Title: Development of Salt Core Use as an Alternative in Aluminum Alloy Castings

Core Objective of the Research: This research aims to develop an eco-friendly and efficient casting process using salt cores as an alternative to traditional sand cores in the production of complex-shaped castings, commonly required in the automotive industry. The study seeks to overcome the drawbacks associated with sand cores, such as core gas generation, noise, dust, and environmental pollution during core removal.

Main Methodology: The study used a pump body part as a test case. A single-chamber injection mold was designed and manufactured for salt core production. Molten salt was injection-molded to create salt cores. Casting was performed using a conventional tilt casting method. Dimensional accuracy of the salt cores was measured using a Faro Edge Scan Arm HD and compared with a 3D data model. The cooling system was improved to ensure uniform cooling and minimize cracking. After casting, the salt cores were dissolved and removed using water. Surface roughness and internal defects of the castings were analyzed, and comparisons were made with sand core casting processes.

Key Results: The salt core casting process demonstrated several advantages over sand core casting: (1) Elimination of core gas generation, reducing casting defects. (2) Complete core removal without residue, eliminating noise, dust, and environmental issues associated with sand core removal. (3) Superior surface roughness of the castings compared to those produced with sand cores. (4) Comparable casting cycle time to sand core casting. However, challenges remained in accurately predicting shrinkage and the longer solidification time of salt cores compared to sand cores.

Researcher Information:

Affiliation: Nemak İzmir Döküm San.A.Ş., R&D Department
Author: Tülay Hançerlioğlu
Main Research Area: Casting processes, salt core technology

Research Background and Objective:

Industrial Background: Increasing demand for complex-shaped castings in various industries, particularly the automotive sector.
Specific Technical Challenges: Drawbacks of sand cores, including core gas generation, noise pollution, dust generation, environmental pollution, and difficult removal.
Research Goal: Development of an eco-friendly and efficient aluminum alloy casting process utilizing salt cores.

Main Objectives and Research Content of the Paper:

Main Objectives and Research Content: Development and evaluation of a salt core casting process for aluminum alloys, and comparative analysis with conventional sand core casting.
Problems Addressed: Drawbacks of sand core casting, including core gas, noise, dust, environmental concerns, and difficult removal.
Step-by-Step Approach to Problem Solving: (1) Design and manufacturing of injection mold for salt cores. (2) Salt core injection molding. (3) Tilt casting process using the salt cores. (4) Dissolution and removal of salt cores. (5) Analysis of surface roughness and internal defects in the castings. (6) Comparative analysis with sand core casting.
Key Figures: Figures 1-16 (as described in the Korean summary)

Figure 1. Sectional view of the pump body.

Figure 2.1. Injection mold movable side manufactured for salt core

Figure 2.2. Injection mold fixed side manufactured for salt core.

Figure 4. Salt core laser scanning compared with 3D data model.

Figure 5. Salt core exterior surface crack.

Figure 7. Mold inner diameter core insertion

Results and Achievements:

Quantitative Results: No core gas generation in salt core casting; superior surface roughness of salt cores compared to sand cores; comparable casting cycle times.
Qualitative Results: Elimination of noise, dust, and environmental problems associated with sand core removal; improved surface quality of castings.
Technical Achievements: Development of a novel salt core casting process for aluminum alloys; successful addressing of sand core limitations and promoting eco-friendly and efficient casting.

Copyright and References: