Boonrat Lohwongwatana

Boonrat Lohwongwatana
Chulalongkorn University · Department of Metallurgical Engineering

PhD in Materials Science

About

52
Publications
15,740
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1,048
Citations
Introduction
Boonrat Lohwongwatana is currently the Director of Biomedical Engineering Research Center at Chulalongkorn University, Bangkok, THAILAND. He holds an Associate Professor position at the Metallurgical Engineering Department, Chulalongkorn University. His expertise includes precision manufacturing, 3D printing of titanium, biomechanical designs and standardized testings conforming to ISO 13485 and ASTM standards.
Additional affiliations
July 2013 - present
Chulalongkorn University
Position
  • Research Assistant
May 2012 - May 2013
Chulalongkorn University
Position
  • Deputy Head of Department
September 2000 - May 2007
California Institute of Technology
Position
  • Research Assistant

Publications

Publications (52)
Article
Full-text available
In this study, a new toxic-free Ti40Zr10Co36Pd14 amorphous alloy with a critical casting size of 5 mm diameter and 20 mm long has been synthesised through copper-mold casting process. The Ti40Zr10Co36Pd14 bulk metallic glass (BMG) rod has further formed into thin films through the filtered cathodic vacuum arc (FCVA) deposition process. To assess th...
Article
Full-text available
Complex orbital fractures, including orbital rims and walls, require precise reconstruction. A titanium-based patient-specific implant (PSI) benefits over other implants when challenged with narrow surgical space and designable implant fixation point. Methods: This is a prospective noncomparative case series to evaluate the effect of complex orbi...
Article
Full-text available
The aim of this study is to synthesize Titania nanotubes (TNTs) on the 3D-printed Ti-6Al-4V surface and investigate the loading of antibacterial vancomycin drug dose of 200 ppm for local drug treatment application for 24 h. The antibacterial drug release from synthesized nanotubes evaluated via the chemical surface measurement and the linear fittin...
Article
In this work, Nile tilapia (Oreochromis niloticus) bone was calcined at 800 °C for 5 h in an air atmosphere to obtain hydroxyapatite powder (FB powder). The elemental composition, phase structure, and morphology of the FB powder were investigated and compared with commercial hydroxyapatite powder (SM powder). The FB-powder exhibited 1.01 at. % of M...
Article
Typical 3D-printing processes involve rapid cooling steps that significantly affect the mechanical behavior of printed Ti-6Al-4V alloys. In this study, the 3D-printing technique was used to fabricate Ti-6Al-4V parts, as is customary of bone implants; subsequently, the parts were heat-treated to improve the mechanical properties and the adhesion of...
Article
Full-text available
Background: Recently, medical three-dimensional printing technology (3DPT) has demonstrated potential benefits for the treatment of cubitus varus deformity (CVD) by improving accuracy of the osteotomy through the use of an osteotomy guide, with or without a patient-mated plate. Here, we present an interesting CVD case, involving a patient who was...
Article
This study aims to evaluate the mechanical performance of custom 3D-printed titanium plates in the treatment of distal humerus fractures. Rigidity of four plating configurations were investigated by finite element analysis. The results reveal that implementation of custom designs with minimal screw holes, lateral-medial linking screw and lateral br...
Preprint
Full-text available
Background Cubitus varus deformity (CVD), a common complication after a supracondylar fracture of the distal humerus, is usually treated with corrective osteotomy. However, due to the complex anatomy of the distal humerus, conventional osteotomy techniques are sometimes unreliable and can result in an inaccurate correction, residual deformity, and...
Article
Full-text available
Introduction The majority of patients with bone sarcoma or an aggressive benign tumor of the toe can be successfully treated by amputation. However, limb-salvage surgery for toe tumors remains challenging. Presentation of case A 26-year-old female presented with an enlarging mass on her right 5th toe. Imaging studies revealed an expansile osteolyt...
Article
Full-text available
In titanium casting, a reaction byproduct known as alpha-case is a hard and brittle phase layer that exists on the surface of cast objects. This reaction layer may be detrimental to the mechanical properties of cast objects and may complicate the finishing processes. To investigate the formation of the alpha-case layer during the casting of commerc...
Article
Full-text available
