Mechanical Properties and Chain Orientation in Single Point Incremental Forming of Semi-Crystalline Polyamide

2016 ◽  
Author(s):  
Mohammad Ali Davarpanah ◽  
Shalu Bansal ◽  
Rajiv Malhotra
Keyword(s):  
Mechanical Properties ◽  
Incremental Forming ◽  
Single Point ◽  
Polymer Surfaces ◽  
Single Point Incremental Forming ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Chain Orientation ◽  
The Cost ◽  
Tool Rotation

Incremental forming is an emerging technique for reducing the cost of tooling, increasing the flexibility and reducing the thermal energy usage in forming of thermoplastic polymer surfaces. This paper examines the effect of Single Point Incremental Forming (SPIF) on the mechanical properties of a semi-crystalline Polyamide (Nylon 66) material. The effects of incremental depth and tool rotation speed on these properties, and on the sheet temperature during forming are quantified. Differential Scanning Calorimetry and X-ray Diffraction are performed to understand changes in crystallinity and chain orientation of the polymer due to SPIF. It is found that the formed material has a substantial higher toughness and ductility, but reduced yield stress and Young’s modulus, as compared to the formed material. Stress relaxation tests show similar relaxation behavior for the formed and unformed polymer. The effect of SPIF on the chain orientation and its link to the mechanical properties are discussed.

Influence of Single Point Incremental Forming on Mechanical Properties and Chain Orientation in Thermoplastic Polymers

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Mohammad Ali Davarpanah ◽  
Shalu Bansal ◽  
Rajiv Malhotra
Keyword(s):  
Mechanical Properties ◽  
Temperature Rise ◽  
Incremental Forming ◽  
Single Point ◽  
Degree Of Crystallinity ◽  
Single Point Incremental Forming ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Lower Yield Stress ◽  
Chain Orientation

Incremental forming of thermoplastic surfaces has recently received significant interest due to the potential for simultaneous reduction in thermal energy consumption and in part-shape specific tooling. This paper examines the mechanical properties and the chain orientation of the formed material in single point incremental forming (SPIF) of amorphous polyvinyl chloride (PVC) and semicrystalline polyamide sheets. Tensile and stress relaxation properties of the formed polymers are compared to those of the unformed polymer. The effect of incremental depth and tool rotation speed on the above properties, and on the temperature rise of the sheet during SPIF, is quantified. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) are used to compare the chain orientation and crystallinity of the formed and the unformed polymers. It is observed that the formed material has greater toughness and ductility, but lower yield stress and reduced Young's modulus, as compared to the unformed material. We also observe deformation-induced chain reorientation in the formed polymer, with minimal change in the degree of crystallinity. The link between the SPIF process parameters, temperature rise of the polymer during SPIF, change in chain orientation, and change in mechanical properties of the polymer is discussed.

Hot Single Point Incremental Forming of Ti-6Al-4V Alloy

2014 ◽  
Vol 611-612 ◽  
pp. 1079-1087 ◽  
Author(s):  
Mikel Ortiz ◽  
Mariluz Penalva ◽  
Mildred J. Puerto ◽  
Petr Homola ◽  
Václav Kafka
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Incremental Forming ◽  
Single Point ◽  
Metal Alloy ◽  
Hot Forming ◽  
Lead Times ◽  
Single Point Incremental Forming ◽  
Aeronautical Industry ◽  
Reduction Of Costs

The lightweight metal alloy Ti-6Al-4V is widely used in the aeronautical industry due to its excellent mechanical properties. However, it is known the difficulty to deform Ti-6Al-4V sheets at room temperature because of its microstructure conditions. The present work focuses on the evaluation of formability of Ti-6Al-4V sheets using hot single point incremental forming (SPIF) process which it seems appropriate to produce small batches of parts due to its flexibility as it allows a significant reduction of costs and lead times. In order to characterize the SPIF of Ti-6Al-4V under hot forming conditions, a set of forming trials evaluation tests was carried out. The obtained results have allowed identifying the key process features and have demonstrated the potential of the proposed approach to hot form of small amounts of Ti-6Al-4V parts.

Implementing Thermomechanical Properties of 22MnB5 Steel during Hot Single-Point Incremental Forming

2017 ◽  
Vol 890 ◽  
pp. 362-366 ◽  
Author(s):  
Amar Al-Obaidi ◽  
Verena Kräusel ◽  
Dirk Landgrebe
Keyword(s):  
Mechanical Properties ◽  
Incremental Forming ◽  
Sheet Material ◽  
Single Point ◽  
Thermomechanical Properties ◽  
Alloy Sheet ◽  
Process Time ◽  
Single Point Incremental Forming ◽  
Cnc Milling ◽  
Forming Process

