Controlling and Minimizing Blistering during T6 Heat Treating of Semi-Solid Castings

2016 ◽  
Vol 256 ◽  
pp. 192-198 ◽  
Author(s):  
Hong Xing Lu ◽  
You Feng He ◽  
Stephen Midson ◽  
Da Quan Li ◽  
Qiang Zhu
Keyword(s):  
Solution Heat Treatment ◽  
Elevated Temperatures ◽  
Die Casting ◽  
Heat Treating ◽  
Pressure Casting ◽  
Shot Sleeve ◽  
Semi Solid ◽  
Entrapped Air ◽  
The Impact ◽  
Subsurface Defects

Surface blistering during T6 heat treating is an artifact that is essentially unique to high pressure casting processes such as semi-solid casting and die casting. It is believed that the blistering originates from subsurface defects present in the castings. When the castings are exposed to elevated temperatures during solution heat treatment, the strength of the aluminum is reduced, and the defects expand to deform the surfaces of the castings. There are three potential sources for the subsurface defects - entrapped air, die lubricant or shot sleeve lubricant.This paper will report on a study to determine the origin of the defects present in the castings that produce the blisters. Along with attempting to separate the influence of air and the two types of lubricants on blister formation, the study will also examine the impact of a number of process parameters on blistering.

scholarly journals Non isothermal simulation of non-Newtonian flow in the shot sleeve of semi-solid die casting processes

PAMM ◽  
2012 ◽  
Vol 12 (1) ◽  
pp. 481-482
Author(s):  
Roudouane Laouar ◽  
Olaf Wünsch
Keyword(s):  
Die Casting ◽  
Shot Sleeve ◽  
Newtonian Flow ◽  
Semi Solid

ALUMINUM 360.0

Alloy Digest ◽  
1983 ◽  
Vol 32 (4) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Shear Strength ◽  
Elevated Temperatures ◽  
Die Casting ◽  
Heat Treating ◽  
General Purpose ◽  
Hot Cracking ◽  
Casting Alloy ◽  
Good Resistance ◽  
Temperature Performance

Abstract ALUMINUM 360.0 is a die-casting alloy having excellent castability, good strength and good resistance to corrosion. It is characterized by pressure tightness, resistance to hot cracking, strength at elevated temperatures and ability to be electroplated. It is a general-purpose casting alloy for such items as cover plates and instrument cases. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Al-245. Producer or source: Various aluminum companies.

Floating Behavior of Entrapped Gas in Semi-Solid Metal

2017 ◽  
Vol 898 ◽  
pp. 1254-1260
Author(s):  
Hong Xing Lu ◽  
Qiang Zhu ◽  
Da Quan Li ◽  
Fan Zhang
Keyword(s):  
Solution Heat Treatment ◽  
Die Casting ◽  
Casting Process ◽  
Acceptance Rate ◽  
Solid Metal ◽  
High Quality ◽  
Casting Technology ◽  
Die Casting Process ◽  
Semi Solid ◽  
Die Castings

Semi-solid die casting technology has great advantages at defects control and has been successfully used to produce high quality aluminum alloy components for several years. In this process, semi-solid metal with high apparent viscosity and low plunger velocity are used to avoid surface turbulence which is the main source of entrapped gas in conventional die casting processes. But, entrapped gas still has other sources, such as melting, pouring, surface flooding and confluence weld. Solution heat treatment is always used to strengthen semi-solid die castings. The entrapped gas leads to blister defects, which directly decreases the acceptance rate of semi-solid die castings. So, the entrapped gas is still a serious issue in semi-solid die casting process. We studied the floating behavior of entrapped gas bubble in semi-solid metal. Two floating models were established for gas bubbles with different sizes. These models were used to analyze the possibility of entrapped gas escaping from semi-solid metal in casting practice. The results showed that entrapped gas from feed billet could not escape from the semi-solid metal in the casting process of impeller, which was proved by experiment results. These results emphasized the importance of clean melt and semi-solid metal. Some advices were given at last for avoiding or removing the entrapped gas in semi-solid die casting process.

Development of the Gas Induced Semi-Solid Metal Process for Aluminum Die Casting Applications

2008 ◽  
Vol 141-143 ◽  
pp. 97-102 ◽  
Author(s):  
J. Wannasin ◽  
S. Junudom ◽  
T. Rattanochaikul ◽  
M.C. Flemings
Keyword(s):  
Solid Fraction ◽  
Die Casting ◽  
Casting Machine ◽  
Gas Bubbles ◽  
Solid Metal ◽  
Heat Extraction ◽  
Shot Sleeve ◽  
Semi Solid

A simple and efficient rheocasting process that has recently been invented is being developed for aluminum die casting applications. The process called Gas Induced Semi-Solid (GISS) utilizes the combination of local rapid heat extraction and agitation achieved by the injection of fine gas bubbles through a graphite diffuser to create semi-solid slurry. In the GISS process, the die casting machine and the process cycle remain little changed from those of conventional die casting. The GISS unit creates a low solid fraction of semi-solid slurry in the ladle during the ladle transfer to the shot sleeve. The semi-solid slurry is then poured directly into the shot sleeve. This paper presents the detailed description of the process. The results of the semi-solid die casting experiments with ADC10 alloy using the GISS process are also reported and discussed.

