Slope Casting Process: A Review

Abstract

Semi solid processing is a near net shape casting process and one of the promising techniques to obtain dendritic free structure of metals. Semi solid casting gives numerous advantages than solid processing and liquid processing. Semi solid casting process gives, Laminar flow filling of die without turbulence, Lower metal temperature, Less shrinkage, Less porosity, Higher mechanical properties. Semi solid casting process is industrially successful, producing a variety of products with good quality. Slope Casting process is a simple technique to produce semi solid feed-stoke with globular microstructure and dendrite free structure castings. Slope casting process depends on different process parameters like slope length, slope angle, pouring temperature etc. The present study mainly focuses on review of various explorations made by researchers with different process parameters of the Slope casting process and explain the mechanisms that lead to microstructural changes which leads to good mechanical properties.

1. Introduction

Semi-solid processing as the name suggests is the processing of non-dendritic material between its liquidus and solidus temperatures. In recent years, much work has been conducted in exploring this field with respect to understanding the mechanisms involved. The inherent properties of semi-solid materials at the semi-solid processing temperature such as lower heat content, relatively higher viscosity comparable to liquids and low flow stresses, enables the semi-solid process to show distinct advantages over fully liquid and/or fully solid-state processes. Some of the important benefits of this technique are low mold erosion, low energy consumption, improved die filling, less gas entrapment, lower solidification shrinkage, reduced macro-segregation and fine microstructure. Therefore, this process is rapidly gaining commercial importance [1, 2, 3]; A non-dendritic microstructure can be obtained by stirring, either mechanically or electro-magnetically; grain refining; low superheat melt processing; solid state mechanical treatment and reheating [4, 5, 6, 7]; The manufacturing industries widely focused on the semi solid routes to produce components with superior mechanical and metallurgical properties. Slope casting process is one of the simplest techniques to produce semi solid slurry [8]. Slope cating process is pouring of molten metal through a slope channel into a mold. This slope channel help as a site for nucleation and fragmentation of dendrites due to shearing force between different layers of flowing stream [9]. Slope casting process depends on different process parameters like slope length, slope angle, pouring temperature etc. [10, 11, 12, 13, 14]. In recent years Aluminum alloys are using mostly in the automotive industries. Among the Aluminum alloys, the Al-Si alloys have good casting characteristics like high fluidity and good cast-ability which makes them advantageous for both small and complicated castings. Every year lakhs of Aluminum alloy components are produced through semi solid processing route. The present study mainly focuses on review of various explorations made by researchers with different process parameters of the Slope casting process and explain the mechanisms that lead to microstructural changes which leads to good mechanical properties.

2. Semi-solid casting

The processing of alloy between liquidus and solidus (mushy zone) range is known as the semi solid process, it was first discovered in 1970s, by spancer at Massachusetts Institute of Technology (MIT); found that at semi solid range of alloy behaves thixotropically (Decreases in viscosity if it is sheared but it will thicken again if it is allowed to stand)and by applying continuous stirring on the semi solid state produced no dendritic and spheroidal microstructure [15, 16, 17, 18, 19]. The semi solid casting route gives enormous advantages like dendritic free structure leads to globular structure as seen in Figure 1, less defects such as porosity, shrinkage, gas entrapment and macro-segregation. Better advantages than conventional casting that superior quality, low forming temperature, superior mechanical properties with microstructural refinement. The semi-solid process results in a non-dendritic microstructure due to forming at a temperature between solidus and liquidus temperature as shown in phase diagram, Figure 2. In semi solid process, temperature has a pivotal role on the resultant microstructure like orientation of grain, morphology of grain during solidification of alloys [22, 23, 24]. Semi-solid processing is used for all the shape forming processes which take advantage of the semi-solid range of the alloys for processing. Rheology and Thixotropy, two basic phenomena play a major role, In semi-solid processing. The apparent viscosity of a material in the liquid state varies with change in shear rate In Rheology. This gives the liquid like slurry to be processed even at sufficiently high solid fraction [25]. Thixotropy, is the ability of a material to Decreases in viscosity if it is sheared but it will thicken again if it is allowed to stand [26]; A material with a non-dendritic structure is the best suitable material for semi-solid processing. it is believed that, in the semi-solid state, the non-dendritic equiaxed grains easily slide/glide on each other on the application of a shear force [27].

Figure 1.

Using semi solid process technique dendritic structure changes to globular [20].