The strategy in manufacturing hardened parts used in car bodies is to tailor the mechanical properties. This is done by combining together a high-strength region and a high-toughness region to ensure the crash performance required. Other successive secondary operations such as trimming, joining and welding can be improved as a result of the tailoring process. In this work, the mechanical properties of 22MnB5 alloy sheet material produced by single-point incremental forming have been tailored. For this purpose, the sheets were locally heated by induction during the forming process and subsequently cooled. The sheet temperature was controlled by the CNC milling machine feed rate and induction power. As a result, the produced tailored parts consist of three different regions: ductile, transition and hardened regions. The Vickers hardness values were 583 HV1 and 175 HV1 for the hardened and ductile regions, respectively. The proposed application allows forming and quenching at the same time without transfer and to reduce the process time.

scholarly journals Influence of Forming Parameters on the Mechanical Behavior of a Thin Aluminum Sheet Processed through Single Point Incremental Forming

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1461
Author(s):  
Muhammad Ilyas ◽  
Ghulam Hussain ◽  
Haris Rashid ◽  
Mohammed Alkahtani
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Residual Stresses ◽  
Strain Hardening ◽  
Incremental Forming ◽  
Single Point ◽  
Strain Hardening Exponent ◽  
Single Point Incremental Forming ◽  
Forming Parameters ◽  
Tool Diameter

Incremental sheet forming (ISF) is an economical process for batch production. This paper investigates post-forming mechanical properties with an emphasis on the relationship between residual stresses, strengths, micro-hardness and the strain-hardening exponent. Moreover, the influence of important process parameters on the post-forming tensile properties and hardness is analyzed. A Taguchi statistical analysis method is applied to study the effect of forming parameters and identify the best combinations to enhance the mechanical properties of the commercial aluminum. The results reveal that direct relationships exist for the plots of: (i) the strain-hardening exponent vs. the post-necking strain and (ii) difference of post-forming strengths vs. the strain-hardening exponent. Furthermore, the post-forming yield strength can be enhanced by 66.9% through the Single Point Incremental Forming (SPIF). Similarly, the ductility can be doubled by conducting the SPIF after performing the annealing of the as-received rolled sheet. In the present study, parts formed at a wall angle (θ) of 40° with a tool diameter (d) of 6 mm exhibit the highest strength. Moreover, most ductile parts will be obtained at ω = 1500 rpm, d = 22 mm and θ = 20°. It has also been shown that the compressive residual stresses are favorable for higher yield strength and improve hardness of the formed parts.

scholarly journals Experimental Determination of Residual Stresses Generated by Single Point Incremental Forming of AlSi10Mg Sheets Produced Using SLM Additive Manufacturing Process

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2542 ◽  
Author(s):  
Cecilio López ◽  
Alex Elías-Zúñiga ◽  
Isaac Jiménez ◽  
Oscar Martínez-Romero ◽  
Héctor. R. Siller ◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Manufacturing Process ◽  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
X Ray Diffraction ◽  
Variable Wall ◽  
Metallic Sample

This paper focuses on investigating the residual stress values associated with a part fabricated by Selective Laser Melting technology (SLM) when this is subjected further to forces on single point incremental forming (SPIF) operation of variable wall angle. The residual stresses induced by the SLM manufacturing process on the fabricated AlSi10Mg metallic sheets, as well as those produced during their forming SPIF operation were determined by X-ray diffraction (XRD) measurements. Significant residual stress levels of variation, positive or negative, along the metallic sample were observed because of the bending effects induced by the SPIF processes. It is also shown how the wall thickness varies along the additive manufactured SPIFed part as well as the morphology of the melting pools as a function of the deformation depth.

scholarly journals Interaction of Process Parameters, Forming Mechanisms, and Residual Stresses in Single Point Incremental Forming

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 656 ◽  
Author(s):  
Fabian Maaß ◽  
Marlon Hahn ◽  
A. Erman Tekkaya
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Stress State ◽  
Residual Stresses ◽  
Process Parameters ◽  
Process Model ◽  
Incremental Forming ◽  
Single Point ◽  
Single Point Incremental Forming ◽  
Residual Stress State

The residual stress state of a sheet metal component manufactured by metal forming has a significant influence on the mechanical properties, and thus determines the time until the component fails, especially for dynamic loads. The origin of the resulting residual stress state of incrementally formed parts with regard to the forming mechanisms of shearing, bending, and the normal stress component is still under investigation. The relationship between the process parameters, the forming mechanisms, and the resulting residual stress state for a complex part geometry manufactured by single point incremental forming (SPIF) is presented in this publication. For this purpose, a validated numerical process model is used to analyze the influence of the step-down increment Δz for truncated cones on the characteristics of the forming mechanisms and the resulting residual stress state. For the first time the forming mechanisms are evaluated numerically on both sides of the formed component. A relationship between the process parameters, forming mechanisms, residual stresses, and the mechanical properties of an incrementally formed component is shown. Shearing-induced hardening is identified as a relevant influence on the residual stress state of cones.

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