Khurram Altaf

Dr. Khurram Altaf

Universiti Teknologi PETRONAS
orcid

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 September 2020 in Polymers
Verified
Journal Article
Open access
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Syed Waqar AhmedSyed Waqar Ahmed
Syed Waqar Ahmed
GHGhulam Hussain
Ghulam Hussain
Khurram AltafKhurram Altaf
Khurram Altaf
Sadaqat AliSadaqat Ali
Sadaqat Ali
MAMohammed Alkahtani
Mohammed Alkahtani
AAAyoub Alzabidi
Ayoub Alzabidi
The scope of additive manufacturing, particularly fused deposition modelling (FDM), can indeed be explored with the fabrication of multi-material composite laminates using this technology. Laminar composite structures made up of two distinct materials, namely acrylonitrile butadiene styrene (ABS) and carbon fiber reinforced polylactic acid (CF-PLA), were produced using the FDM process. The current study analyzes the effect of various printing parameters on the interfacial bond strength (IFBS) of the ABS/CF-PLA laminar composite by employing response surface methodology. The physical examination of the tested specimens revealed two failure modes, where failure mode 1 possessed high IFBS owing to the phenomenon of material patch transfer. Contrarily, failure mode 2 yielded low IFBS, while no patch transfer was observed. The analysis of variance (ANOVA) revealed that printing parameters were highly interactive in nature. After extensive experimentation, it was revealed that good quality of IFBS is attributed to the medium range of printing speed, high infill density, and low layer height. At the same time, a maximum IFBS of 20.5 MPa was achieved. The study presented an empirical relation between printing parameters and IFBS that can help in forecasting IFBS at any given printing parameters. Finally, the optimized printing conditions were also determined with the aim to maximize IFBS.

1 January 2021 in Applied Thermal Engineering
Verified
Journal Article
Closed access
ATAdeel Tariq
Adeel Tariq
Khurram AltafKhurram Altaf
Khurram Altaf
SASyed Waqar Ahmad
Syed Waqar Ahmad
GHGhulam Hussain
Ghulam Hussain
TRT.A.H. Ratlamwala
T.A.H. Ratlamwala

1 July 2016 in Powder Technology
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Journal Article
Closed access
MAMuhammad Aslam
Muhammad Aslam
FAFaiz Ahmad
Faiz Ahmad
PYPuteri Sri Melor Binti Megat Yusoff
Puteri Sri Melor Binti Megat Yusoff
Khurram AltafKhurram Altaf
Khurram Altaf
MOMohd Afian Omar
Mohd Afian Omar
RMRandall M.German
Randall M.German

7 June 2013 in Rapid Prototyping Journal
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Journal Article
Closed access
Khurram AltafKhurram Altaf
Khurram Altaf
ARAhmad Majdi Abdul Rani
Ahmad Majdi Abdul Rani
VRVijay R. Raghavan
Vijay R. Raghavan
Purpose: The purpose of this paper is to present a technique of fabricating profiled conformal cooling channels (PCCC) in an aluminium filled epoxy mould using rapid prototyping (RP) and rapid tooling (RT) techniques and to compare the cooling times for the moulds with circular and profiled channels experimentally. The cooling channels in injection mould tools have a circular cross section. In a PCCC, the cross sectional shape is so designed that the flat face surface of the channel facing the cavity follows the profile of the cavity. These types of channels can be manufactured through RP and RT techniques.Design/methodology/approach: A part to be moulded was designed and modelled. Two moulds were then designed with the part cavity, one having a circular channel and the second with a profiled channel, both having the same cross sectional area for coolant flow. The channel patterns were designed with supports according to their position regarding height and distance from the cavity as designed earlier. Both channels have the same distance from the cavity wall. RP patterns were produced for both channels and part using the Thermojet 3D printer. The cooling channel and the moulded part patterns were then assembled as designed in the moulds. Moulding frames were fabricated with aluminium plates and the pattern was placed in the frames. Epoxy was poured on the pattern and then cured. The moulded part and the channel patterns embedded inside epoxy were melted out during the final curing cycle, leaving behind the circular‐ and profiled‐cooling channels in the moulds. For the cooling time measurement, injection moulding was done with moulds with circular and profiled channels. Moulded part temperature will be recorded by embedding thermocouples within the mould cavities.Findings: A technique for the manufacture of cooling channels of different profiles in epoxy moulds was presented. Experimental analysis for temperature measurement for the moulded part with injection moulding process showed that PCCC mould has less cooling time then mould with circular channels.Research limitations/implications: The technique presented is based on the metal‐filled epoxy materials used in RT and was obtained using a specific test part. Epoxy tooling can be a useful alternative of metallic mould to produce injection mould tools. A limitation for the epoxy moulds is that they have a limited life as compared with metallic moulds.Originality/value: This is a new technique of manufacturing moulds with cooling channels using RP/RT techniques. Moulds with different channel cross sections can be manufactured using this technique.

8 June 2018 in Metals
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Journal Article
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Khurram AltafKhurram Altaf
Khurram Altaf
JQJunaid A. Qayyum
Junaid A. Qayyum
ARAhmad Majdi Abdul Rani
Ahmad Majdi Abdul Rani
FAFaiz Ahmad
Faiz Ahmad
Puteri Sri MelorPuteri Sri Melor
Puteri Sri Melor
RGRandall M. German
Randall M. German
Conventionally, molds for metal injection molding (MIM) process are fabricated using metallic materials using conventional machining processes. Machined metal molds are resilient and therefore could be suitable for mass production of MIM parts. However, with the process of mass production leading to permanent hard tooling, the design is subjected to rigorous testing and iteration before finalization. During design analysis and the iteration process, the demand for MIM parts (part demand) is at low-volume. Therefore, machined metal molds could be costly and time consuming for low volume and customized end-use products. 3D printed molds could be a suitable choice for MIM production for such applications. The present study compares the performance of Fused Deposition Modelling (FDM) 3D printing (3DP) process made polymer molds with an aluminum mold for potential use in MIM process. It was observed that 3DP molds could successfully be used for a limited number of MIM cycles.

11 December 2022 in Applied Sciences
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Journal Article
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HQHamza Qayyum
Hamza Qayyum
GHGhulam Hussain
Ghulam Hussain
MSMuhammad Sulaiman
Muhammad Sulaiman
MHMalik Hassan
Malik Hassan
AAAaqib Ali
Aaqib Ali
Khurram AltafKhurram Altaf
Khurram Altaf
Fused Filament Fabrication (FFF) is a popular additive manufacturing process to produce printed polymer components, whereby their strength is highly dependent on the process parameters. The raster angle and infill pattern are two key process parameters and their effects on flexural properties need further research. Therefore, the present study aimed to print test specimens with varying raster angles and infill patterns to learn their influence on the in-plane and edgewise flexural properties of acrylonitrile–butadiene–styrene (ABS) material. The results revealed that the highest in-plane and edgewise flexural moduli were obtained when printing was performed at 0° raster angle. In comparison, the lowest values were obtained when the printing was executed with a 90° raster angle. Regarding the infill pattern, the tri-hexagon pattern showed the largest in-plane modulus, and the quarter-cubic pattern exhibited the greatest edgewise flexural modulus. However, considering both the modulus and load carrying capacity, the quarter-cubic pattern showed satisfactory performance in both planes. Furthermore, scanning electron microscopy was used to investigate the failure modes, i.e., raster rupture, delamination of successive layers and void formation. The failure occurred either due to one or a combination of these modes.