Article 1 Background     Degrading metal alloys have recently become substantial scientific and clinical interest due to their use as implant materials in bone surgery and cardiovascular surgery and other applications. Degradable iron-based implants were approved for cardiovascular surgery due to low distinctive inflammatory reactions. This article was to verify the usability of iron-based alloys with an open cell structure as a degradable bone replacement material, which provide an osteoconductive surface for the stimulation of osseous integration on and a degradation rate, which lead to overburden the regeneration ability of bone. Discussion -the pure iron powder compacts and The powder mixture compacts were sintered at sintering temperatures between 1050 and 1120 °C. the Sintering densities were obtained by adding small amounts of boron which give the formation of fine distributed small pores, the Phosphorus contents provide maximum density, but higher contents of phosphorus form the brittle intermetallic phases. while The addition of boron leads to lower densities, phosphorus help on increasing mechanical strength. Therefore, a powder mixture of Fe3P and carbonyl iron was prepared on these experiments to prepared Fe0.6P alloy. The sintered density of the various alloys is shown in  -cell toxicity tests were carried out To characterize the iron-based alloys in vitro using a perfusion chamber system to simulate the dynamic body environment. Fibroblasts were maintained successfully for the duration of the experiment. -the comparison between alloys shows, that cell counts on the iron and alloyed iron discs show cell proliferation with the highest proliferation calculated as 1.6 wt.-% phosphorus-containing alloys. -The study shows that use phosphorus can be strengthened by open-cell metal without the risk degradation decreasing rates as result shows that there is no inflammatory response on the bone or the surrounding tissue, which gives rise to the good biocompatibility of iron to be used in biomaterial applications.the picture below show electron microscopy of a metal foam produce by a Fe0.6P alloy. Challenge and Future Outlook      the implant studies display a large fraction of residual implant material, even after 12 months implantation time, which means that tests only give indications for the degradation time in vivo test. Thus show that further work has to be done to support increase the degradation rates on the iron alloys.  Article2 Background     Developing metals alloy is an important topic related to biomaterials studies. Scientists should consider highly corrosion resistant in addition to biocompatible, the bioresorbable metal alloys give superior functionality in some biomedical applications. Scientists make much more research on magnesium alloys and other metals but iron-based alloys were less studied. However, in most cases, it is reported that the passivation of the steel substrate leads to a too low dissolution rate. .

1. Article 1
Background
Degrading metal alloys have recently become substantial
scientific and clinical interest due to their use as implant
materials in bone surgery and cardiovascular surgery and other
applications. Degradable iron-based implants were approved for
cardiovascular surgery due to low distinctive inflammatory
reactions. This article was to verify the usability of iron-based
alloys with an open cell structure as a degradable bone
replacement material, which provide an osteoconductive surface
for the stimulation of osseous integration on and a degradation
rate, which lead to overburden the regeneration ability of bone.
Discussion
-the pure iron powder compacts and The powder mixture
compacts were sintered at sintering temperatures between 1050
and 1120 °C. the Sintering densities were obtained by adding
small amounts of boron which give the formation of fine
distributed small pores, the Phosphorus contents provide
maximum density, but higher contents of phosphorus form the
brittle intermetallic phases. while The addition of boron leads to
lower densities, phosphorus help on increasing mechanical
strength. Therefore, a powder mixture of Fe3P and carbonyl
iron was prepared on these experiments to prepared Fe0.6P
alloy. The sintered density of the various alloys is shown in
-cell toxicity tests were carried out To characterize the iron-
based alloys in vitro using a perfusion chamber system to
simulate the dynamic body environment. Fibroblasts were
maintained successfully for the duration of the experiment.
-the comparison between alloys shows, that cell counts on the
iron and alloyed iron discs show cell proliferation with the
highest proliferation calculated as 1.6 wt.-% phosphorus-