Background: Midshaft clavicular fractures are common fractures and generally treated conservatively. Among the surgical options, plate fixation is the most popular and has been biomechanically and clinically proven in numerous studies. However, implant failures caused by plate deformations or breakage still occur in up to 16.7% of cases, and recen...
Article
Full-text available
Titanium grade 5 (Ti6Al4V) is a modern material that can be found in a wide spectrum of applications, from medicine to aircraft industry. The commercial alloy is a mix of a body centered cubic structure (BCC_A2) and a hexagonal closed packed structure (HCP_A3). It is obvious, that heat treatment of the alloy will change a ratio between BCC_A2 and H...
Article
Full-text available
Purpose:: Following the radial head replacement, the surface mismatches between the implants and the morphological characteristics of the original proximal radius decreased contact areas and increased contact forces which is potential for the long-term articulating cartilage wear. Several studies demonstrated that the individualized prosthesis, cr...
Article
Full-text available
Successful treatment of the chronic persistent elbow instability is a challenge for orthopedic surgeons. In this form, it is important to recognize and restore the osseous stabilizer in order to obtain the concentric reduction. In the present report, we describe a case of such injury with irreparable radial head treated with patient-specific radial...
Article
The influences of 4 wt% bismuth addition and room temperature strain on microstructure and mechanical properties in tin alloys were investigated in this study. Commercially pure tin and Sn-4%Bi alloys were fabricated by permanent mold gravity casting. The samples were then subjected to forging process at room temperature. As-cast microstructures we...
Article
Ti-based amorphous alloys containing no harmful elements are desired. However, many Ti-based amorphous alloys contain toxic elements such as Al, Ni, V and Be. The presence of toxic elements within amorphous alloys is a concern when they are intended for use as a biomaterial. This problem has steered many researchers toward the development of Ti-bas...
Article
This paper reports on the addition of Al(H2PO4)3 binder solution with different vol% ratio and its effects on the mechanical behavior of the formed silicon dioxide ceramic. The starting material, commercial phosphate-bonded investment material, was analyzed by X-ray fluorescence (XRF) spectrometry. After silicon dioxide powder was mixed with a bind...
Article
This paper reports on the ferromagnetism of MgO powder and degraded powder at room temperature. The starting material, Mg(OH)2, was analyzed by X-ray fluorescence (XRF) spectrometry and then calcined at 450°C for 5 hours to obtain fresh MgO powder. The calcined powder was separated into two batches (i) kept in vacuum sealed (MgO-F) and (ii) kept at...
Article
In laser cutting, to work on sensitive and intricate materials, such as titanium, requires rigorous control of parameters to achieve the best cutting results due to high power throughput and rapid cutting speed. Titanium is known for severe reaction with oxygen and nitrogen at elevated temperatures, however the more inert argon assist gas is cost p...
Article
Full-text available
Ti based amorphous alloy exhibits excellent properties for biomedical applications. In general, it has high strength, low elastic modulus, good corrosion resistance and satisfactory biocompatibility. This work reported on a systematic study of a novel Ti44Zr10Pd10Cu6Co23Ta7, Ti44Zr10Pd10Cu10Co19Ta7 and Ti44Zr10Pd10Cu14Co15Ta7 metallic glass. Cylind...
Article
Gypsum-bonded investment, which is commonly used in gold casting, can cause several defects such as gas porosity from the decomposition of gypsum. Thus, the insight study in the behavior of gypsum-bonded investment can lead to resolve the problem in casting process. It consists of SiO2 (α-cristobalite and α-quartz) as a refractory and gypsum as a b...
Article
The Au-Sn soldering alloys are commonly used in microsoldering process for microelectronic industry due to fluxless process and relatively low melting temperature with good eutectic microstructures. This study investigated the microstructures of Au-Sn soldering between AlTiC and Si substrates with Ti/Pt/Au under bump metallization (UBM). The micros...
Article
Full-text available
Giant cell tumor of the bones occurring in the first metacarpals frequently requires entire metacarpal resection due to the aggressive nature and high rate of recurrence. Bone reconstruction can be performed with autogenous bone grafts. Here we describe a new technique of reconstruction using a patient-matched three-dimensional printed titanium fir...
Article
