-CT to check for voids and geometry H H SEM w/ EDS and EBSD I I Selected TEM / STEM of precipitates J

Task 2: Alloy development C D E F

First milli-tensile experiments K OM, hardness, and m-CT G, H

SEM w/EDS and EBSD of best alloys I I I TEM / STEM of precipitates J J J

Task 3: Mechanical Behavior

RT tensile tests of best alloys K Stabilizing heat treatments L 400°C tensile tests of best alloys M 400°C creep tests of best alloys N NSWCCD milestones and transfers to JHU JHU milestones and transfers to NSWCCD

A: Initial WAAM specimens of ER4043 to JHU G: Melt pool geometry, homogeneity assessment to NSWCCD

B: Additional commercial wire specimens to JHU H: Void and shape assessment to NSWCCD

C: Thermo-Calc ID + procurement of metal-cored wire

I: Chemistry, grain size, texture measurements to NSWCCD

D: 1st generation specimens of custom alloys J: Precipitate ID, v/o, and assessment to NSWCCD

E: 2nd generation specimens of custom alloys K: RT tensile data from JHU

F: 3rd generation specimens of custom alloys L: Annealing + microstructural stability assessments at JHU Contractor to contribute to yellow milestones M: HT tensile results from JHU N: HT creep results from JHU

3.0 OBJECTIVE:

3.1 The contractor shall provide:

3.1.1 Year 1

Three (3) batches of custom aluminum 1.2mm diameter welding wire of minimum weight 0.5kg per batch Five (5) custom alloy aluminum extrusion plates of minimum dimensions 5x25x1000mm

3.1.2 OPTION: Year 2

Three (3) batches of custom aluminum 1.2mm diameter welding wire of minimum

3.1.3 OPTION: Year 3

Three (3) batches of custom aluminum 1.2mm diameter welding wire of minimum

3.2 The contractor shall accomplish:

3.2.1 Year 1

Design report for custom aluminums including:

Solidification modeling of potential custom aluminum alloys as listed in section 1.0 Solid-state transition modeling of custom aluminum alloys as listed in section 1.0 Statistical optimization methods as listed in section 1.0

3.2.2 OPTION: Year 2

Design report for custom aluminums including:

Solidification modeling of potential custom aluminum alloys as listed in section 1.0 Solid-state transition modeling of custom aluminum alloys as listed in section 1.0 Statistical optimization methods as listed in section 1.0

3.2.3 OPTION: Year 3

Design report for custom aluminums including:

Solidification modeling of potential custom aluminum alloys as listed in section 1.0 Solid-state transition modeling of custom aluminum alloys as listed in section 1.0 Statistical optimization methods as listed in section 1.0

4.0 SPECIAL QUALIFICATIONS

4.1 Capabilities to produce custom aluminum alloys and wire

The contractor must have solidification and thermomechanical metallurgical processing equipment.

4.2 Below is a short summary of the equipment required by the contract for this project

• Resistively-heated crucible furnace (minimum 10 kg capacity) with rotary degassing

• Permanent-mold or direct-chill (DC) casting capabilities for minimum of 50mm diameter ingots

• A direct extrusion press capable of producing aluminum plate or rod with dies of various sizes

• Swaging and/or wire drawing that can produce 1.2 mm diameter wire.

5.0 APPLICABLE DOCUMENTS

5.1 N/A

6.0 GOVERNMENT FURNISHED EQUIPMENT/PROPERTY/INFORMATION

6.1 N/A

7.0 DELIVERABLES The contractor shall provide deliverables as described in the PWS/SOW and CDRLs. Format and delivery schedule for deliverables will be outlines in the CDRLs.

7.1 A

NUMBER NAME

A001 (years 1-3) Technical Report

8.0 SECURITY REQUIREMENTS: N/A

9.0 PLACE OF PERFORMANCE

Contractor’s Facility

10.0 PERIOD OF PERFORMANCE

Award through 2028

11.0 TECHNICAL POINT OF CONTACT

To be provided at time of award