Figure 2.

Phase diagram of Al-Si alloy [21].

Thixotropy behavior can be define as when the material state is partially solid with 40–50% solid fraction and is sheared applied by external force, then its viscosity will decrease due to the break/detachment of the coalescence material, and it will flow like a liquid, for a certain time if it is allowed to stand, equiaxed coalescence will increase the viscosity of the material, by that it being able to support its own weight in the same way as if it was solid [28].

2.1 The mechanism of non-dendritic structure

To describe mechanism for non-dendritic structure in semi solid process many theories have been proposed. These mechanisms include dendrite arm fragmentation, dendrite arm root re-melting, and growth control mechanism. Hv Atikson et al. [20], Vogel et al. [29]; proposed that under shearing forces dendrite arms bends due to its plasticity, which introduce large misorientations inside the dendrite arms and dislocations introduced; rearrangements of dislocations occur to form grain boundaries at the melting temperature. The energy of the grain boundaries becomes more than twice the liquid/solid interfacial energy when the misorientations between grain boundaries are more than 20°, then separation of the dendritic arms observes due to wetting of the grain boundaries by liquid metal. Schematically illustrated in Figure 3.

Figure 3.

Schematic illustration of the steps of the mechanism of dendrite fragmentation: (a) undeformed dendrite; (b) after bending; (c) formation of high-angle boundary; and (d) fragmentation through wetting of grain boundary by liquid metal [22].

Hellawell et al. [30]; proposed grain multiplication theory, Thermal convention and shearing force have a direct effect at the roots of secondary dendrite arms, melting off rather than breaking off secondary arms observed, and grain multiplication, schematically illustrated in Figure 4. Evolution of structure during solidification with shear force depends on the cooling rate and shear rate, with increase in shear and cooling rate gives non dendritic/globular structure that that the particle shape and size vary irreversibly with shear and colling rate. Illustrate in Figure 5.

Figure 4.

Schematic diagram of dendrite multiplication theory [22].

Figure 5.

Evolution of structure during solidification with shear force: (a) initial dendritic fragment; (b) dendritic growth; (c) rosette; (d) ripened rosette; and (e) spheroid [20].

2.2 Classification of semi solid process

The semi solid casting process mainly classified into the thixo casting and rheo casting and these processes are farther divided into many process techniques show in below (Figure 6).

Figure 6.

Classification of semi solid processes [31].

2.2.1 Thixo casting

Thixo casting mainly consists of three separate stages the production of a pre-cast billet having the special equiaxed microstructure, the re heating of these billets to the semi-solid temperature and the casting of the components 3. Illustrated in Figure 7.

1. feedstock preparation;

2. Reheating of the billet; and

3. The casting process.

Figure 7.

Thixo casting and thixo forging [2].

2.2.2 Rheo-casting

Rheo-casting is single step process to produce semi solid alloy start with liquid alloy, introduced directly into a mold without any intermediate solidification step. The semisolid slurry produced by means of different process like slope casting, new rheo casting etc. and directly introduced into a die. While thixo-forming is a route consists of reheating and forming process (Figure 8).

Figure 8.

Rheo casting process [2].

3. Slope casting process

Slope casting process is a rheo casting process used for the produce semi solid slurry, it consists with simple equipment and operation technique, the process carried out by pouring molten metal through channel with certain angle into a die where subsequent solidification takes place [32]. The solidification of molten alloy along a slope channel involves heat transfer, fluid flow, adhesion behavior. When the molten metal flowing through the slope channel with an angle and length [33, 34, 35, 36, 37], heat transfer takes between the slope channel wall and melt in contact, where generation of nuclei takes places, due to the effect of gravitation force and flow of stream the nuclei produced on slope wall are detached from the slope plate and subsequently flow through the melt stream, solid fraction of metal(semi solid slurry) observed at end of slope channel [38, 39, 40, 41, 42]. shear stress acting on the slurry layers and melt flow inertia restricted dendritic growth usually observed in conventional casting alloys. Illustrated in Figure 9. Slope casting process is a simple technique, but it can be prone to gas pick up and oxide formation which will impact negatively on mechanical properties [44, 45].

Figure 9.

Line illustration of slope casting process [43].

