Manufacturing Technology Today

Open Access Open Access  Restricted Access Subscription Access
Open Access Open Access Open Access  Restricted Access Restricted Access Subscription Access

Densification and Deformation Behaviour of Sintered P/M AL-C-CU-MG Alloys During Cold Upsetting


Affiliations
1 School of Mechanical Engineering, Shanmugha Arts, Science, Technology & Research Academy (SASTRA), Deemed University, Thanjavur-613402, Tamil Nadu, India
     

   Subscribe/Renew Journal


The present investigation is focused on the densification behaviour of sintered aluminium alloys of AI-Cu-C with additions of magnesium powder in varying quantities. The influence of normalizing heat treatment on deformation behaviour has also been investigated. Magnesium powder (-150 μ) has been added in varying percentage to Al-Cu-C alloy phase in order to study the influence of Mg on the deformation, densification and metallurgical structure of the P/M Al alloys mentioned above. Elemental powders of Al, Mg, C &Cu were mixed thoroughly in a pot mill for 8 hrs and the powder blends were compacted In to cylindrical shaped preforms of aspect ratio 0.6, applying a pressure of 125 MPa. in hydraulic press. After sintering at 550 °C for 90 minutes cold upsetting tests were carried out on the preforms. Another set of cold upsetting tests were undertaken after subjecting the sintered preforms to normalizing heat treatment at 500 °C. Density and dimensional measurements were carried out after each step of deformations. Axial upsetting was continued upto the point of appearance of fine surface cracks on the bulged surfaces. The results of the investigations revealed that the normalizing heat treatment notably Influenced the flow stress of the alloys. However It has marginal effects on densifications. Addition of higher percentage of Mg to Al-1% C-1% Cu alloy has also affected the deformation as well as densification behavior. Increasing the Mg content has lead to reduced levels of plastic deformation as well as densification. The combination o f addition of Mg and heat treatment has Influenced the flow stress because adding higher Mg demands higher flow stresses during axial upsetting. Normalizing of the alloys with Mg content enhances the resistance to deformation and densification. Addition of Mg to the alloy AI-C-Cu has reversed the response of the material during cold upsetting. The microstructure of the alloys reveals the presence of numerous rounded and small pores with in the grains and along the grain boundary. It also reveals subtle differences due to normalizing heat treatment.
User
Subscription Login to verify subscription
Notifications
Font Size

Abstract Views: 222

PDF Views: 0




  • Densification and Deformation Behaviour of Sintered P/M AL-C-CU-MG Alloys During Cold Upsetting

Abstract Views: 222  |  PDF Views: 0

Authors

R. Chandramouli
School of Mechanical Engineering, Shanmugha Arts, Science, Technology & Research Academy (SASTRA), Deemed University, Thanjavur-613402, Tamil Nadu, India
D. Shanmugasundaram
School of Mechanical Engineering, Shanmugha Arts, Science, Technology & Research Academy (SASTRA), Deemed University, Thanjavur-613402, Tamil Nadu, India
T. K. Kandavel
School of Mechanical Engineering, Shanmugha Arts, Science, Technology & Research Academy (SASTRA), Deemed University, Thanjavur-613402, Tamil Nadu, India
T. Ashok Kumar
School of Mechanical Engineering, Shanmugha Arts, Science, Technology & Research Academy (SASTRA), Deemed University, Thanjavur-613402, Tamil Nadu, India

Abstract


The present investigation is focused on the densification behaviour of sintered aluminium alloys of AI-Cu-C with additions of magnesium powder in varying quantities. The influence of normalizing heat treatment on deformation behaviour has also been investigated. Magnesium powder (-150 μ) has been added in varying percentage to Al-Cu-C alloy phase in order to study the influence of Mg on the deformation, densification and metallurgical structure of the P/M Al alloys mentioned above. Elemental powders of Al, Mg, C &Cu were mixed thoroughly in a pot mill for 8 hrs and the powder blends were compacted In to cylindrical shaped preforms of aspect ratio 0.6, applying a pressure of 125 MPa. in hydraulic press. After sintering at 550 °C for 90 minutes cold upsetting tests were carried out on the preforms. Another set of cold upsetting tests were undertaken after subjecting the sintered preforms to normalizing heat treatment at 500 °C. Density and dimensional measurements were carried out after each step of deformations. Axial upsetting was continued upto the point of appearance of fine surface cracks on the bulged surfaces. The results of the investigations revealed that the normalizing heat treatment notably Influenced the flow stress of the alloys. However It has marginal effects on densifications. Addition of higher percentage of Mg to Al-1% C-1% Cu alloy has also affected the deformation as well as densification behavior. Increasing the Mg content has lead to reduced levels of plastic deformation as well as densification. The combination o f addition of Mg and heat treatment has Influenced the flow stress because adding higher Mg demands higher flow stresses during axial upsetting. Normalizing of the alloys with Mg content enhances the resistance to deformation and densification. Addition of Mg to the alloy AI-C-Cu has reversed the response of the material during cold upsetting. The microstructure of the alloys reveals the presence of numerous rounded and small pores with in the grains and along the grain boundary. It also reveals subtle differences due to normalizing heat treatment.