THERMOLD H10

Alloy Digest ◽  
1968 ◽  
Vol 17 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Elevated Temperatures ◽  
Die Casting ◽  
Heat Treating ◽  
Temperature Performance ◽  
Hot Work Steel

Abstract Thermold-H10 is a chromium-molybdenum hot work steel that exhibits excellent resistance to softening at elevated temperatures. It is recommended for hot punches and shears, mandrels, and aluminum die casting dies. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, and machining. Filing Code: TS-209. Producer or source: Cyclops Corporation.

Progressive Trends of Die Casting - Vacuum Treatment of Casting Mold

2015 ◽  
Vol 669 ◽  
pp. 103-109
Author(s):  
Ján Paško ◽  
Štefan Gašpár
Keyword(s):  
Rapid Development ◽  
Die Casting ◽  
Vacuum Treatment ◽  
Pressure Casting ◽  
Technological Parameters ◽  
Casting Technology ◽  
Mould Cavity ◽  
Internal Homogeneity ◽  
The Impact ◽  
Casting Production

In these days in foundry branch there is a rapid development of sectors of special casting technology with the aim to increase the quality and the efficiency of pressure casting production. Internal homogeneity of pressure casting, characterized by the extent of porosity can be affected by the setup of technological parameters of pressure casting and last but not least by vacuuming the moulds, that means to exhaust air and gases from the mould cavity. Contribution is specifically aimed on the analysing the impact of degassing pressure moulds on the porosity of pressure casting from EN AC43400 Alloy.

ILZRO 16

Alloy Digest ◽  
1972 ◽  
Vol 21 (5) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Creep Resistance ◽  
Elevated Temperatures ◽  
Die Casting ◽  
Heat Treating ◽  
Zinc Alloy ◽  
Casting Alloy ◽  
Cold Chamber

Abstract ILZRO 16 is a zinc-base die-casting alloy which was developed to have superior creep resistance at both ambient and elevated temperatures for processing in cold-chamber die-casting machines. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: Zn-14. Producer or source: Zinc and zinc alloy suppliers.

scholarly journals Industrial Semi-Solid Rheocasting of Aluminum A356 Brake Calipers

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
U. A. Curle ◽  
J. D. Wilkins ◽  
G. Govender
Keyword(s):  
Die Casting ◽  
Casting Process ◽  
Shot Sleeve ◽  
Process Stability ◽  
X Ray ◽  
Initial Stage ◽  
Heat Treated ◽  
Die Casting Process ◽  
Semi Solid ◽  
Pressure Die Casting

Industrial semi-solid casting trials of aluminum A356 brake calipers were performed over five days with the CSIR-RCS and high-pressure die casting process cell. Consecutive visual passed castings were used as the measure of process stability, and common defects between trials were categorized. Short fill results are erratic and caused by unintended underdosing by the furnace or incomplete billet discharge at the delivery point in the shot sleeve. Cold shuts can be significantly reduced by adjusting the shot control profile. Surface finish defects include surface roughness and staining caused by lubricant burn off. Visual passed castings display none of the above-mentioned external defects. X-ray examination and pressure testing of heat-treated castings from the consecutive visual passed castings show improvement over the five days. These initial-stage industrialization efforts pave the way for process commercialization.

CROMO-N

Alloy Digest ◽  
1964 ◽  
Vol 13 (1) ◽  
Keyword(s):  
Elevated Temperatures ◽  
Die Casting ◽  
Heat Treating ◽  
Low Carbon ◽  
Bethlehem Steel Corporation ◽  
High Chromium ◽  
Extrusion Press ◽  
Temperature Performance ◽  
Heat Checking ◽  
Resistance To Heat

Abstract CROMO-N tool steel is a low-carbon, high-chromium grade, specially developed to provide optimum resistance to heat-checking during service at elevated temperatures. It is recommended for aluminum die casting dies, extrusion press tooling, aluminum and copper forging dies, and mandrels for extruding all nonferrous materials. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: TS-142. Producer or source: Bethlehem Steel Corporation.

THERMOLD H23

Alloy Digest ◽  
1970 ◽  
Vol 19 (2) ◽  
Keyword(s):  
Elevated Temperatures ◽  
Die Casting ◽  
High Strength ◽  
Heat Treating ◽  
Good Resistance ◽  
Die Steel ◽  
Extrusion Dies ◽  
Temperature Performance ◽  
Heat Checking ◽  
Resistance To Heat

Abstract THERMOLD-H23 is a chromium-tungsten hot work tool and die steel characterized by high strength at elevated temperatures and good resistance to heat checking. It is recommend for extrusion dies and die casting dies. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: TS-227. Producer or source: Cyclops Corporation.

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