3.1 Mechanisms involved in slope casting process

Two mechanisms have been suggested to explain the formation of non-dendritic microstructure during flow along slope casting process. According to Haga and Kapranos et al. [46, 47], dendritic fragmentation mechanism plays an important role in slope casting process during microstructural evolution. The fragmentation of weak dendritic arms observed when the partially solidified melt collides under gravitational forces on the inclined/slope channel. Motegi et al. [48] proposed, crystal separation theory, where granular crystals nucleate and grow on the slope wall and are washed away from the wall by fluid motion illustrated in Figure 10.

Figure 10.

Crystal separation theory (a). The generation of nuclei at slope plate wall (b). Segregation of granular crystal (c) flow through the melt [30].

The shear force is main factor for dendritic arm fragmentation but its effect is related to the velocity boundary layer [21] as shown in Figure 11.

Figure 11.

Schematic diagram of the shear stress variation and velocity distribution inside the boundary layer during the flow of melt in cooling slope casting process [38].

3.2 Parameters effect the slope casting process

The process parameters in the slope casting of semisolid slurry preparation are [21, 31, 43, 44, 45, 46, 47, 48, 49]:

• Pouring temperature,

• Slope angle,

• Slope length,

• Slope plate temperature,

• Vibration of slope,

• Mold vibration etc.

3.2.1 Effect of pouring temperature

It is the most influencing parameter in slope casting process, T hogo et al. [36] investigated the effect of melt temperature and mold material found that pouring temperature have the great effect on the microstructure and it accounts nearly 35% of the total effect. Y Birol et al. [37] investigated the effect of pouring temperature and slope length, reported that the melt superheat required longer cooling lengths for higher pouring temperatures. Pouring with lower temperature causes formation of solid shell (formation of a thin layer of metal due to the primary nuclei that stick to the slope channel that reduces the effectiveness of the slope channel in generating nuclei) and pouring with the super-heated temperature may not get sufficient time to cool to range to produce solid nuclei on the slope plate, the main reason is that each parameter corelate each. Similar observation reported by Wen Liu et al. [39], if pouring temperature is too high a small number of primary α-aluminum phase will precipitate and some coarse primary α-aluminum phase. If the pouring temperature is too low the melt will cool rapidly and solidify. P. das et al., the temperature of the cooling plate has no prominent effect on microstructure, nevertheless a slurry with approximately 10% fraction solid can easily be obtained at the end of the plate.

3.2.2 Effect of slope length

Most of studies, slope length ranges from 200 to 800 mm, H. bidhiman et al. [41]. reported that increase in slope length that means melt flow time through channel increases it may cause the temperature drop and formation of the oxidation and solid shell as we above discussed it causes decrease in rate of heat transfer which leads to the decrease of the nucleation rate of primary solid phase, too short length does not give the proper nuclei formation and the time for the dendritic fragmentation. Slope length and slope angle are interrelated. If slope angle high need slope length should be more otherwise melt does not get sufficient time for shearing. The slope length effect on final microstructure accounts nearly 30% from studies. P. das et al. [40].

3.2.3 Effect of the slope angle

Most studies the angle ranges from 15 to 60°, the small angle is unable to give the melt to flow and shear effect on the slope plate will be less and the higher angle may cause the high velocity which does not give time to melt formation semi solid slurry and dendritic fragmentation. Farshid Taghavi and Ghassemi [42] reported the angle of slope channel had remarkable effects on the size and morphology of α-Al phase. By increasing the angle of the slope channel, the effect of shear stress and the rate of heat transfer increase. As a result, more solid particles are detached from the layer of slope channel. On the other part, duration time of shear stress and heat transfer between the melt and surface of inclined plate decrease by increase in the angle. As we above discussed in 3.2.2. the slope length and slope angle corelated to each other.

3.2.4 Effect of the slope vibration

Very few studies on effect of vibration slope on microstructural changes. Slope vibration frequency ranges from 10 to 60 Hz. Studies by Shaya Safari et al. [44], Wen Liu et al. [39] conclude that There was no solid shell formation on the surface of slope channel by using slope vibration. The combine effect of vibration and slope channel causes increase in the amount of nucleation and nuclei due to uniform cooling rate. The mechanism in vibration slope channel is proposed that vibrating force and gravity result in Bending stress introduced in between the growing dendritic and liquid. Because of the viscous resistance of liquid, with respect to the dendritic particles and liquid phase there is a difference of the transport velocity, which causes crash among the grains and the scrub of the liquid on dendritic particles. The weak dendrite arms breakoff and form fine grains. Vibration helps the heat transfer mechanism in possible direction. The stirring caused by vibration gives rise to local temperature fluctuation of liquid phase around the primary α-al phase and Re melting of dendritic arms at the necks occurs. Which favorable to form short and homogenous small primary dendrites, equiaxed and rosette non dendritic grains.