MgO powders were synthesized by a thermal decomposition method which was determined by differential scanning calorimetry coupled with thermogravimetric analysis (TG/DSC). The starting material, Mg(OH)2, was calcined at 400 °C, 450 °C and 500 °C for 1 h each to obtain the MgO powders. Phase composition, morphology and magnetic properties at room tem...
Article
Full-text available
Diffusion couples of pure gold and pure tin were created by mechanical cold rolling method. The couples were isothermally treated at temperatures slightly above and below the eutectic temperature near tin-rich region of the equilibrium phase diagram. Differences in the diffusion behaviors were observed as a function of treatment temperatures below...
Article
Full-text available
The soldered bonding between the Sn-Zn-Cu-Bi system and a Cu substrate was studied and reported herein. The alloying compositions were varied to investigate the effects of Zn, Cu, Bi contents on the solders’ melting temperature (Tm), microstructures, wettability and the intermetalliccompound (IMC) bonding with a Cu substrate. The Sn-7Zn and Sn-9Zn...
Conference Paper
Full-text available
The actual volume fraction of solid in semi-solid metal processing is critical to achieving the most effective semi-solid metal processing. The semi-solid slurry with different solid fractions shows different ability to fill molds. To determine suitable processing conditions for semi-solid sterling silver (92.5 wt.%), thermal analysis (TA), experim...
Article
In this paper we demonstrate a simple and rapid shape transformation of silver nanospheres (AgNSs) to silver nanoplates (AgNPls) using the oxidation and reduction capabilities of hydrogen peroxide. AgNPls having tunable surface plasmon resonance across the visible region with average size of 40–100 nm and thickness of 10–15 nm can be fabricated wit...
Chapter
Full-text available
The actual volume fraction of the solid in semi-solid metal processing is critical to achieving the most effective semi-solid metal processing. The semi-solid slurry with different solid fractions shows different ability to fill molds. To determine suitable processing conditions for semi-solid sterling silver (92.5 wt.%), thermal analysis (TA), exp...
Article
Full-text available
Titanium implants, such as bone plates, require compatible surface microtopography for bone cells adhesion and proliferation. To directly imitate complex natural bone structure, casting of different titanium alloys into natural bone structure investment was developed and compared. Major challenges are titanium’s high melting point as well as its hi...
Article
Pin-on-disk technique was used as a tool to study the tribological properties of contacting surfaces of alumina-titanium carbide composite material and diamond slicing blade. Conditions for testing are linear sliding speed between 0.2 and 0.4 m/s under applied load of 10 N and sliding distance up to 5000 m. The physical properties of both specimens...
Article
In recent years, the Au-Ge-Sb system has been studied as a possible alternative alloy for soldering applications [1-4]. The alloy has various fbenefits such as (i) low melting temperature which allows the alloy system to be used as a drop-in solution for high performance lead-free solders, (ii) three distinct phases of different hardness values (10...
Article
Alumina-titanium carbide composite (Al2O3-TiC) is one of advance ceramic matrix composites (CMC) that have been used in machining tool and tribology application because of its excellent mechanical properties. Powder processing is often a chosen method to produce this family of material, i.e. hot pressed (HP), hot iso-static pressed (HIP), and press...
Article
Gold based bulk metallic glass was synthesized at with different quenching rates. Au54Ag5Pd2Cu24.3Si14.7 alloy ingots were cast into wedge shape and cone shape samples. The critical casting thickness of this alloy composition was found to be 4 mm when cast in copper mold. Completely amorphous structure as found in sections thinner than 4 mm when co...
Article
Ti-based bulk metallic glass (BMG) is a new class of titanium alloys that exhibits excellent properties for biomedical applications. They have high strength, good corrosion resistance, low elastic modulus and satisfactory biocompatibility. Therefore, Ti-based BMG is an excellent alternative material to be used in biomedical application. Titanium al...
Article
Particularly in karat gold alloys in jewelry applications, many alloy formulations include a small amount of silicon for filigree castings and brightening effect [1]. On the other hand, some alloy manufacturers stayed away from silicon or set a maximum amount of silicon to avoid embrittlement [1-3]. However recent development of gold-based bulk met...
Article
Full-text available