2. containing alloys.
-The study shows that use phosphorus can be strengthened by
open-cell metal without the risk degradation decreasing rates as
result shows that there is no inflammatory response on the bone
or the surrounding tissue, which gives rise to the good
biocompatibility of iron to be used in biomaterial
applications.the picture below show electron microscopy of a
metal foam produce by a Fe0.6P alloy.
Challenge and Future Outlook
the implant studies display a large fraction of residual
implant material, even after 12 months implantation time, which
means that tests only give indications for the degradation time
in vivo test. Thus show that further work has to be done to
support increase the degradation rates on the iron alloys.
Article2
Background
Developing metals alloy is an important topic related to
biomaterials studies. Scientists should consider highly corrosion
resistant in addition to biocompatible, the bioresorbable metal
alloys give superior functionality in some biomedical
applications. Scientists make much more research on
magnesium alloys and other metals but iron-based alloys were
less studied. However, in most cases, it is reported that the
passivation of the steel substrate leads to a too low dissolution
rate. To increase the corrosion rate the passivation can be
deteriorated by the inclusion of alloying elements, which form
local cathodes and thereby promote the anodic dissolution of the
iron-rich phase.
Discussion
-In this study, for the first time, iron-manganese-silver alloys
synthesized by additive manufacturing techniques. We can

3. define additive manufacturing as the process where a digital 3D
design data is depositing material by building up a component
in layers. Additive Manufacturing also called 3D printing in
some cases. Additive Manufacturing methods are used
increasingly in Series biomedical Production.
-Based on current studies, it illustrates that silver particles
effectively distributed in the matrix which can be obtained,
providing cathodic sites in the composite material.
-As a result of this study, a new method for processing of
immiscible materials is done. On basis of the Selective Laser
Melting technique and the presented TWIP-silver alloy starting
by the mechanical properties are which barely deteriorated
compared to pure TWIP steel, Ag-particles fairly homogenous
distribution in the TWIP-matrix is successfully achieved and
finally the dissolution rate has increased by the addition of
silver.
Challenges And Future Outlook
In the future, further research is needed to make scientists fully
understand the connection between silver content, alloy
performance, and processing concerning the corrosive and
mechanical behavior. For example, corrosion analysis has to be
deeply understood to clarify detailed chemical reactions
proceeding between the surrounding iron matrix and silver
particles.
the range of silver addition should be broadened much more to
fully evaluate the possible dissolution rates. The adaption of the
material properties needs Further developments to the stiffness
of bone tissue, acquire by part design based on non-stochastic
cellular structures. also, Long-term experiments are necessary
for evaluation of the mechanical properties in the course of the
degradation of the implant performance as well as the
degradation behavior in body ambiance in general.

4. References
[5] T. Niendorf, F. Brenne, P. Hoyer, D. Schwarze, M. Schaper,
R. Grothe, M. Wiesener, G. Grundmeier, and H. J. Maier,
“Processing of New Materials by Additive Manufacturing: Iron-
Based Alloys Containing Silver for Biomedical Applications,”
Metallurgical and Materials Transactions A, vol. 46, no. 7, pp.
2829–2833, May 2015.
[6] P. Quadbeck, R. Hauser, K. Kümmel, G. Standke, G.
Stephan, B. Nies, S. Rößler, and B. Wegener, “Iron Based
Cellular Metals For Degradable Synthetic Bone Replacement ,”
Iron Based Cellular Metals For Degradable Synthetic Bone
Replacement , (IFAM-DD), Fraunhofer Institute Ceramic
Technologies and Systems, InnoTERE GmbH, Ludwig-
Maximilians Universität München.
of adjacent bone tissue, achievable by part design based on
non-stochastic cellular structures.

5. [11,29]
Long-term ex-
periments are necessary for evaluation of the mechanical
performance in course of the degradation of the implant as
well as the degradation behavior in body ambience in
general. Finally, other formerly non-producible material
combinations will be contemplated for proc.