Mechanical and Machinability characteristics of Al ...

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Mechanical and Machinability characteristics of Al–NiTi composites reinforced with SiC particulates. Rajesh Shanmugavel1 & Purusothaman Mokkandi1 ...
J Aust Ceram Soc DOI 10.1007/s41779-017-0023-0

RESEARCH

Mechanical and Machinability characteristics of Al–NiTi composites reinforced with SiC particulates Rajesh Shanmugavel 1 & Purusothaman Mokkandi 1 & Manivannan Jayamani 1 & N. Rajini 1 & M. Uthayakumar 1 & S. Thirumalaikumaran 2

Received: 11 December 2016 / Accepted: 17 January 2017 # Australian Ceramic Society 2017

Abstract This paper discusses the effect of the addition of SiC in Al–NiTi composites on hardness and compression of the composites. The addition of SiC in the Al–NiTi composites significantly increases the hardness and compression strength. In addition to the mechanical properties, it also discusses the effect of abrasive water jet pressure, standoff distance, and feed rate during machining of the Al–NiTi–SiC composites. The surface roughness and kerf angle are considered as the output quality characteristics. Experiments are conducted based on L9 orthogonal array. The Techniques for Order of Preference by Similarity to Ideal Solution (TOPSIS) with entropy method is used to accomplish the objective of the experimental study. Entropy is a method used to compute the weight factor for each of the output performance characteristics. TOPSIS with entropy reveals that the optimal

* Rajesh Shanmugavel [email protected] Purusothaman Mokkandi [email protected] Manivannan Jayamani [email protected] N. Rajini [email protected] M. Uthayakumar [email protected] S. Thirumalaikumaran [email protected] 1

Department of Mechanical Engineering, Kalasalingam University, Virudhunagar, India

2

School of Mechanical Engineering, Yeungnam University, Gyeongsan, South Korea

combination of the machining parameters for the multiperformance characteristics of Al–NiTi–SiC reinforced hybrid is set at a pressure of 225 MPa, standoff distance of 2, feed rate 40 mm/s, and weight percent of reinforcement 3%. The optimal results were compared with the experimental results for verifying the approach, and it is observed that the surface roughness decreases from 4.03 to 3.46 μm, and kerf angle decreases from 16.32 to 14.71. Keywords Al–NiTi–SiC hybrid composites . AWJ . TOPSIS . Surface roughness . Kerf angle

Introduction The need for light and special functional characteristic materials are increasing day by day to meet the requirement of automobile, aerospace, electronics, and biomedical industries. Strength and stiffness of the materials decides the load-bearing capacity of the materials. The increase in strength and stiffness of the composites can be obtained through the technological development in the area of metal matrix composites [1]. Among the different metal matrix composites, aluminumbased metal matrix composites play a significant role in the automobile and aerospace industries because of its low density, thermal characteristics, and easiness of the fabrication process. In aluminum metal matrix composites, the reinforcements are used in the form of long, short fiber and particulates, most of these reinforcements are ceramic materials such as SiC, B4C, and Al2O3. The addition of these reinforcements in the aluminum and its alloys increases the strength, Young’s modulus, and stiffness of the composite materials [2]. Recently, the NiTi could be effectively used as reinforcement to obtain better mechanical and functional properties in aluminum-based composite materials. The uniqueness of the

J Aust Ceram Soc

NiTi material is capable of recovering its original shape after deformation has occurred. For this reason, the applications of NiTi are finding attention and interest in a wide range of applications [3]. Therefore, NiTi could be considered as an alternate reinforcement material to enhance the mechanical properties without losing its shape memory effect. Addition of ceramic reinforcement affects the tensile and impact properties of the composites because of its poor coefficient of thermal expansion (CTE), since most of the ceramic reinforcements are having lower CTE than matrix materials. These crises can be benefitted by the addition of NiTi, because of its high coefficient of thermal expansion by which it is possible to obtain good fracture toughness and tensile strength [4]. It is evident from the experimental results of Dixit et al. [5] that addition of NiTi in the aluminum matrix improves the mechanical properties, and the increase in the property is attributed by the induced compressive and tensile stress of NiTi particles [5]. Xie et al. [6] fabricated NiTi fiber-reinforced Al 6061 composites and investigated the effect of prestrain on yield strength of the composites. It is found that an increase in prestrain increases the yield strength of the composites [6]. In fact, different methods are available for the fabrication shape memory alloy (SMA) composites which mainly include casting, hot pressing, ultrasonic consolidations, and powder metallurgy process. Every fabrication has its own advantage and disadvantage; in the case of powder metallurgy process, it could be possible to get homogenous distribution of reinforcement particle on the matrix material; another advantage is the ability to produce high volume of products with low cost. Powder metallurgy could be the most suitable process for the fabrication of aluminum-based composites, using NiTi particle as reinforcement [7]. Ahn et al. [8] developed NiTi-based aluminum reinforced composites; it is worthy to note that shortening the sintering duration affects the diffusion process and bonding between the matrix and reinforcement materials [8]. Thorat et al. [9] developed NiTi/2124 aluminum composites; it is found that lowering and rising the sintering temperature initiate the formation of interface products which affects the binding characteristics of the matrix and reinforcement materials. It is also observed that addition of NiTi reinforcement increases the damping capacity of the fabricated composites [9]. Miranda et al. [10] studied the effect of sintering stage in NiTi short fiberreinforced aluminum composites; it is found that increasing the sintering stage reduced the shear strength of the composites [10]. Porter et al. [3] developed 10% vol. NiTi particulatereinforced aluminum metal matrix composites, experimental results revealed that addition of NiTi increases the fatigue property [3]. Akalin et al. [11] developed Al–NiTi composites and NiTi–SiC–Al hybrid composites; the result of dry sliding wear test reveals that transverse fiber orientation shows mostly

abrasive wear whereas monolithic and lateral fiber orientations show adhesive wear mechanism. The hybrid composites show that addition of SiC increases the wear resistance of the composites [11]. Şahin et al. [12] studied the effect of nano alumina oxide on the wear behavior of Al–NiTi composites, it is found that addition of nanoalumina oxide reduces the wear rate and increases the hardness of the composites. It is also observed that addition of nanoalumina oxide increases the corrosion resistance property of the composites [12]. In mechanical and metallurgical points of view, these NiTi and NiTi composites possess good characteristics. Though, there are processes which could fabricate the composites near net shape, even though machining process must be employed to get the desired dimensional tolerance and surface texture and accuracy. Lin et al. [13] made an attempt to study the machinability of NiTi shape memory alloy and found that presence of intermetallic compounds makes machining process difficult and leads poor surface texture and strain hardening effect in the shape memory alloy [13]. Arola and Mccain [14] applied abrasive water jet peeing hybrid machining method to create the required surface texture using controlled hydrodynamic erosion in Ti6Al4V metal orthopedic implants [14]. Kong et al. [15] adopted two different approaches to machine the NiTi shape memory alloy materials; it is found from the experimentation that abrasive water jet machining is much better than the plain water jet machining with respect to more controllable depth and surface texture [15]. Frotscher et al. [16] machined the NiTi sheets using two different machining processes; it is observed that abrasive water jet machining is the most suitable process than micromachining process to reduce the thermal influence and cutting time of the machining process [16]. The other unconventional machining process like EDM, WEDM, and Laser beam could be employed to machine the NiTi materials, but these processes are cursed with recast layer, heat affected zone, and microvoids [17]. The aim of the present study is to study the effect of water jet machining parameters on the surface roughness and kerf angle of the composites.

Methods and procedure Commercially available elemental powders aluminum, titanium (Oxford Laboratory,