3.2.5 Heat treatment by reheating

Researchers extended work on Slope casting process by subsequent heat treatment of casts after slope casting for better mechanical properties through spheroidization of grains and removal of defects like internal stress and porosity. Yucel Birol et al. [37] worked on the cooling slope casting and thixo forming of hypereutectic A390 alloy. Reported that The thixoformed part after slope casting process was metallurgically sound, free from porosity and revealed a uniform dispersion of fine Si particles in a homogeneous matrix. Increase mechanical properties observed. Nursen Saklakoglu et al. [33]: investigated on the microstructural evolution of ETIAL 160 aluminum feed stock produced by the cooling slope casting process experiments done with pouring temperatures of 605 and 615°C respectively subsequent isotheral heating at 565°C at 5 and 10 mins respectively, slope casting process results the primary α-aluminum dendrites has changed into α-aluminum rosette. Subsequent heat treatment helps to modify the rosette to globular structure. P das et al. [40]; too long a heating time will cause structural coarsening, while too short a heating time will lead to incomplete spheroidization of solid particles. Thus, there is a need to get optimum reheating parameters of the semi-solid alloys processed via slope casting.

3.3 Composites by slope casting

Composite materials produced using slope casting technique were reported by researchers. P. Das, [40] has studied about the semi solid microstructure of Mg₂ Si/Al composite by cooling slope casting process, reported that, the morphology of primary Mg₂Si obtained non-dendritic and size of α Al was changed to 10 from 200 μm, Toshio Haga et al. [36]. Reported that slope casting has a significant influence on the shape and grain morphology of the Metal matrix composites (MMCs). The properties of the MMCs produced by slope casting were found to be higher than those of the MMCs produced by using conventional stirring.

Distinguished the literature into table according to the optimum process parameters used in Slope Casting Process of Semi-Solid Alloys and Composites shown inTable 1 and post parameters in Table 2.