The jewelry industry has been searching for sterling silver with high hardness values as it is believed by the industry to have direct effect on scratch resistance as well as improved mechanical properties such as “spring” property. Even though the direct relationship between hardness and how springy the jewelry articles are could not be linked. Ho...
Conference Paper
Recent discoveries of precious metal metallic glass have opened up a new processing pathway for jewelry manufacturing. This new class of metal alloy family does not have crystalline microstructure. The atoms are clustered together in a random, disordered fashion similar to those in plastics and glasses. Because of the atomic arrangement similarity,...
Article
We report here a simple yet efficient approach for fabricating large gold nanosheets using H2O2 as the reducing agent with starch as the stabilizer and shape-controlling agent. The weak reducing capability of H2O2 enables a kinetically controlled growth of nanosheets out of flower-like nanostructures formed at the early stage. Small nanosheets with...
Article
Full-text available
Recently, the cost factor of raw materials has emerged continuous improvement of tin-copper solder alloys. This work aims to improve the microstructural and mechanical properties of the eutectic tin-copper solder alloys by addition of nickel, cobalt and indium. The temperature profile of reflow soldering in surface-mount assembly was simulated to p...
Article
Full-text available
So far, only a single case of nickel-induced pemphigus has been reported in the literature. We present a case of a 49-year-old male who had experienced a desquamative gingivitis on the anterior mandibular region which was in contact with porcelain crowns and bridges and severe ulcerations on the right and left buccal mucosa. The lesions did not res...
Conference Paper
Full-text available
Metallic glasses have unique combination of the two most-desired properties of materials: superior strength and ease of fabrication. Metallic glasses of any alloy family have 200-350% higher Elastic moduli when compared to their conventional crystalline counterparts. For fabrication, the alloys can be made viscous and formed near-net-shape in the s...
Article
Full-text available
A novel thermoplastic bonding concept is demonstrated based on the unique rheological behavior and pattern-replicating ability of bulk metallic glass (BMG)-forming liquids. In this approach, the BMG is heated above Tg to the “supercooled liquid” region while a small normal force is applied to the joint. This results in liquid reflow, wetting and a...
Article
Families of bulk metallic glass (BMG) forming alloys based on precious metal platinum and gold are introduced. The gold-based BMGs have a gold content resulting in 18 karat alloy. They show liquidus temperature as low as 370 °C, good processibility with a large supercooled liquid region reaching 60 °C and low critical cooling rate reflecting in max...
Article
Full-text available
We report on the solidification of Au49, Ag5.5, Pd2.3, Cu26.9, Si16.3 bulk metallic glass under various strain rates. Using a copper mold casting technique with a low strain rate during solidification, this alloy is capable of forming glassy rods of at least 5 mm in diameter. Surprisingly, when the liquid alloy is splat cooled at much higher coolin...
Article
Full-text available
Gold-based bulk metallic glass alloys based on Au–Cu–Si are introduced. The alloys exhibit a gold content comparable to 18- karat gold. They show very low liquidus temperature, large supercooled liquid region, and good processibility. The maximum casting thickness exceeds 5 mm in the best glassformer. Au <sub>49</sub> Ag <sub>5.5</sub> Pd <sub>2.3<...
Article
Full-text available
The compositional dependence of a glass-forming ability (GFA) was systematically studied in a binary alloy series Cu100−xZrx (x=34, 36, 38.2, 40 at.%) by the copper mold casting method. Our results show the critical casting thickness jumps from below 0.5 mm to above 2 mm when x changes from 34 to 36 while further increase in x reduces the critical...
Article
Full-text available
In this paper, the model of genetic programming, one of the evolutionary computation methods, was developed to predict melting point and solidification range of solders. The training data set consisted of solidus/liquidus temperatures that were calculated from the calculation of the phase diagrams (CALPHAD) approach. The difference between the trai...
Article
Full-text available
The development of bulk metallic glass alloys is presented with various elemental selection criteria, design strategies, and experimental techniques. The focus was later drawn towards the development of noble bulk metallic glasses based on gold and platinum. To formulate a good bulk glass forming composition, we found that the gold alloys had to be...

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