Author & year	Alloy	Process parameters
		Length of slope in (mm)	Slope angle in (degrees)	Pouring temperature in (centi grade)	Slope material, coating material and cooling medium	Slope vibration in (Hz)	Mold vibration in (Hz)	Mold material
S. R. Mukkollu et al. (2020) [43]	Al-4%cu-2%mg alloy	500	30	X	Mild steel	X	20(ultrasonic)	steel
Kerem Altug Guler et al. (2019) [35]	AA7075	650	30 & 60	660	Copper plate	X	X	Steel
N. K. Kund (2019) [21]	A356	—	—	—	—	—	—	Steel
Sahaya Safari et al. (2018)[44]	AlMg2Si	400	45	880	Copper plate, boron nitride and water	40	X	Cast-iron
Adnan Mehmood, et al., (2016) [50]	A356	800	15, 30, 45, 60 &75	800	Stainless steel and oil	×	×	Stainless steel
S. Deepak Kumar, et al. (2015) [51]	A356& A356–5TiB2	×	60	650	Mild steel and water inside	x	x	Mild steel
S. DeepakKumar et al. (2015) [52]	Al-7Si alloy	400	15, 30, 45 and 60	630, 640 and 650	water	X	X	Mild steel
Amir. A. Abdelsalam, et al. (2015) [53]	A356/Al2O3	500	60	X	low carbon steel, hard chrome and water	X	X	Steel
Saffari, et al. (2015) [54]	Al-Mg2Si	1000	45	X	Copper plate and boron nitride	40	X	X
S. Deepak Kumar, et al. (2015) [55]	A356 and A356-5TiB2	400	60	640	Mild steel & water	X	X	Mild steel
S. Deepakkumar, et al. (2014) [32]	A356 alloy	400	60	640	zirconia, and water	X	X	Mild steel
Amitesh Kumar, et al. (2014) [56]	High chromium cast iron	1000	15	X	Mild steel coated with graphite	X	X	Sand
Prosenjit Das, et al. (2014) [57]	A356 alloy	500	30, 60 and 45	X	Stainless steel, boron nitride and oil	X	X	Mild steel
Hamed Khosravi, et al. (2013) [58]	A356 alloy	100, 300 and 500	30, 45 and 60	660, 680 and 700	Boron nitride	X	X	Mild steel
K. S. Alhawari. (2013) [28]	A356 and Al2O3	300	60	650	Steel, boron nitride	X	X	Steel
P. Das, et al. (2013) [59]	A356 alloy	—	60 and 45	—	Boron nitride	X	X	Steel
R. Ritwik, et al. (2013) [60]	AlSi7Mg alloy	—	10	—	—	X	X	Steel
Prosenjit Das et al. (2012) [40]	A356	X	60, 45	925	Oil, boron nitride coating	X	X	Mild steel
N. Saklakoglu (2011) [34]	A380	350	60	615, 630, 650	water cooled, boron nitride	X	X	Steel
Zongning Chen (2011) [26]	Al-12Si and K2 TiF6 and KBF4	X	X	650	Water cooled	X	X	Copper
Wen Liu et al. (2011) [39]	ZAlSi9Mg	400–900	60	590–620	Copper plate and water	0–50 Hz	X	X
Jun X et al. (2011) [45]	A356 alloy	300, 500, 700	30, 45, 60	650, 670, 690	Mild steel and water cooled	X	X	X
H. Budiman et al. (2011) [61]	A356 alloy	250	60	610–630.	Mild steel, boron nitride	X	X	Steel
T. Haga et al. (2010) [62]	A356	30, 50, 100, 200 and 300.	15, 30, 45 and 60	620	Mild steel. Coated with BN	X	X	Steel
S. Gencalp Saklakoglu (2010) [63]	A380 alloy	500	60	630	Mild steel. Coated with BN	5.75 Hz.	X	Steel
W. Wierzchowski et al. (2010) [64]	hypoeutectic gray cast iron and high-chromium cast iron	600	0–15	TP = TL + 20 K	Copper plate, boron nitride	X	X	X
Farshid Taghavi and Ghassemi (2009) [42]	A356 alloy	20, 40, 60	20, 30, 40, 50, 60	680	Copper plate	X	X	Steel
H. Budiman et al. (2009) [41]	Al-Si alloy	250	60	620	Mild steel, boron nitride and water	X	X	Steel
Nursen Saklakoglu (2008) [33]	ETIAL 160	300	60	605, 615	Steel Plate Coated With BN And water	X	X	Steel
Yucel Birol (2008) [17]	A390 alloy	500	60	—	Steel plate and water cooled	X	X	Steel
Q. D. Qin and Zhao, (2007) [27]	Al/mg2Si composite	X	X	X	Alumium plate	X	X	Steel
E. Cardoso Legoretta et al. (2008) [65]	A356 alloy	150, 200	45, 60	+20 K–30 K	Mild steel coated with boron nitride and Cold water	X	X	Satinless steel
Yucel Birol (2007) [17]	A357 alloy	200, 300, 400	60	620–640	Steel plate coated with the boron nitride and water	X	X	Mild steel
Alex Muumbo et al. (2003) [66]	Cast iron	—	5–15	+20 k	Boron nitride coated	X	X	Mild, graphite, sand
Tetsuchi Motegi (2002) [48]	Al-Si-Mg alloy	80, 160, 200, 240	40, 60, 80	656, 666, 676, 686, 696	Copper plate	X	X	X
Toshio Haga (2002) [67]	A356	300	60	602, 630, 650	Mild steel coated with BN	X	X	X
Toshi Haga (2001) [36]	Al-6 Si	300	60	600	Mild steel coated with BN	X	X	Mild steel with out insulator and with insulator

Table 1.

Process parameters.

Author & year	Tensile test	Hardness	Grain size & shape factor	Findings
S. R. Mukkollu et al. (2020) [43]	x	✓	x	Refined microstructure can be obtained by if cooling slope integrated with ultrasonic acoustic cavitation.
Kerem Altug Guler et al. (2019) [35]	✓	✓	✓	Castings with the slope angle of 60 are superior to 30.
N. K. Kund (2019) [21]	✓	✓	✓	Cooling slope leads to globular and non-dendritic microstructure.
Sahaya Safari (2018) [44]	✓	✓	✓	The hardness, values of the as-cast VCS sample are higher than those of its CS
Adnan Mehmood, et al., (2016) [50]	✓	X	✓	Tensile and hardness are highest at the sloping plate at the angle of 600
S. Deepak Kumar et al. (2015) [51]	X	✓	✓	A cooling slope length of 400 mm, a low cooling slope angle of 150 was effective in dendrite fragmentation
Amir. A. Abdelsalam, et al. (2015) [53]	X	X	✓	Stir casting and cooling slope casting (SC/CSC) exhibited higher Porosity and water-cooling using SC/CSC technique effect the average size of the α-Al grains.
S. Deepak Kumar, et al. (2014) [32]	—	✓	—	Pouring temperature, which accounts for 42.08% of the total effect, followed by cooling length 40.4% and slope angle 17.44% respectively.
K. S. Alhawari. et al. (2013) [28]	—	✓	—	The hardness and wear resistance of the MMC s produced by cooling slope casting were found to be higher those of MMCs produced by using conventional stirring.
R. Ritwik, et al. (2013) [60]	—	—	—	The spheroidization effect of the alpha aluminum dendrites increases with the increase in the angle of inclination.
Prosenjit Das, et al. (2012) [40]	—	—	✓	925 K pouring temperature, 60 slope angle, 500 mm cooling length and wall temperature of 333 K has been identified as the ideal processing condition, which is in good correlation with the numerical findings
Prosenjit Das et al. (2012) [40]	X	X	✓	Spheroids and rosettes of primary Al phase has been obtained through the angle 600
N. Saklakoglu (2011) [34]	X	X	Wear test conducted.	Cooling slope does not given substantial changes in friction characteristics compared to gravity casting, isothermal treatment reduced after cooling slope casting decreased the friction.
Zongning Chen (2011) [26]	✓	✓	✓	The grain size of alpha aluminum phase can be globularized using the cooling slope
Wen Liu et al. (2011) [39]	X	X	✓	Vibration effects the nucleation by increase the pressure subsequently temperature and the dendritic arms are sheared due to the vibration.
Jun X et al. (2011) [45]	X	X	X	Optimum globular microstructure with uniform distribution of A356 alloy is obtained with slope angle 45, plate length 500 mm and pouring temperature 650
H. Budiman et al. (2011) [41]	X	X	✓	The cooling slope casting produced smaller equiaxed α-aluminum grains with better shape factor than the conventional stirring.
T. Haga et al. (2010) [62]	X	X	X	The cooling distance affects the cooling of the melt and adhesion of solidified metal. The melt temperature becomes lower as distance becomes longer. The adhesion of the solidified metal occurs when the cooling distance becomes longer than the suitable distance.
Farshid Taghavi and Ghassemi (2009) [42]	X	X	✓	The refined and globular microstructure with a uniform reproductive distribution of A356 was obtained at an angle of 40 and a length of 40 cm
H. Budiman et al. (2009) [41]	X	X	✓	The water circulation influence on volume fraction liquid/solid grain size and shape factor.
Nursen Saklakoglu (2008) [33]	X	X	✓	Pouring at 300 mm at slope of 60 yielded more globular grains than that obtained with CS
Q. D. Qin and Zhao, (2007) [27]	X	X	✓	with increase in the isothermal holding time from 30 to 600 min the mean size of alpha-aluminum grains increases and its morphology becomes more globular
E. Cardoso Legoretta et al.(2008) [65]	X	X	X	Most of the nucleation has occurred in the upper part of the slope, the area of the impact zone plays an important role in determine the resulting microstructure and that this dominate over the cooling length
Yucel Birol (2007) [17]	X	X	X	The dissipation of the melt superheat required longer cooling lengths for higher pouring temperatures.

Table 2.

Post process parameters.

4. Conclusions

A considerable review of the literature on slope casting of semisolid Aluminum alloys suggest the following:

1. The slope casting process is a simple and cost-effective way of producing feed stock material (non-dendritic or globular) microstructure.

2. slope casting process mainly depends on the process parameters like slope length, slope angle which mainly controls the shear force on metal flow subsequently the better morphology structure obtained.

3. Reheating and isothermal holding temperature after slope casting observed better mechanical properties from different studies.

4. Using slope casting process feed stock material produced with globular microstructure is not only in cast aluminum alloys but also in aluminum metal matrix composites.

5. slope casting is best and simple process to produce the semi solid material and by using subsequent process after slope casting technique can play a prominent role in foundry industries.

6. Due to vibration on slope plate, multiple nucleations and dendritic fragmentation occur which leads to spheroidization.